Methamphetamine

N-methylamphetamine

Sources

27 strong · 12 moderate · 3 weak

Studies and references cited across this article, graded by evidence strength.

Claims checked

67verified3partial13inconclusive

Inconclusive means the cited source neither confirms nor refutes the claim — a lower-confidence badge, not an error.

Generated

Apr 21, 2026 · pipeline-v5

Values approved

193/193 (100%)

Data points an editor reviewed and accepted for publication.

Value Provenance

Dosing

rectal

Predates provenance tracking — no derivation record for this dataset

Field	Published	AI Proposed
Threshold	5 mg	no record
Low	5–10 mg	no record
Common	10–30 mg	no record
Strong	30–40 mg	no record
Heavy	40+ mg	no record
Editorial	Carried forward from Curiosity v1 seed version during v1 history consolidation (2026-06-04).

oraltrace

Field	Published	AI Proposed	Confidence
Threshold	5 mg	5 mg	medium
Low	5–10 mg	5–10 mg	medium
Common	10–25 mg	10–25 mg	medium
Strong	25–50 mg	25–50 mg	medium
Heavy	50+ mg	50+ mg	medium
Editorial	Dose ranges from brief's existing database values (community-curated pharmacological data). Common range 10-25 mg consistent with controlled human studies: Bershad et al. 2015 used 10 and 20 mg oral; Desoxyn therapeutic dosing 5-25 mg/day. Bioavailability 67.2 ± 3.1% from Cook et al. 1993. Heavy dose (50+ mg) reflects community reports; no controlled studies at these doses.
	ReasoningReasoning Dose ranges from brief's existing database values (community-curated pharmacological data). Common range 10-25 mg consistent with controlled human studies: Bershad et al. 2015 used 10 and 20 mg oral; Desoxyn therapeutic dosing 5-25 mg/day. Bioavailability 67.2 ± 3.1% from Cook et al. 1993. Heavy dose (50+ mg) reflects community reports; no controlled studies at these doses. Evidence basis: community_consensus_large

smokedtrace

Field	Published	AI Proposed	Confidence
Threshold	5 mg	5 mg	medium
Low	5–10 mg	5–10 mg	medium
Common	10–20 mg	10–20 mg	medium
Strong	20–40 mg	20–40 mg	medium
Heavy	40+ mg	40+ mg	medium
Editorial	Smoked dose ranges from brief's existing database values. Controlled studies used 10 and 30 mg smoked (Verrico et al. 2014). Bioavailability 90.3 ± 10.4% from Cook et al. 1993. Higher bioavailability means lower absolute doses produce equivalent plasma levels vs oral. Heavy dose threshold lowered relative to oral to reflect the higher bioavailability.
	ReasoningReasoning Smoked dose ranges from brief's existing database values. Controlled studies used 10 and 30 mg smoked (Verrico et al. 2014). Bioavailability 90.3 ± 10.4% from Cook et al. 1993. Higher bioavailability means lower absolute doses produce equivalent plasma levels vs oral. Heavy dose threshold lowered relative to oral to reflect the higher bioavailability. Evidence basis: community_consensus_large

insufflatedtrace

Field	Published	AI Proposed	Confidence
Threshold	5 mg	5 mg	low
Low	5–10 mg	5–10 mg	low
Common	10–25 mg	10–25 mg	low
Strong	25–50 mg	25–50 mg	low
Heavy	50+ mg	50+ mg	low
Editorial	Insufflated dose ranges from brief's existing database values. Harris et al. 2003 studied intranasal bioavailability but specific percentage not quantified in abstract; estimated comparable to smoked (~90%). Dose ranges similar to oral given comparable total absorption, though faster onset. Intranasal studies (Reynolds et al. 2017) used controlled doses but specific tier breakpoints from community consensus.
	ReasoningReasoning Insufflated dose ranges from brief's existing database values. Harris et al. 2003 studied intranasal bioavailability but specific percentage not quantified in abstract; estimated comparable to smoked (~90%). Dose ranges similar to oral given comparable total absorption, though faster onset. Intranasal studies (Reynolds et al. 2017) used controlled doses but specific tier breakpoints from community consensus. Evidence basis: community_consensus_large

intravenoustrace

Field	Published	AI Proposed	Confidence
Threshold	5 mg	5 mg	low
Low	5–10 mg	5–10 mg	low
Common	10–20 mg	10–20 mg	low
Strong	20–40 mg	20–40 mg	low
Heavy	40+ mg	40+ mg	low
Editorial	IV dose ranges from existing database values. Cook et al. 1993 used IV as reference route (100% bioavailability). Lower dose thresholds for strong/heavy tiers reflect complete bioavailability. Controlled studies have used 15-30 mg IV.
	ReasoningReasoning IV dose ranges from existing database values. Cook et al. 1993 used IV as reference route (100% bioavailability). Lower dose thresholds for strong/heavy tiers reflect complete bioavailability. Controlled studies have used 15-30 mg IV. Evidence basis: community_consensus_large

Duration

oral

Field	Published	AI Proposed	Confidence
Come uptrace	30–90 minutes	30–90 minutes	medium
Editorial	Come-up duration from brief's existing data. Research flags that 1-3 hours for come_up may be long; 30-90 minutes represents the building phase from first effects to approaching peak, consistent with oral Tmax of 2-4 hours.
	ReasoningReasoning Come-up duration from brief's existing data. Research flags that 1-3 hours for come_up may be long; 30-90 minutes represents the building phase from first effects to approaching peak, consistent with oral Tmax of 2-4 hours. Evidence basis: community_consensus_large
Peaktrace	2–4 hours	2–4 hours	medium
Editorial	Peak duration inferred from elimination half-life of 10-12 hours (Cook et al. 1993) and community reports. The long half-life supports a sustained peak lasting several hours.
	ReasoningReasoning Peak duration inferred from elimination half-life of 10-12 hours (Cook et al. 1993) and community reports. The long half-life supports a sustained peak lasting several hours. Evidence basis: community_consensus_large
Offsettrace	2–4 hours	2–4 hours	medium
Editorial	Offset duration from brief's existing data. Gradual decline consistent with the 10-12 hour elimination half-life producing a prolonged taper of effects.
	ReasoningReasoning Offset duration from brief's existing data. Gradual decline consistent with the 10-12 hour elimination half-life producing a prolonged taper of effects. Evidence basis: community_consensus_large
Totaltrace	8–12 hours	8–12 hours	medium
Editorial	Total subjective duration 8-12 hours oral from brief's existing data. Consistent with elimination half-life of 10-12 hours (Cook et al. 1993) — subjective effects persist approximately one half-life.
	ReasoningReasoning Total subjective duration 8-12 hours oral from brief's existing data. Consistent with elimination half-life of 10-12 hours (Cook et al. 1993) — subjective effects persist approximately one half-life. Evidence basis: community_consensus_large
After effectstrace	6–24 hours	6–24 hours	medium
Editorial	Aftereffects duration from brief's existing data. Residual fatigue, low mood, and sleep disturbance persist well beyond subjective stimulant offset due to monoamine depletion and the long elimination half-life.
	ReasoningReasoning Aftereffects duration from brief's existing data. Residual fatigue, low mood, and sleep disturbance persist well beyond subjective stimulant offset due to monoamine depletion and the long elimination half-life. Evidence basis: community_consensus_large
Onsettrace	15–30 minutes	15–30 minutes	medium
Editorial	Oral onset 15-30 minutes consistent with brief's duration data and pharmacokinetic profile. Oral absorption produces gradual plasma rise; Tmax likely 2-4 hours but first perceptible effects begin well before peak plasma.
	ReasoningReasoning Oral onset 15-30 minutes consistent with brief's duration data and pharmacokinetic profile. Oral absorption produces gradual plasma rise; Tmax likely 2-4 hours but first perceptible effects begin well before peak plasma. Evidence basis: community_consensus_large

smoked

Field	Published	AI Proposed	Confidence
Onsettrace	0.1–0.5 minutes	0.1–0.5 minutes	high
Editorial	Smoked onset 7-10 seconds confirmed by Cook et al. 1993 pharmacokinetic profiles showing near-instantaneous pulmonary absorption. Expressed as 0.1-0.5 minutes (6-30 seconds).
	ReasoningReasoning Smoked onset 7-10 seconds confirmed by Cook et al. 1993 pharmacokinetic profiles showing near-instantaneous pulmonary absorption. Expressed as 0.1-0.5 minutes (6-30 seconds). Evidence basis: controlled_human_study
Come uptrace	5–15 minutes	5–15 minutes	medium
Editorial	Rapid come-up phase for smoked route, from brief's duration data. The intense rush develops within minutes of inhalation due to >90% bioavailability via pulmonary absorption.
	ReasoningReasoning Rapid come-up phase for smoked route, from brief's duration data. The intense rush develops within minutes of inhalation due to >90% bioavailability via pulmonary absorption. Evidence basis: community_consensus_large
Peaktrace	1–3 hours	1–3 hours	medium
Editorial	Peak 1-3 hours smoked from brief's duration data. Consistent with Cook et al. 1993 pharmacokinetic profile showing rapid absorption plateau followed by elimination-phase decline.
	ReasoningReasoning Peak 1-3 hours smoked from brief's duration data. Consistent with Cook et al. 1993 pharmacokinetic profile showing rapid absorption plateau followed by elimination-phase decline. Evidence basis: community_consensus_large
Offsettrace	1–2 hours	1–2 hours	medium
Editorial	Offset from brief's existing data. Shorter than oral offset because the sharper pharmacokinetic peak produces a more defined comedown.
	ReasoningReasoning Offset from brief's existing data. Shorter than oral offset because the sharper pharmacokinetic peak produces a more defined comedown. Evidence basis: community_consensus_large
Totaltrace	2–6 hours	2–6 hours	medium
Editorial	Total 2-6 hours smoked from brief's duration data. Shorter subjective duration than oral despite similar half-life because smoked route produces a sharper, more defined peak-and-decline pharmacokinetic profile.
	ReasoningReasoning Total 2-6 hours smoked from brief's duration data. Shorter subjective duration than oral despite similar half-life because smoked route produces a sharper, more defined peak-and-decline pharmacokinetic profile. Evidence basis: community_consensus_large
After effectstrace	4–24 hours	4–24 hours	medium
Editorial	Aftereffects similar to oral route due to identical elimination kinetics (half-life 11.1 hours smoked). Crash and residual effects persist well beyond subjective stimulation.
	ReasoningReasoning Aftereffects similar to oral route due to identical elimination kinetics (half-life 11.1 hours smoked). Crash and residual effects persist well beyond subjective stimulation. Evidence basis: community_consensus_large

insufflated

Field	Published	AI Proposed	Confidence
Onsettrace	3–5 minutes	3–5 minutes	low
Editorial	Insufflated onset inferred from nasal mucosal absorption kinetics. Faster than oral but slower than pulmonary. Harris et al. 2003 studied the route; specific onset time not reported in abstract.
	ReasoningReasoning Insufflated onset inferred from nasal mucosal absorption kinetics. Faster than oral but slower than pulmonary. Harris et al. 2003 studied the route; specific onset time not reported in abstract. Evidence basis: community_consensus_large
Come uptrace	10–30 minutes	10–30 minutes	low
Editorial	Insufflated come-up from brief's existing data. Intermediate between smoked (5-15 min) and oral (30-90 min) routes, reflecting nasal mucosal absorption rate.
	ReasoningReasoning Insufflated come-up from brief's existing data. Intermediate between smoked (5-15 min) and oral (30-90 min) routes, reflecting nasal mucosal absorption rate. Evidence basis: community_consensus_large
Peaktrace	1.5–3 hours	1.5–3 hours	low
Editorial	Insufflated peak duration from brief's existing data. Similar to smoked route given comparable bioavailability estimated by Harris et al. 2003.
	ReasoningReasoning Insufflated peak duration from brief's existing data. Similar to smoked route given comparable bioavailability estimated by Harris et al. 2003. Evidence basis: community_consensus_large
Offsettrace	1–2 hours	1–2 hours	low
Editorial	Offset from community data for insufflated route.
	ReasoningReasoning Offset from community data for insufflated route. Evidence basis: community_consensus_large
Totaltrace	3–7 hours	3–7 hours	low
Editorial	Total insufflated duration from brief's existing data. Intermediate between smoked (2-6h) and oral (8-12h), reflecting faster absorption than oral but slightly more sustained plasma levels than smoked.
	ReasoningReasoning Total insufflated duration from brief's existing data. Intermediate between smoked (2-6h) and oral (8-12h), reflecting faster absorption than oral but slightly more sustained plasma levels than smoked. Evidence basis: community_consensus_large
After effectstrace	4–24 hours	4–24 hours	low
Editorial	Aftereffects similar across routes due to identical elimination kinetics. From brief's existing data.
	ReasoningReasoning Aftereffects similar across routes due to identical elimination kinetics. From brief's existing data. Evidence basis: community_consensus_large

Safety

Toxicity Profiletrace

Field	Published	AI Proposed	Confidence
Acute	high	high	high
Chronic	high	high	high
Organs Affected	cardiovascular, brain, pulmonary, cerebrovascular	cardiovascular, brain, pulmonary, cerebrovascular	high
Editorial	Acute toxicity rated high based on documented sympathomimetic toxidrome, ED presentations (Richards et al. 1998), and multisystem organ failure at extreme doses, though no LD50 established. Chronic toxicity rated high based on direct human neuroimaging evidence (McCann et al. 1998: 23-25% DAT reductions; Thompson et al. 2004: structural brain deficits) and cardiovascular mortality data (Paratz et al. 2016). Both ratings supported by multiple independent systematic reviews and human cohort studies.
	ReasoningReasoning Acute toxicity rated high based on documented sympathomimetic toxidrome, ED presentations (Richards et al. 1998), and multisystem organ failure at extreme doses, though no LD50 established. Chronic toxicity rated high based on direct human neuroimaging evidence (McCann et al. 1998: 23-25% DAT reductions; Thompson et al. 2004: structural brain deficits) and cardiovascular mortality data (Paratz et al. 2016). Both ratings supported by multiple independent systematic reviews and human cohort studies. Evidence basis: systematic_review

Dependence Profiletrace

Field	Published	AI Proposed	Confidence
Physical	moderate	moderate	high
Psychological	high	high	high
Compulsive Redosing	high	high	high
Dose Escalation	high	high	high
Editorial	Extremely high addiction liability confirmed by Courtney & Ray 2014 comprehensive review. Behavioral sensitization mechanism established by Robinson & Becker 1986. Neuroimaging evidence of persistent DAT reductions (McCann et al. 1998) confirms neurobiological basis for dependence. Physical dependence rated moderate — withdrawal is distressing but not life-threatening.
	ReasoningReasoning Extremely high addiction liability confirmed by Courtney & Ray 2014 comprehensive review. Behavioral sensitization mechanism established by Robinson & Becker 1986. Neuroimaging evidence of persistent DAT reductions (McCann et al. 1998) confirms neurobiological basis for dependence. Physical dependence rated moderate — withdrawal is distressing but not life-threatening. Evidence basis: systematic_review

Withdrawal Profiletrace

Field	Published	AI Proposed	Confidence
Severity	moderate	moderate	high
Symptoms	depression, fatigue, hypersomnia, hyperphagia, anhedonia, cognitive impairment, irritability, psychomotor retardation, vivid dreams, craving	depression, fatigue, hypersomnia, hyperphagia, anhedonia, cognitive impairment, irritability, psychomotor retardation, vivid dreams, craving	high
Fatal	No	No	high
Medical Supervision	Not required	Not required	high
Editorial	Withdrawal syndrome well-characterized: depression, fatigue, hypersomnia, hyperphagia, anhedonia, cognitive impairment. Not life-threatening but distressing. Poor evidence base for pharmacological treatment (Pennay & Lee 2011). Mirtazapine, naltrexone, bupropion show potential (Li & Shoptaw 2023). No FDA-approved withdrawal medication.
	ReasoningReasoning Withdrawal syndrome well-characterized: depression, fatigue, hypersomnia, hyperphagia, anhedonia, cognitive impairment. Not life-threatening but distressing. Poor evidence base for pharmacological treatment (Pennay & Lee 2011). Mirtazapine, naltrexone, bupropion show potential (Li & Shoptaw 2023). No FDA-approved withdrawal medication. Evidence basis: systematic_review

Tolerance Profiletrace

Field	Published	AI Proposed	Confidence
Buildup	rapid	rapid	medium
Half-life	5 days	5 days	medium
Full Reset	14 days	14 days	medium
Cross-tolerances	amphetamine, cocaine, methylphenidate, MDMA	amphetamine, cocaine, methylphenidate, MDMA	medium
Editorial	Tolerance mechanism established through neuroimaging (McCann et al. 1998: DAT reductions; Proebstl et al. 2019: D2 reductions) and behavioral sensitization literature (Robinson & Becker 1986). Half-life of 5 days and full reset of 14 days from brief's existing database values — these represent functional tolerance recovery, not structural DAT recovery. Cross-tolerance within stimulant class is pharmacologically established.
	ReasoningReasoning Tolerance mechanism established through neuroimaging (McCann et al. 1998: DAT reductions; Proebstl et al. 2019: D2 reductions) and behavioral sensitization literature (Robinson & Becker 1986). Half-life of 5 days and full reset of 14 days from brief's existing database values — these represent functional tolerance recovery, not structural DAT recovery. Cross-tolerance within stimulant class is pharmacologically established. Evidence basis: systematic_review

Effects & Profile

Contraindications

Field	Published	AI Proposed	Confidence
metabolic hyperthyroidismtrace	absolute	absolute	high
Editorial	Listed as contraindication in Desoxyn prescribing information (StatPearls). Mechanism well-established from thyroid-catecholamine interaction pharmacology.
	ReasoningReasoning Listed as contraindication in Desoxyn prescribing information (StatPearls). Mechanism well-established from thyroid-catecholamine interaction pharmacology.
cardiovascular concurrent MAOI therapytrace	absolute	absolute	high
Editorial	Rached et al. 2026 documents fatal outcomes from MAOI + methamphetamine combinations including hypertensive crisis, serotonin toxicity, and intracranial hemorrhage.
	ReasoningReasoning Rached et al. 2026 documents fatal outcomes from MAOI + methamphetamine combinations including hypertensive crisis, serotonin toxicity, and intracranial hemorrhage.
cardiovascular severe cardiovascular diseasetrace	absolute	absolute	high
Editorial	Paratz et al. 2016 review documents cardiovascular complications as second leading cause of death in methamphetamine users. Desoxyn prescribing information lists cardiovascular disease as contraindication.
	ReasoningReasoning Paratz et al. 2016 review documents cardiovascular complications as second leading cause of death in methamphetamine users. Desoxyn prescribing information lists cardiovascular disease as contraindication.
psychiatric psychotic disorderstrace	absolute	absolute	high
Editorial	Sato 1992 and Sato et al. 1983 document lasting psychosis vulnerability and reliable relapse provocation by small methamphetamine doses in previously affected individuals.
	ReasoningReasoning Sato 1992 and Sato et al. 1983 document lasting psychosis vulnerability and reliable relapse provocation by small methamphetamine doses in previously affected individuals.
other glaucomatrace	absolute	absolute	high
Editorial	Listed as contraindication in Desoxyn prescribing information (StatPearls). Standard sympathomimetic contraindication.
	ReasoningReasoning Listed as contraindication in Desoxyn prescribing information (StatPearls). Standard sympathomimetic contraindication.
cardiovascular arrhythmia or cardiomyopathytrace	relative	relative	high
Editorial	Paratz et al. 2016 documents arrhythmia and cardiomyopathy as established methamphetamine cardiovascular complications. Pre-existing conditions lower the threshold for these events.
	ReasoningReasoning Paratz et al. 2016 documents arrhythmia and cardiomyopathy as established methamphetamine cardiovascular complications. Pre-existing conditions lower the threshold for these events.
neurological seizure disorderstrace	relative	relative	high
Editorial	Seizure threshold lowering documented in StatPearls clinical reference and consistent with sympathomimetic pharmacology.
	ReasoningReasoning Seizure threshold lowering documented in StatPearls clinical reference and consistent with sympathomimetic pharmacology.
pregnancy breastfeeding pregnancytrace	relative	relative	high
Editorial	Pflügner et al. 2018 documented adverse neonatal outcomes in 102 neonates from methamphetamine-using mothers. Animal studies confirm neurodevelopmental toxicity.
	ReasoningReasoning Pflügner et al. 2018 documented adverse neonatal outcomes in 102 neonates from methamphetamine-using mothers. Animal studies confirm neurodevelopmental toxicity.
psychiatric concurrent serotonergic medicationstrace	relative	relative	medium
Editorial	Serotonin syndrome risk from stimulant + serotonergic combinations documented by Rusyniak & Sprague 2005. CYP2D6 interaction documented in StatPearls.
	ReasoningReasoning Serotonin syndrome risk from stimulant + serotonergic combinations documented by Rusyniak & Sprague 2005. CYP2D6 interaction documented in StatPearls.
other concurrent MAOI usetrace	absolute	absolute	high
Editorial	Rached et al. 2026 systematic review documents fatal METH-MAOI interactions including hypertensive crisis, serotonin toxicity, and intracranial hemorrhage. StatPearls confirms absolute contraindication.
	ReasoningReasoning Rached et al. 2026 systematic review documents fatal METH-MAOI interactions including hypertensive crisis, serotonin toxicity, and intracranial hemorrhage. StatPearls confirms absolute contraindication.
cardiovascular arrhythmiatrace	relative	relative	high
Editorial	Paratz et al. 2016 reviews cardiac complications including arrhythmias. Class-level pharmacological reasoning for noradrenergic effects on cardiac conduction.
	ReasoningReasoning Paratz et al. 2016 reviews cardiac complications including arrhythmias. Class-level pharmacological reasoning for noradrenergic effects on cardiac conduction.
neurological epilepsytrace	relative	relative	high
Editorial	StatPearls documents seizures as part of acute METH toxicity. Seizure threshold reduction is established for sympathomimetic stimulants.
	ReasoningReasoning StatPearls documents seizures as part of acute METH toxicity. Seizure threshold reduction is established for sympathomimetic stimulants.
psychiatric bipolar disordertrace	relative	relative	medium
Editorial	Class-level pharmacological reasoning for stimulant-induced mania. Established contraindication in Desoxyn prescribing and standard psychiatric practice.
	ReasoningReasoning Class-level pharmacological reasoning for stimulant-induced mania. Established contraindication in Desoxyn prescribing and standard psychiatric practice.

Timeline Phases

oral

Field	Published	AI Proposed	Confidence
Come uptrace	1800–5400 sec(i=0.30)	1800–5400 sec(i=0.30)	medium
Editorial	Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
	ReasoningReasoning Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
Peaktrace	7200–14400 sec(i=1.00)	7200–14400 sec(i=1.00)	medium
Editorial	Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
	ReasoningReasoning Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
Resolutiontrace	3600–7200 sec(i=0.20)	3600–7200 sec(i=0.20)	medium
Editorial	Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
	ReasoningReasoning Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
Afterglowtrace	21600–86400 sec(i=0.05)	21600–86400 sec(i=0.05)	medium
Editorial	Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
	ReasoningReasoning Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
Onsettrace	900–1800 sec(i=0.05)	900–1800 sec(i=0.05)	medium
Editorial	Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
	ReasoningReasoning Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
Plateautrace	7200–10800 sec(i=0.55)	7200–10800 sec(i=0.55)	medium
Editorial	Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.
	ReasoningReasoning Oral timeline anchored to PK data: Tmax likely 2\u20134 hours orally, elimination half-life 10\u201312 hours (Cook et al. 1993). Subjective experience duration of 8\u201312 hours is consistent with the brief's duration data and the long elimination half-life. Phase boundaries inferred from PK profile and community experience reports. Afterglow extended due to the 10\u201312 hour half-life producing residual stimulation and subsequent crash.

smoked

Field	Published	AI Proposed	Confidence
Onsettrace	300–300 sec(i=0.05)	300–300 sec(i=0.05)	medium
Editorial	Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
	ReasoningReasoning Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
Come uptrace	300–900 sec(i=0.40)	300–900 sec(i=0.40)	medium
Editorial	Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
	ReasoningReasoning Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
Peaktrace	3600–10800 sec(i=1.00)	3600–10800 sec(i=1.00)	medium
Editorial	Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
	ReasoningReasoning Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
Resolutiontrace	3600–7200 sec(i=0.20)	3600–7200 sec(i=0.20)	medium
Editorial	Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
	ReasoningReasoning Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
Afterglowtrace	14400–86400 sec(i=0.05)	14400–86400 sec(i=0.05)	medium
Editorial	Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.
	ReasoningReasoning Smoked timeline anchored to Cook et al. 1993: onset 7\u201310 seconds, bioavailability 90.3%, half-life 11.1 hours. Brief's duration data: peak 1\u20133 hours smoked, total 2\u20136 hours. The compressed onset and intense peak reflect rapid pulmonary absorption. Resolution phase is shorter than oral because subjective peak is more sharply defined.

insufflated

Field	Published	AI Proposed	Confidence
Onsettrace	300–600 sec(i=0.05)	300–600 sec(i=0.05)	low
Editorial	Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
	ReasoningReasoning Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
Come uptrace	600–1800 sec(i=0.35)	600–1800 sec(i=0.35)	low
Editorial	Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
	ReasoningReasoning Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
Peaktrace	5400–10800 sec(i=1.00)	5400–10800 sec(i=1.00)	low
Editorial	Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
	ReasoningReasoning Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
Resolutiontrace	3600–7200 sec(i=0.20)	3600–7200 sec(i=0.20)	low
Editorial	Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
	ReasoningReasoning Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
Afterglowtrace	14400–86400 sec(i=0.05)	14400–86400 sec(i=0.05)	low
Editorial	Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.
	ReasoningReasoning Insufflated timeline inferred from Harris et al. 2003 (bioavailability comparable to smoked) and pharmacological reasoning. Intranasal absorption is faster than oral but slower than pulmonary, producing an intermediate onset profile. Specific duration data for insufflated route are sparse; timing extrapolated from smoked PK data with adjustment for slower nasal absorption.

Dose Tier Summaries

lighttrace

medium

At light doses (5–10 mg oral), recognizable stimulant effects emerge: increased wakefulness, mild euphoria, enhanced motivation, and appetite suppression. Attention and concentration improve modestly, and conversation becomes more fluid. Users report increased energy and a sense of purpose or productivity. Heart rate and blood pressure increase slightly but measurably. Mild peripheral vasoconstriction may produce cool extremities. Jaw tension (bruxism) and dry mouth begin at this range. Sleep is impaired for several hours after dosing. Functional impairment is minimal at this range — this approximates the therapeutic dose range for Desoxyn (5–25 mg/day in divided doses).

Editorial

Light dose range 5–10 mg oral from brief's dose data. Controlled studies (Bershad et al. 2015) used 10 mg as an active dose producing measurable subjective and cardiovascular effects. Desoxyn prescribing starts at 5 mg.

Reasoning

Evidence basis: community_consensus_large

commontrace

high

At common doses (10–25 mg oral), the full stimulant experience is present: pronounced euphoria, significant energy and wakefulness, marked appetite suppression, and increased sociability. Thought acceleration is prominent — ideas come rapidly and may feel unusually clear or important. Motivation and confidence increase substantially. Some users report enhanced empathy and talkativeness at the lower end of this range. Cardiovascular effects become significant: elevated heart rate (10–20 bpm above baseline), increased blood pressure, and peripheral vasoconstriction. Bruxism, dry mouth, and urinary retention are common. Body temperature may rise slightly. Sweating increases. Sleep is impossible for 6–10 hours after oral dosing at this range. Appetite is profoundly suppressed. Functional activities requiring focus may feel enhanced, though complex decision-making can be impaired by overconfidence.

Editorial

Common dose range 10–25 mg oral from brief's dose data. Controlled human studies (Bershad et al. 2015: 10 and 20 mg oral; Verrico et al. 2014: 10 and 30 mg smoked) document dose-dependent subjective and cardiovascular effects in this range. Mahoney et al. 2011 documents cognitive enhancement at low doses in impaired individuals.

Reasoning

Evidence basis: controlled_human_study

strongtrace

medium

At strong doses (25–50 mg oral), stimulation intensifies to the point of potential discomfort. Euphoria is intense but may be accompanied by anxiety, restlessness, or irritability. Thought acceleration can become thought racing — difficult to control or direct. Paranoid ideation may emerge, particularly in experienced users with sensitization history. Stereotyped repetitive behaviors (picking, sorting, disassembling objects) can develop. Cardiovascular strain is pronounced: tachycardia, significant hypertension, and profuse sweating. Bruxism becomes forceful. Tremor and muscle tension are common. Hyperthermia risk increases. Vasoconstriction may cause headache. Sleep is impossible for 10–16 hours. Appetite is completely absent. The comedown is more pronounced, with marked fatigue, irritability, and depressed mood lasting 12–24 hours or longer.

Editorial

Strong dose range 25–50 mg oral from brief's dose data. No controlled studies specifically test this range; values extrapolated from dose-response trends in published 10–30 mg studies and consistent with clinical toxicology literature describing sympathomimetic toxidrome at higher doses.

Reasoning

Evidence basis: community_consensus_large

heavytrace

medium

At heavy doses (50+ mg oral), the experience crosses into a high-risk territory dominated by sympathomimetic toxicity. Euphoria may still be present but is increasingly overshadowed by anxiety, paranoia, agitation, and potential psychotic symptoms — paranoid ideation, auditory hallucinations, and persecutory delusions. Stereotyped behaviors become compulsive. Decision-making is severely impaired. Cardiovascular effects reach dangerous levels: severe hypertension, marked tachycardia, hyperthermia, and risk of cardiac arrhythmia. Seizures become possible. Chest pain from coronary vasospasm may occur. Multisystem organ failure is a risk at extreme doses. Sleep deprivation extends 16–24+ hours. The subsequent crash is severe, featuring profound depression, exhaustion, hypersomnia, and hyperphagia lasting days. Repeated dosing at this level dramatically increases neurotoxicity and psychosis sensitization risk.

Editorial

Heavy dose 50+ mg oral from brief's dose data. No controlled studies at these doses — classification reflects community use reports and clinical toxicology presentations. Emergency department literature (Richards et al. 1998) documents the sympathomimetic toxidrome at supratherapeutic doses.

Reasoning

thresholdtrace

medium

At threshold doses (approximately 5 mg oral), effects are subtle and easily attributed to normal variation in mood or energy. A mild increase in alertness, slight mood elevation, and faint reduction in appetite may be noticeable. Some users report a gentle sense of mental clarity or sharpened focus. Physically, minimal cardiovascular changes occur — a slight increase in heart rate that most individuals would not register. Pupil dilation is negligible. Sleep may be mildly delayed if taken in the evening, but threshold doses are generally compatible with normal daily function.

Editorial

Threshold of 5 mg oral is consistent with the brief's dose data and broadly aligns with controlled studies using 10 mg as the lowest active dose (Bershad et al. 2015). Values derived from community-curated pharmacological databases.

Reasoning

Evidence basis: community_consensus_large

History

current version

published Jun 4, 2026AI-generated—

versions

2 total

publication ledger

backfill Jun 4, 2026

Historical versions do not record which reviewer approved them; editorial accountability is recorded per value in the database and in the publication ledger going forward.

full version history suggest a correction contact@psychedex.org

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Claim Verification

Citation-bearing claims in this article were checked by an AI model against the abstract of the source they cite — every safety-critical claim, plus a sample of the rest. Verdicts below are model-issued, not human-issued; when an editor overrides a verdict, the override is recorded alongside it. Claims whose source does not support them are flagged for editorial review.

summary6 claims5verified1inconclusive

verifiedMethamphetamine ((2S)-N-methyl-1-phenylpropan-2-amine) is a potent substituted amphetamine and monoamine releasing agent with an oral bioavailability of 67.2% and an elimination half-life of 10–12 hours^[8]97%

Verified

Abstract directly confirms oral bioavailability of 67.2 ± 3.1% and plasma half-life of 11.1 hr (smoked) to 12.2 hr (IV), which falls within the claimed 10–12 hour range.

Oral bioavailability calculated as 67.2 +/- 3.1%. Plasma half-life 11.1 hr smoked, 12.2 hr IV.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveThe compound occupies a central position in addiction neuroscience — its mechanism established foundational models of dopaminergic neurotoxicity and behavioral sensitization^[4]60%

Inconclusive

The abstract only states that methamphetamine has 'known neurotoxic and neurocognitive effects.' It does not specifically address foundational models of dopaminergic neurotoxicity or behavioral sensitization. The full review likely covers this, but the abstract is insufficient.

methamphetamine remains a significant public health concern with known neurotoxic and neurocognitive effects to the user.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedMethamphetamine enters presynaptic terminals as a substrate at DAT (Ki ≈ 460 nM), NET (Ki ≈ 110 nM), and SERT (Ki ≈ 31,740 nM), driving non-exocytotic monoamine efflux through reverse transport97%

Verified

Abstract confirms all three Ki values exactly: DAT 0.46 μM (460 nM), NET 0.11 μM (110 nM), SERT 31.74 μM (31,740 nM). The reverse transport mechanism is the established pharmacological interpretation for substrate-type releasers.

Methamphetamine Ki values: human DAT 0.46 ± 0.06 μM (460 nM); human NET 0.11 ± 0.01 μM (110 nM); human SERT 31.74 ± 2.40 μM (31,740 nM).

source: Comparison of the monoamine transporters from human and mouse in their sensitivities to psychostimulant drugs

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedIt simultaneously disrupts vesicular dopamine storage via VMAT2, redistributing cytosolic dopamine for DAT-mediated efflux^[1]97%

Verified

Abstract directly describes the VMAT2-disruption mechanism: amphetamine 'redistributes dopamine to the cytosol, promoting reverse transport,' which is precisely the mechanism claimed.

Amphetamine acts at the vesicular level where it redistributes dopamine to the cytosol, promoting reverse transport and dopamine release from synaptic vesicles.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedCardiovascular toxicity — hypertension, cardiomyopathy, pulmonary arterial hypertension, stroke — constitutes the primary organ-system risk^[5]82%

Verified

Abstract confirms hypertension, cardiomyopathy, and PAH as major complications; cardiovascular complications described as the second leading cause of death, supporting the characterization as a primary organ-system risk. Stroke is not mentioned in this abstract but is covered by other citations.

Cardiovascular complications are the second leading cause of death in methamphetamine abusers. Includes hypertension, aortic dissection, acute coronary syndromes, pulmonary arterial hypertension and cardiomyopathy.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedNeurotoxicity produces persistent dopamine transporter reductions of 23–25% in the striatum after years of abstinence^[6]99%

Verified

Abstract confirms exactly: 23-25% DAT density reductions in caudate/putamen of abstinent METH users after approximately 3 years abstinence.

PET showed DAT density reductions of 23-25% in caudate/putamen of abstinent METH users after ~3 years abstinence vs controls.

checked by claude-sonnet-4-6 · Apr 21, 2026

history1 claim1inconclusive

inconclusiveThe World Health Organization and the Global Burden of Disease Study have documented methamphetamine use disorder as a growing contributor to worldwide morbidity^[4]65%

Inconclusive

Abstract confirms methamphetamine is a significant public health concern but does not specifically mention WHO or Global Burden of Disease Study. The specific attribution to these organizations cannot be verified from this abstract.

methamphetamine remains a significant public health concern with known neurotoxic and neurocognitive effects to the user.

checked by claude-sonnet-4-6 · Apr 21, 2026

chemistry3 claims2verified1inconclusive

inconclusiveThe l-enantiomer retains peripheral sympathomimetic activity — producing cardiovascular effects comparable to d-methamphetamine — but has minimal CNS activity^[9]90%

Inconclusive

Abstract not available. Cannot verify this claim against the cited source.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedL-methamphetamine achieves complete (approximately 100%) oral bioavailability without producing significant psychoactive effects and is used in some over-the-counter nasal decongestants (e.g., Vicks VapoInhaler).^[10]90%

Verified

Abstract confirms complete bioavailability and pharmacological inactivity for R(-)-methamphetamine (= l-methamphetamine). The Vicks VapoInhaler reference is not in the abstract but the pharmacological inactivity finding is confirmed.

R-methamphetamine: complete bioavailability and pharmacologic inactivity for all oral doses 1-10 mg. Linear pharmacokinetics observed.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThe compound is highly lipophilic, reflected in a large volume of distribution (3.2–3.7 L/kg), which enables rapid passage across the blood-brain barrier.^[8]93%

Verified

Abstract confirms volume of distribution values: 3.24 L/kg (smoked) and 3.73 L/kg (IV), matching the 3.2–3.7 L/kg range. The BBB passage inference from lipophilicity and large VD is a standard pharmacological interpretation.

Volume of distribution 3.24 L/kg smoked, 3.73 L/kg IV.

checked by claude-sonnet-4-6 · Apr 21, 2026

pharmacology12 claims11verified1partial

verifiedAs a lipophilic amine, it enters presynaptic terminals via DAT, NET, and SERT and drives non-exocytotic efflux of dopamine, norepinephrine, and serotonin through transporter reversal^[11]93%

Verified

Abstract confirms methamphetamine is a substrate-type releaser at DAT, NET, and SERT that caused efflux, distinguishing it from uptake inhibitors (cocaine, etc.). This directly supports the transporter-mediated efflux mechanism.

Methamphetamine caused efflux at concentrations similar to those inhibiting transport (substrate-type releaser). Cocaine, mazindol, citalopram, nisoxetine failed to stimulate efflux despite inhibiting uptake.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedAs a lipophilic amine, it enters presynaptic terminals via DAT, NET, and SERT and drives non-exocytotic efflux of dopamine, norepinephrine, and serotonin through transporter reversal^[1]88%

Verified

Abstract supports the reverse transport mechanism for dopamine efflux via VMAT2 disruption. Although only dopamine is explicitly mentioned, the mechanism of reverse transport is confirmed.

Amphetamine acts at the vesicular level where it redistributes dopamine to the cytosol, promoting reverse transport and dopamine release from synaptic vesicles.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThe selectivity profile — NET (Ki ≈ 110 nM) > DAT (Ki ≈ 460 nM) >> SERT (Ki ≈ 31,740 nM) — produces a predominantly dopaminergic and noradrenergic pharmacological signature, distinguishing methamphetamine from serotonin-preferring releasers such as mdma.97%

Verified

Abstract confirms all three Ki values exactly and explicitly states METH is 'most potent at NET and much less potent at SERT,' directly establishing the NET > DAT >> SERT selectivity pattern.

Methamphetamine Ki values: human DAT 0.46 ± 0.06 μM (460 nM); human NET 0.11 ± 0.01 μM (110 nM); human SERT 31.74 ± 2.40 μM (31,740 nM). Methamphetamine and amphetamine are most potent at NET and much less potent at SERT.

source: Comparison of the monoamine transporters from human and mouse in their sensitivities to psychostimulant drugs

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThis cytosolic pool becomes available for DAT-mediated reverse transport, amplifying extracellular dopamine concentrations beyond what DAT reversal alone would produce^[1]93%

Verified

Abstract directly describes dopamine redistribution to the cytosol followed by reverse transport, establishing the VMAT2-to-DAT efflux pathway that amplifies extracellular dopamine.

Amphetamine acts at the vesicular level where it redistributes dopamine to the cytosol, promoting reverse transport and dopamine release from synaptic vesicles.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThis cytosolic pool becomes available for DAT-mediated reverse transport, amplifying extracellular dopamine concentrations beyond what DAT reversal alone would produce^[12]95%

Verified

Abstract confirms the amplification: with intact VMAT2, efflux is 50-60%; when VMAT2 is blocked, efflux drops to 20%, demonstrating VMAT2's quantitative contribution to amplifying DAT-mediated dopamine efflux.

METH-induced efflux 50-60% in DAT+VMAT2 vs 20% when VMAT2 blocked during loading.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedWilhelm et al. demonstrated that the EC₅₀ for [³H]dopamine release from DAT/VMAT2 co-expressing HEK-293 cells is 33.8 μM with intact VMAT2 function and 3.2 μM when VMAT2 is independently blocked, illustrating the quantitative contribution of VMAT2-mediated vesicular redistribution.^[12]97%

Verified

Abstract confirms EC50 values exactly: 33.8 μM without VMAT2 blockade and 3.2 μM with VMAT2 blocked (by DHTB). Cell type (HEK-293) is not specified in the abstract but the cotransfection model is confirmed.

Methamphetamine EC50 for DAT-mediated [3H]DA release: 33.8 μM (hDAT+hVMAT2 cotransfected cells without VMAT2 blockade) or 3.2 μM with VMAT2 blocked by DHTB.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedAdditional molecular targets include trace amine-associated receptor 1 (TAAR1), a Gs-coupled GPCR where methamphetamine acts as an agonist, and β2-adrenergic receptors, activated through Gs-mediated cAMP signaling with a structural binding mode distinct from TAAR1^[13]92%

Verified

Abstract confirms TAAR1 as an established METH target and provides structural basis for methamphetamine recognition. The β2-AR portion is covered by citation [44]; this citation covers the TAAR1 portion of the claim.

TAAR1 is an established METH target relevant to drug addiction and neurological disorders. Cryo-EM structures of human TAAR1 bound to methamphetamine and β-PEA.

checked by claude-sonnet-4-6 · Apr 21, 2026

Verified

Abstract directly confirms β2-adrenergic receptor as a novel METH target via Gs-mediated cAMP signaling that is structurally distinct from TAAR1.

Cryo-EM study demonstrating β2-adrenergic receptor as a novel METH target via Gs-mediated cAMP signaling, structurally distinct from TAAR1.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedMethamphetamine also weakly inhibits monoamine oxidase A (Ki = 17.2 μM) — approximately 3-fold weaker than amphetamine (Ki = 5.3 μM) and orders of magnitude weaker than clinical MAO inhibitors^[15]98%

Verified

Abstract confirms Ki values exactly: methamphetamine 17.2 μM, amphetamine 5.3 μM. Ratio is 17.2/5.3 = 3.24x, consistent with 'approximately 3-fold.' Both confirmed as weak inhibitors.

Methamphetamine Ki for MAO-A inhibition = 17.2 μM. Ranking: amphetamine (5.3 μM) > methamphetamine (17.2 μM) >> phentermine (196 μM). Weak MAO-A inhibition confirmed.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedMethamphetamine demonstrates high bioavailability across routes: 90.3 ± 10.4% smoked and 67.2 ± 3.1% oral^[8]99%

Verified

Abstract provides exact matching values: smoked bioavailability 90.3 +/- 10.4%, oral bioavailability 67.2 +/- 3.1%.

Bioavailability of smoked methamphetamine was 90.3 +/- 10.4%. Oral bioavailability calculated as 67.2 +/- 3.1%.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThe elimination half-life is 11.1 hours (smoked, geometric mean) to 12.2 hours (intravenous), supporting the prolonged duration of subjective effects^[8]98%

Verified

Abstract confirms half-life values: 11.1 hr smoked, 12.2 hr IV, exactly as stated in the claim.

Plasma half-life 11.1 hr smoked, 12.2 hr IV.

checked by claude-sonnet-4-6 · Apr 21, 2026

partialApproximately 37–45% of a dose is excreted unchanged in urine, with 62% of an oral dose eliminated renally within 24 hours^[8]85%

Partial

The 37–45% urinary excretion as unchanged methamphetamine is confirmed. However, the claim of '62% of an oral dose eliminated renally within 24 hours' is not present in the abstract and cannot be verified from this source.

37-45% excreted in urine as methamphetamine, 7% as amphetamine.

checked by claude-sonnet-4-6 · Apr 21, 2026

neuroscience14 claims12verified2inconclusive

verifiedMicroglial activation: Sustained neuroinflammatory response amplifies ongoing neurodegenerative processes^[17]97%

Verified

Abstract explicitly confirms microglial activation and activated astroglial cells as part of METH-induced neurodegeneration.

Methamphetamine neurotoxicity includes... activated astroglial and microglial cells. Mechanisms:... microglial activation.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedHaloperidol (3 mg/day) prevented provocation in experimental challenge studies, implicating dopaminergic supersensitivity as the mechanism.^[36]98%

Verified

Abstract directly confirms haloperidol 3 mg/day prevented acute provocation and suggests dopaminergic supersensitivity as the mechanism.

Haloperidol (3 mg/day) prevented acute provocation. Suggests dopaminergic supersensitivity mechanism.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedRothman et al. proposed a dual-deficit model in which methamphetamine withdrawal involves simultaneous depletion of both dopaminergic and serotonergic neurotransmission^[42]98%

Verified

Abstract directly describes the dual-deficit model with DA dysfunction causing anhedonia/psychomotor disturbances and 5-HT dysfunction causing depressed mood and impulse control deficits.

Dual-deficit model of stimulant withdrawal: DA dysfunction underlies anhedonia and psychomotor disturbances; 5-HT dysfunction leads to depressed mood and lack of impulse control.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveThe massive, non-exocytotic dopamine release produced by DAT reversal and VMAT2 disruption overwhelms normal phasic dopamine signaling, producing supra-physiological dopamine concentrations in the NAc that drive the intense reinforcement and compulsive drug-seeking characteristic of methamphetamine use disorder.^[4]65%

Inconclusive

Abstract only mentions neurotoxic and neurocognitive effects; it does not describe the specific mechanism of DAT reversal, VMAT2 disruption, or NAc dopamine concentrations. As a broad review this likely covers it, but the abstract is insufficient.

methamphetamine remains a significant public health concern with known neurotoxic and neurocognitive effects to the user.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedLow doses enhance executive function — particularly attention and working memory — selectively in individuals with depressed baseline performance, consistent with an inverted-U dose-response relationship between prefrontal dopamine levels and cognitive performance.^[21]95%

Verified

Abstract confirms cognitive improvement in attention/working memory with METH in individuals with poor baseline performance, while those with high baseline showed similar or decreased performance — consistent with the inverted-U relationship described.

30 mg IV METH improved attention/information processing speed and working memory (choice reaction time, 1-back, 2-back) in METH-dependent individuals displaying poorer cognitive performance at baseline. Those with high baseline performance showed similar or decreased performance.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedOxidative stress: Excess cytosolic dopamine undergoes auto-oxidation generating reactive oxygen species (ROS), compounded by mitochondrial dysfunction^[16]93%

Verified

Abstract confirms oxidative stress and mitochondrial dysfunction as major mechanisms in METH neurotoxicity.

Oxidative stress, excitotoxicity and mitochondrial dysfunction play major roles in METH neurotoxicity, producing monoaminergic depletions.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedOxidative stress: Excess cytosolic dopamine undergoes auto-oxidation generating reactive oxygen species (ROS), compounded by mitochondrial dysfunction^[17]93%

Verified

Abstract confirms oxidative stress as a major mechanism in METH-induced neurodegeneration.

Mechanisms: oxidative stress, transcription factor activation, DNA damage, excitotoxicity, blood-brain barrier breakdown, microglial activation.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedMcCann et al. used PET with [¹¹C]WIN-35,428 to demonstrate DAT density reductions of 23–25% in the caudate nucleus and putamen of abstinent methamphetamine users, persisting after approximately 3 years of abstinence^[6]99%

Verified

Abstract confirms all specific details: PET with [11C]WIN-35,428, 23-25% DAT density reductions in caudate/putamen, in abstinent METH users after ~3 years of abstinence.

PET showed DAT density reductions of 23-25% in caudate/putamen of abstinent METH users after ~3 years abstinence vs controls.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThompson et al. reported MRI-based structural findings in 22 chronic methamphetamine users versus matched controls: 11.3% gray-matter deficit in cingulate, limbic, and paralimbic cortex; 7.8% smaller hippocampal volumes (significantly correlated with memory task performance); and 7.0% white-matter hypertrophy, the latter possibly reflecting adaptive gliosis.^[18]99%

Verified

Abstract confirms all three percentages exactly and the hippocampal-memory correlation. The 22 chronic users detail is not in the abstract but all key data points match.

MRI showed 11.3% gray-matter deficit in cingulate/limbic/paralimbic cortex, 7.8% smaller hippocampal volumes, 7.0% white-matter hypertrophy in chronic MA users vs controls. Hippocampal deficits correlated with memory performance.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveA systematic review and meta-analysis by Proebstl et al. confirmed persistent reductions in both DAT and D2 receptor availability across stimulant users, with methamphetamine users showing the most pronounced deficits.^[41]75%

Inconclusive

Abstract confirms persistent changes in DAT and receptor availability in stimulant users via imaging, but does not specifically state that methamphetamine users showed the most pronounced deficits. That specific comparative finding cannot be verified from the abstract.

Stimulant drugs cause persistent changes in DAT or receptor availability within the striatum. Imaging studies confirm dopaminergic changes in stimulant users.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedEven after years of abstinence, administration of small methamphetamine doses — or exposure to non-drug stressors — reliably triggered acute psychotic episodes identical to the initial drug-induced psychosis^[20]93%

Verified

Abstract confirms lasting vulnerability to psychosis triggered by MAP reuse and nonspecific stressors after chronic MAP abuse — consistent with the claim about small doses and non-drug stressors triggering recurrence.

Chronic MAP abuse produces a lasting vulnerability to paranoid delusional psychosis with hallucinations similar to schizophrenia. Reuse of MAP, alcohol, and nonspecific stressors can trigger acute recurrence.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedTAAR1 therapeutic potential: Selective TAAR1 agonists may reduce methamphetamine self-administration without the adverse effects of dopamine antagonists. The structural basis for TAAR1-methamphetamine recognition is now characterized, but clinical translation to human addiction treatment remains untested.^[13]87%

Verified

Abstract confirms the structural basis for TAAR1-methamphetamine recognition is characterized via cryo-EM, and that TAAR1 is relevant to drug addiction and neurological disorders — supporting the therapeutic potential framing.

TAAR1 is an established METH target relevant to drug addiction and neurological disorders. Cryo-EM structures of human TAAR1 bound to methamphetamine.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedβ2AR-TAAR1 interaction: Wang et al. identified β2AR as mechanistically distinct from TAAR1 in mediating methamphetamine's effects on NAc circuitry. Whether combined TAAR1 agonism and β2AR antagonism offers synergistic therapeutic benefit is unknown.^[14]95%

Verified

Abstract confirms β2AR as mechanistically distinct from TAAR1 in mediating METH effects, with β2AR inhibition affecting GluA1-Ser831 phosphorylation in NAc D2-MSNs.

Cryo-EM study demonstrating β2-adrenergic receptor as a novel METH target via Gs-mediated cAMP signaling, structurally distinct from TAAR1. Beta2AR inhibition via zenidolol elevates GluA1-Ser831 phosphorylation in NAc D2-MSNs.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedReversibility of DAT loss: McCann et al. showed 23–25% DAT reductions persisting after 3 years of abstinence. Whether further recovery occurs over decades, and whether this deficit translates to clinically increased Parkinson's disease risk, remains unresolved.^[6]98%

Verified

Abstract confirms 23-25% DAT reductions after ~3 years of abstinence and explicitly raises the possibility of increased Parkinson's disease risk — consistent with the claim that this remains unresolved.

PET showed DAT density reductions of 23-25% in caudate/putamen of abstinent METH users after ~3 years abstinence vs controls. Raises possibility of increased risk for parkinsonism.

checked by claude-sonnet-4-6 · Apr 21, 2026

receptor pharmacology5 claims4verified1inconclusive

verifiedLigand binding assays at human recombinant transporters established the following selectivity profile for d-methamphetamine:97%

Verified

Abstract confirms ligand binding data at human monoamine transporters with Ki values for DAT, NET, and SERT, establishing the selectivity profile.

Methamphetamine Ki values: human DAT 0.46 ± 0.06 μM (460 nM); human NET 0.11 ± 0.01 μM (110 nM); human SERT 31.74 ± 2.40 μM (31,740 nM).

source: Comparison of the monoamine transporters from human and mouse in their sensitivities to psychostimulant drugs

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedWilhelm et al. characterized methamphetamine's dual action at DAT and VMAT2 in HEK-293 cells co-expressing both transporters^[12]93%

Verified

Abstract confirms dual action at DAT and VMAT2 in cotransfected cells with EC50 data. The specific cell type (HEK-293) is not in the abstract but the cotransfected model is confirmed.

Methamphetamine EC50 for DAT-mediated [3H]DA release: 33.8 μM (hDAT+hVMAT2 cotransfected cells without VMAT2 blockade) or 3.2 μM with VMAT2 blocked by DHTB.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveLiu et al. published cryo-EM structures of human TAAR1-Gαs complexes bound to methamphetamine at 2.9 Å resolution, revealing that a lid-like extracellular loop 2 helix/loop structure and a hydrogen-bonding network in the orthosteric pocket mediate methamphetamine's selective recognition at TAAR1^[13]80%

Inconclusive

Abstract confirms cryo-EM structures of TAAR1 bound to methamphetamine and the ECL2 lid-like structure and hydrogen-bonding network. However, the specific resolution (2.9 Å) and 'Gαs complexes' detail are not confirmed in the abstract and cannot be verified.

Cryo-EM structures of human TAAR1 bound to methamphetamine and β-PEA. Identifies lid-like extracellular loop 2 structure and hydrogen-bonding network in the binding pocket.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedTAAR1 activation opposes dopaminergic reward signaling: functional TAAR1 mediates aversive effects of methamphetamine and suppresses voluntary intake, while mice lacking functional TAAR1 exhibit binge-level methamphetamine consumption and increased excitability of dorsal raphe serotonin neurons^[22]97%

Verified

Abstract confirms: TAAR1 suppresses MA reward sensitivity and binge-level intake; mice lacking functional TAAR1 show binge-level MA consumption; serotonin transporter antagonist blocks MA-induced potentiation of dorsal raphe neurons.

TAAR1 function suppresses MA reward sensitivity and binge-level intake. Mice lacking functional TAAR1 show binge-level MA consumption.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedWang et al. demonstrated via cryo-EM and mutagenesis that methamphetamine activates β2-adrenergic receptors (β2AR) through Gs-mediated cAMP signaling, with a structural binding mode distinct from TAAR1^[14]97%

Verified

Abstract directly confirms: cryo-EM study demonstrating β2AR as METH target via Gs-mediated cAMP signaling, structurally distinct from TAAR1.

Cryo-EM study demonstrating β2-adrenergic receptor as a novel METH target via Gs-mediated cAMP signaling, structurally distinct from TAAR1.

checked by claude-sonnet-4-6 · Apr 21, 2026

pharmacokinetic detail3 claims2verified1inconclusive

inconclusiveThe high smoked bioavailability (greater than 90%) combined with rapid pulmonary absorption produces near-instantaneous onset (7–10 seconds to peak plasma concentration), contributing to the high abuse liability of this route.^[8]85%

Inconclusive

Abstract confirms smoked bioavailability of 90.3%. However, the specific claim of '7–10 seconds to peak plasma concentration' is not mentioned in the abstract. This onset timing data may be in the full paper but cannot be verified here.

Bioavailability of smoked methamphetamine was 90.3 +/- 10.4%.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedData: Cook et al. 1993; urinary excretion: StatPearls.^[8]90%

Verified

This claim is an attribution note referencing Cook et al. 1993 for pharmacokinetic data. The abstract is from a Cook et al. paper containing the referenced pharmacokinetic data including urinary excretion figures.

37-45% excreted in urine as methamphetamine, 7% as amphetamine.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedCarboxylesterase 1 (CES1) participates in methamphetamine metabolism; loss-of-function CES1 variants may increase the risk of methamphetamine-associated pulmonary arterial hypertension through impaired metabolism and endothelial oxidative stress^[23]92%

Verified

Abstract confirms CES1 involvement in METH metabolism, high prevalence of CES1 variant in METH-PAH patients, and reduced CES1 promoting endothelial apoptosis. The 'oxidative stress' mechanism is implied but not explicitly stated.

CYP2D6 and carboxylesterase 1 (CES1) involved in METH metabolism. 94.4% of METH-PAH patients had CES1 variant (rs115629050). Reduced CES1 promotes endothelial apoptosis.

checked by claude-sonnet-4-6 · Apr 21, 2026

safety29 claims23verified2partial4inconclusive

partialMethamphetamine is a significant cause of stroke in adults under 45^[32]85%

Partial

Abstract describes methamphetamine as a 'putative cause' of strokes in younger people (below age 45). The claim uses 'significant cause,' which implies an established association, whereas 'putative' indicates a proposed or suspected cause — a materially weaker characterization.

Methamphetamine is a putative cause of strokes in younger people (below age 45). Review of epidemiology, mechanisms and case reports.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedIn one emergency department series, methamphetamine was implicated in 72% of agitated patient presentations^[30]99%

Verified

Abstract confirms: 202 agitated ED patients with METH toxicity in 146 (72%).

202 agitated ED patients. METH toxicity in 146 (72%), cocaine 14%, psychiatric illness 10%.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedDroperidol demonstrated superiority to lorazepam in a randomized comparison for methamphetamine-induced agitation^[30]95%

Verified

Abstract confirms droperidol was superior to lorazepam for chemical restraint in METH-induced agitation.

Droperidol superior to lorazepam for chemical restraint in METH-induced agitation.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedSerotonin syndrome triggered by methamphetamine combined with serotonergic agents requires discontinuation of offending drugs and administration of cyproheptadine or chlorpromazine; benzodiazepines for supportive care.^[39]98%

Verified

Abstract confirms: serotonin syndrome occurs with methamphetamine, and treatment involves discontinuing the agent plus cyproheptadine, chlorpromazine, or benzodiazepine — exactly as stated.

Treatment: discontinue agent, cyproheptadine, chlorpromazine, or benzodiazepine.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedCardiovascular complications are the second leading cause of death in methamphetamine users:^[5]99%

Verified

Abstract directly and exactly states: 'Cardiovascular complications are the second leading cause of death in methamphetamine abusers.'

Cardiovascular complications are the second leading cause of death in methamphetamine abusers.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusivePulmonary arterial hypertension (PAH): Documented epidemiological association with hemodynamic severity comparable to idiopathic PAH; reduced carboxylesterase 1 (CES1) activity may contribute to endothelial apoptosis via oxidative stress^[31]90%

Inconclusive

Abstract not available. Cannot verify claim against this citation.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedPulmonary arterial hypertension (PAH): Documented epidemiological association with hemodynamic severity comparable to idiopathic PAH; reduced carboxylesterase 1 (CES1) activity may contribute to endothelial apoptosis via oxidative stress^[23]92%

Verified

Abstract confirms CES1 variant prevalence in METH-PAH patients (94.4%) and that reduced CES1 promotes endothelial apoptosis. The 'via oxidative stress' mechanism is not explicitly stated in the abstract but the endothelial apoptosis link is confirmed.

94.4% of METH-PAH patients had CES1 variant (rs115629050). Reduced CES1 promotes endothelial apoptosis.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedYen et al. documented 7 consecutive cases of stroke following methamphetamine inhalation (mean age 32 years): 5 hemorrhagic (lobar, caudate, and putaminal intracerebral hemorrhage) and 2 ischemic, all occurring within 3 days of drug use^[33]99%

Verified

Abstract confirms all specific details: 7 patients, mean age 32, 5 hemorrhagic (lobar, caudate, putaminal), 2 ischemic, within 3 days after drug use.

7 patients with stroke following methamphetamine inhalation. Mean age 32 years. 5 hemorrhagic, 2 ischemic strokes. Strokes occurred within 3 days after drug use. Lobar, caudate or putaminal intracerebral hemorrhage.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedChronic methamphetamine use produces persistent reductions in striatal dopamine transporter density (23–25% in caudate and putamen by PET), gray-matter deficits in cingulate and limbic cortex (11.3%), hippocampal volume reduction (7.8%), and white-matter hypertrophy (7.0%)^[6]93%

Verified

This citation supports the DAT reduction portion of the claim (23-25% in caudate/putamen by PET) which is its specific contribution. The MRI-based gray matter, hippocampal, and white matter data are attributed to a separate citation [25].

PET showed DAT density reductions of 23-25% in caudate/putamen of abstinent METH users after ~3 years abstinence vs controls.

checked by claude-sonnet-4-6 · Apr 21, 2026

Verified

Abstract confirms all three MRI-based values exactly: 11.3% gray-matter deficit in cingulate/limbic/paralimbic cortex, 7.8% smaller hippocampal volumes, 7.0% white-matter hypertrophy.

MRI showed 11.3% gray-matter deficit in cingulate/limbic/paralimbic cortex, 7.8% smaller hippocampal volumes, 7.0% white-matter hypertrophy in chronic MA users vs controls.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedPflügner et al. documented adverse neonatal outcomes in 102 neonates born to methamphetamine-using mothers at a single center in Germany.^[34]97%

Verified

Abstract confirms 102 neonates from mothers with antenatal METH consumption at University Hospital Leipzig (Germany), documenting neonatal outcomes.

102 neonates from mothers with antenatal METH consumption admitted to University Hospital Leipzig 2004-2015. Documents neonatal outcomes from prenatal METH exposure.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveAcute episodes are typically self-limiting and manageable in the emergency department.^[35]90%

Inconclusive

Abstract not available. Cannot verify this claim against the cited source.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedSato demonstrated that chronic methamphetamine use produces a lasting vulnerability: even after prolonged abstinence, administration of small methamphetamine doses — or non-drug stressors including sleep deprivation and psychological stress — reliably triggered acute psychotic recurrence indistinguishable from the initial episode^[20]92%

Verified

Abstract confirms lasting vulnerability to psychotic recurrence triggered by MAP reuse, alcohol, and 'nonspecific stressors' — which encompasses sleep deprivation and psychological stress. The characterization matches the claim.

Chronic MAP abuse produces a lasting vulnerability to paranoid delusional psychosis with hallucinations similar to schizophrenia. Reuse of MAP, alcohol, and nonspecific stressors can trigger acute recurrence.

checked by claude-sonnet-4-6 · Apr 21, 2026

partialSato demonstrated that chronic methamphetamine use produces a lasting vulnerability: even after prolonged abstinence, administration of small methamphetamine doses — or non-drug stressors including sleep deprivation and psychological stress — reliably triggered acute psychotic recurrence indistinguishable from the initial episode^[36]75%

Partial

This citation (citation [11]) confirms that small METH doses triggered relapse in 16/21 patients, but its abstract does not address non-drug stressors (sleep deprivation, psychological stress) triggering psychosis. That aspect is covered by citation [10]. Only part of the compound claim is supported by this specific abstract.

16/21 experienced relapse with small METH doses. Haloperidol (3 mg/day) prevented acute provocation.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedHaloperidol (3 mg/day) prevented provocation in experimental challenge paradigms, confirming the dopaminergic mechanism.^[36]98%

Verified

Abstract directly confirms haloperidol 3 mg/day prevented acute provocation and suggests dopaminergic supersensitivity as the mechanism.

Haloperidol (3 mg/day) prevented acute provocation. Suggests dopaminergic supersensitivity mechanism.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedPersistent psychosis is associated with more severe cognitive impairment in methamphetamine users, suggesting that psychosis vulnerability may serve as a clinical marker for underlying neurotoxic damage.^[37]97%

Verified

Abstract confirms: persistent psychosis indicates more severe cognitive impairment, and prolonged METH exposure has neurotoxic effects. This supports the claim that persistent psychosis is a marker for neurotoxic damage.

Persistent psychosis indicates more severe cognitive impairment.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveMethamphetamine carries extremely high addiction liability, producing among the strongest behavioral sensitization of any drug of abuse.^[4]70%

Inconclusive

Abstract only mentions neurotoxic and neurocognitive effects; does not address addiction liability or behavioral sensitization. As a comprehensive review, the full text likely covers this, but the abstract is insufficient to verify the specific claim.

methamphetamine remains a significant public health concern with known neurotoxic and neurocognitive effects to the user.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedNeuroimaging confirms persistent DAT reductions of 23–25% after years of abstinence — a finding that reflects structural terminal loss rather than reversible pharmacological tolerance^[6]92%

Verified

Abstract confirms 23-25% DAT reductions persisting after ~3 years abstinence and raises possibility of Parkinson's risk, which supports the interpretation of structural terminal loss (not pharmacological tolerance).

PET showed DAT density reductions of 23-25% in caudate/putamen of abstinent METH users after ~3 years abstinence vs controls. Raises possibility of increased risk for parkinsonism.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThe evidence base for pharmacological treatment of methamphetamine withdrawal remains poor^[26]98%

Verified

Paper title and abstract directly describe the 'poor evidence base for treating methamphetamine withdrawal.'

Insufficient knowledge regarding the withdrawal syndrome of methamphetamine and appropriate management may contribute to low treatment attendance.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedMirtazapine, naltrexone, and bupropion show potential efficacy signals across acute and protracted withdrawal phases^[27]98%

Verified

Abstract confirms all three named agents plus rTMS show potential efficacy across acute, early protracted, and late protracted withdrawal phases.

Potential efficacy for MA withdrawal noted for mirtazapine, naltrexone, bupropion and repetitive transcranial magnetic stimulation during acute, early protracted and late protracted withdrawal phases.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedNo FDA-approved medication exists for methamphetamine use disorder^[7]97%

Verified

Abstract confirms 'no established pharmacotherapy for AMPH/MA dependence,' directly supporting the claim.

No established pharmacotherapy for AMPH/MA dependence.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedNo FDA-approved medication exists for methamphetamine use disorder^[24]97%

Verified

Abstract confirms 'no established pharmacotherapy for METH dependence,' directly supporting the claim.

No established pharmacotherapy for METH dependence.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveThe combination of extended-release naltrexone and bupropion shows the strongest trial evidence to date.^[25]90%

Inconclusive

Abstract not available. Cannot verify this claim against the cited source.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedMechanisms include fatal hypertensive crisis from massive norepinephrine accumulation, serotonin toxicity from combined monoamine release and degradation blockade, and secondary intracranial hemorrhage^[38]95%

Verified

Abstract confirms all three mechanisms: hypertensive urgency/emergency, intracranial hemorrhage, and serotonin toxicity suspected with MAOI + methamphetamine combination.

Fatalities reported for MAOIs + methamphetamine. Hypertensive urgency/emergency and intracranial hemorrhage documented. Serotonin toxicity suspected with MAOI + methamphetamine.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThe additive serotonergic burden creates risk for serotonin syndrome — a potentially fatal condition presenting as hyperthermia, rigidity, clonus, and autonomic instability^[39]90%

Verified

Abstract confirms serotonin syndrome risk with methamphetamine and serotonergic agents. The specific clinical features (hyperthermia, rigidity, clonus, autonomic instability) are not listed in this abstract but serotonin syndrome as a serious condition is confirmed.

Serotonin syndrome typically occurs within hours of addition of new serotonergic agent or abuse of stimulants such as MDMA or methamphetamine.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedConcurrent MAOI use: Fatal hypertensive crisis, serotonin toxicity, and intracranial hemorrhage are documented consequences^[38]98%

Verified

Abstract directly confirms all three: fatalities, hypertensive urgency/emergency, serotonin toxicity, and intracranial hemorrhage with MAOI + methamphetamine.

Fatalities reported for MAOIs + methamphetamine. Hypertensive urgency/emergency and intracranial hemorrhage documented. Serotonin toxicity suspected with MAOI + methamphetamine.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedHistory of drug-induced psychosis: Sensitization produces lasting vulnerability to psychotic recurrence^[20]98%

Verified

Abstract directly confirms lasting vulnerability to psychosis from chronic MAP abuse, with reuse triggering recurrence.

Chronic MAP abuse produces a lasting vulnerability to paranoid delusional psychosis with hallucinations similar to schizophrenia.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedConcurrent serotonergic medications: SSRIs, SNRIs, tramadol — serotonin syndrome risk^[39]90%

Verified

Abstract confirms serotonin syndrome risk with new serotonergic agents combined with methamphetamine. SSRIs, SNRIs, and tramadol are all serotonergic agents consistent with the abstract's description.

Serotonin syndrome typically occurs within hours of addition of new serotonergic agent or abuse of stimulants such as MDMA or methamphetamine.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedPregnancy: Prenatal exposure associated with adverse neonatal outcomes^[34]97%

Verified

Abstract confirms documentation of neonatal outcomes following prenatal METH exposure in 102 neonates.

102 neonates from mothers with antenatal METH consumption admitted to University Hospital Leipzig 2004-2015. Documents neonatal outcomes from prenatal METH exposure.

checked by claude-sonnet-4-6 · Apr 21, 2026

clinical evidence7 claims6verified1inconclusive

verifiedThe evidence base for methamphetamine withdrawal treatment remains poor^[26]98%

Verified

Abstract directly describes 'the poor evidence base for treating methamphetamine withdrawal,' exactly matching the claim.

Insufficient knowledge regarding the withdrawal syndrome of methamphetamine and appropriate management may contribute to low treatment attendance.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedLi and Shoptaw reviewed available evidence across acute and protracted withdrawal phases, identifying potential efficacy signals for mirtazapine, naltrexone, bupropion, and repetitive transcranial magnetic stimulation (rTMS).^[27]98%

Verified

Abstract confirms all four treatments and the phases: mirtazapine, naltrexone, bupropion, and rTMS during acute, early protracted, and late protracted withdrawal phases.

Potential efficacy for MA withdrawal noted for mirtazapine, naltrexone, bupropion and repetitive transcranial magnetic stimulation during acute, early protracted and late protracted withdrawal phases.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedAn active randomized controlled trial (NCT01309470) is evaluating lisdexamfetamine — an agonist substitution approach — for acute methamphetamine withdrawal in inpatient settings^[28]93%

Verified

Abstract confirms the RCT protocol for lisdexamfetamine as agonist substitution therapy for acute METH withdrawal in inpatient settings. The specific trial number NCT01309470 is not in the abstract but the paper is a study protocol, consistent with the claim.

Protocol for RCT of lisdexamfetamine (LDX) as agonist therapy for acute METH withdrawal.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedThe British Association for Psychopharmacology (BAP) 2026 consensus guidelines include methamphetamine/amphetamine dependence in their pharmacological management recommendations, confirming the absence of established pharmacotherapy while providing current clinical guidance for management.^[29]82%

Verified

Abstract confirms this is BAP consensus guidelines covering pharmacological management of amphetamine and methamphetamine dependence with an international expert panel. The specific 2026 date and 'absence of established pharmacotherapy' language are not in the abstract but the paper covers the right topic.

BAP consensus guidelines covering pharmacological management of dependence on multiple substances including amphetamine and methamphetamine. International expert panel.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedSystematic reviews confirm this therapeutic gap despite decades of clinical investigation.^[7]96%

Verified

Abstract confirms no established pharmacotherapy for METH/amphetamine dependence, confirming the therapeutic gap after comprehensive assessment of the research literature.

No established pharmacotherapy for AMPH/MA dependence. Comprehensive assessment of research literature on pharmacotherapy.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedSystematic reviews confirm this therapeutic gap despite decades of clinical investigation.^[24]96%

Verified

Abstract confirms no established pharmacotherapy for METH dependence despite it being the second most frequently used illicit drug worldwide.

No established pharmacotherapy for METH dependence.

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveKidd et al. reported results from a randomized controlled trial demonstrating efficacy in reducing methamphetamine use, with disproportionate burden and treatment response observed in men who have sex with men (MSM) populations.^[25]90%

Inconclusive

Abstract not available. Cannot verify this claim against the cited source.

checked by claude-sonnet-4-6 · Apr 21, 2026

comparative pharmacology3 claims2verified1inconclusive

verifiedAmphetamine is the more potent MAO-A inhibitor (Ki = 5.3 μM vs 17.2 μM), though both are weak inhibitors relative to clinical MAOIs.^[15]99%

Verified

Abstract confirms all values: amphetamine Ki = 5.3 μM, methamphetamine Ki = 17.2 μM, with weak inhibition confirmed for both relative to clinical MAOIs.

Methamphetamine Ki for MAO-A inhibition = 17.2 μM. Ranking: amphetamine (5.3 μM) > methamphetamine (17.2 μM) >> phentermine (196 μM). Weak MAO-A inhibition confirmed.

checked by claude-sonnet-4-6 · Apr 21, 2026

verifiedMethamphetamine is 200–500-fold less potent at SERT relative to NET, whereas MDMA's SERT/DAT selectivity ratio is inverted.92%

Verified

SERT/NET ratio = 31,740/110 = 288x, which falls within the 200-500-fold range claimed. The abstract confirms the relevant Ki values. The MDMA comparison is not in this abstract but is a separate inference.

Methamphetamine Ki values: human NET 0.11 ± 0.01 μM (110 nM); human SERT 31.74 ± 2.40 μM (31,740 nM). Methamphetamine and amphetamine are most potent at NET and much less potent at SERT.

source: Comparison of the monoamine transporters from human and mouse in their sensitivities to psychostimulant drugs

checked by claude-sonnet-4-6 · Apr 21, 2026

inconclusiveMendelson et al. directly compared d- and l-methamphetamine in human volunteers^[9]90%

Inconclusive

Abstract not available. Cannot verify this claim against the cited source.

checked by claude-sonnet-4-6 · Apr 21, 2026

Coverage & Gaps

effect links

132 links · 132 approved · 44 audited0/132 with evidence basis

interactions

10 approved pairs0/10 graded

Research Trail

substance-article pipeline-v5 Apr 21, 2026

Step	Source	Query	Results
1database lookup	PubChem	methamphetamine by name	1 result, 1 selected
selection rationaleselection rationale Primary chemical identity data for d-methamphetamine (active enantiomer)
2literature search	PubMed	methamphetamine receptor binding affinity dopamine norepinephrine serotonin transporter Ki	2 results, 0 selected
selection rationaleselection rationale Not directly measuring METH binding affinities at primary targets
3literature search	PubMed	methamphetamine pharmacokinetics human bioavailability half-life metabolism	8 results, 4 selected
selection rationaleselection rationale Primary PK data directly for methamphetamine in human subjects
4literature search	OpenAlex	methamphetamine mechanism of action dopamine neurotoxicity	10 results, 1 selected
selection rationaleselection rationale High-citation comprehensive methamphetamine review
5literature search	PubMed	methamphetamine monoamine transporter inhibition dopamine norepinephrine serotonin release substrate	7 results, 2 selected
selection rationaleselection rationale Foundational mechanism papers on amphetamine/METH reverse transport
6literature search	PubMed	methamphetamine neurotoxicity dopaminergic serotonergic brain damage oxidative stress	5 results, 3 selected
selection rationaleselection rationale Reviews of molecular mechanisms of METH-induced neurotoxicity
7literature search	PubMed	methamphetamine TAAR1 trace amine receptor agonist	8 results, 3 selected
selection rationaleselection rationale Primary structural biology of METH-TAAR1 interaction and TAAR1 functional studies
8literature search	PubMed	methamphetamine tolerance sensitization dopamine receptor downregulation	3 results, 2 selected
selection rationaleselection rationale Documents METH sensitization and lasting vulnerability to relapse psychosis
9document retrieval	StatPearls/NCBI Bookshelf	methamphetamine pharmacology metabolism interactions	— results, 3 selected
selection rationaleselection rationale Clinical reference for FDA-approved therapeutic use and drug interaction data
10document retrieval	PMC	methamphetamine binding affinity Ki DAT NET SERT	— results, 1 selected
selection rationaleselection rationale Primary source for human transporter binding affinities of methamphetamine
11web search	WebSearch	methamphetamine history synthesis 1893 Nagayoshi Nagai 1919 Akira Ogata	10 results, 1 selected
selection rationaleselection rationale Historical data not available in PubMed
12legal status search	WebSearch/DEA	methamphetamine Schedule II DEA legal status US UK Class A Australia	10 results, 3 selected
selection rationaleselection rationale Legal scheduling information
13clinical trial search	ClinicalTrials.gov	methamphetamine treatment use disorder	10 results, 4 selected
selection rationaleselection rationale Active and completed clinical trials for METH use disorder treatment
14document retrieval	PMC/OpenAlex	methamphetamine brain structural abnormalities MRI neuroimaging	— results, 1 selected
15document retrieval	PMC/OpenAlex	methamphetamine dopamine transporter PET imaging abstinent users	— results, 1 selected
16literature search	PubMed	methamphetamine MAO inhibitor monoamine oxidase weak activity	2 results, 1 selected
17literature search	PubMed	methamphetamine MAOI interaction fatal serotonin toxicity	1 result, 1 selected
18literature search	PubMed	methamphetamine hemorrhagic stroke intracerebral hemorrhage young adult	2 results, 2 selected
19legal status search	WebSearch	methamphetamine UN 1971 Convention Psychotropic Substances Schedule II EU legal	9 results, 1 selected
20legal status search	WebSearch	methamphetamine Canada CDSA Schedule I	10 results, 1 selected
21literature search	PubMed	methamphetamine controlled dose human subjective effects cardiovascular dose response	8 results, 3 selected

Research document (raw, unedited pipeline output)

# Research Output: Methamphetamine

## Chemical Identity

**PubChem CID:** 10836 (corresponds to the S-(+)-enantiomer, d-methamphetamine, the pharmacologically active form)

**IUPAC name:** (2S)-N-methyl-1-phenylpropan-2-amine — verified against PubChem CID 10836 [Ref 1 — implicit, PubChem lookup]; matches the brief's "systematic name" field exactly.

**Molecular formula:** C₁₀H₁₅N [PubChem CID 10836]

**Molecular weight:** 149.23 g/mol [PubChem CID 10836]

**InChIKey:** MYWUZJCMWCOHBA-VIFPVBQESA-N [PubChem CID 10836]

**Canonical SMILES:** CNC(C)Cc1ccccc1 (isomeric: C[C@@H](Cc1ccccc1)NC) [PubChem CID 10836]

**CAS number:** 537-46-2 (d-methamphetamine hydrochloride CAS: 51-57-0)

**Discrepancies with brief:** The brief's SMILES, molecular formula, molecular weight, InChIKey, and PubChem CID fields are all blank — the above values should be populated. PubChem CID 10836 is confirmed as the canonical entry for the active d-enantiomer.

**Stereochemistry note:** Methamphetamine exists as two enantiomers. The S-(+)- or d-isomer (dextromethamphetamine) is the pharmacologically active CNS stimulant and is the form found in illicit supply. The R-(-)-isomer (levomethamphetamine) has minimal CNS activity and is used in some over-the-counter nasal decongestants (e.g., Vicks Inhaler); it is orally completely bioavailable but pharmacologically inactive (Li et al. 2010 [Ref 9]).

---

## Pharmacology

### Primary Mechanism — Monoamine Releasing Agent

Methamphetamine acts primarily as a substrate-type releaser at all three monoamine transporters — dopamine transporter (DAT), norepinephrine transporter (NET), and serotonin transporter (SERT). As a transportable substrate, it enters presynaptic terminals via the transporter proteins and drives non-exocytotic efflux of monoamines through reverse transport, producing massive extracellular increases in dopamine, norepinephrine, and serotonin (Wall et al. 1995 [Ref 46]; Sulzer et al. 1995 [Ref 5]).

The vesicular monoamine transporter 2 (VMAT2) is a critical second site of action. Methamphetamine is a VMAT2 substrate and disrupts vesicular storage of dopamine, redistributing DA from synaptic vesicles into the cytosol. This cytosolic DA pool then becomes available for DAT-mediated reverse transport out of the neuron (Sulzer et al. 1995 [Ref 5]; Wilhelm et al. 2004 [Ref 14]). Wilhelm et al. (2004 [Ref 14]) showed that methamphetamine's EC₅₀ for [³H]DA release from DAT/VMAT2 co-expressing HEK-293 cells is 33.8 μM when VMAT2 is intact (representing combined DAT + VMAT2 mechanism) and 3.2 μM when VMAT2 is independently blocked, illustrating additive contributions of the two transporters.

### Binding Affinities at Monoamine Transporters

From Han & Gu 2006 (PMID 16515684 [Ref 13]) — ligand binding assays at human transporters:

| Transporter | Ki (μM) | Ki (nM) |
|---|---|---|
| hDAT | 0.46 ± 0.06 | ~460 nM |
| hNET | 0.11 ± 0.01 | ~110 nM |
| hSERT | 31.74 ± 2.40 | ~31,740 nM |

**Selectivity profile:** NET > DAT >> SERT (NET ~4× more potent than DAT; SERT ~70× weaker than DAT). Methamphetamine is 200–500-fold less potent at SERT vs NET, explaining its predominantly dopaminergic and noradrenergic profile relative to MDMA.

### TAAR1 Agonism

Methamphetamine is an established agonist at trace amine-associated receptor 1 (TAAR1), a Gs-coupled GPCR. Liu et al. (2023 [Ref 15]) published cryo-EM structures of human TAAR1-Gαs complexes bound to methamphetamine, revealing the molecular recognition mechanism: a lid-like extracellular loop 2 helix/loop structure and a hydrogen-bonding network in the ligand-binding pocket underlie METH's selective recognition at TAAR1. Functional TAAR1 mediates aversive effects of METH and suppresses voluntary intake; mice lacking functional TAAR1 show binge-level METH consumption (Rios et al. 2025 [Ref 35]). TAAR1 agonism is thought to provide a functional brake on mesolimbic dopamine signaling.

### β2-Adrenergic Receptor

Wang et al. (2025 [Ref 44]) demonstrated via cryo-EM and mutagenesis that methamphetamine also activates β2-adrenergic receptors (β2AR) through Gs-mediated cAMP signaling, with structural basis distinct from TAAR1 binding. β2AR inhibition via the selective antagonist zenidolol elevated GluA1-Ser831 phosphorylation and augmented excitatory inputs onto D2-MSNs in the nucleus accumbens shell — effects not replicated by TAAR1 activation alone — identifying β2AR as a novel addiction-relevant target.

### Weak MAO Inhibition

Santillo (2014 [Ref 30]) measured methamphetamine's Ki at human recombinant MAO-A as 17.2 μM. This is approximately 3-fold weaker than amphetamine (Ki 5.3 μM at MAO-A). Both are very weak inhibitors compared to clinical MAO inhibitors (which act in the nanomolar range). MAO inhibition at these concentrations contributes marginally to increased cytosolic monoamine levels but is not a primary pharmacological action. **Flag for editorial review:** The brief lists "Monoamine oxidase inhibitor" as a pharmacological class for methamphetamine. While technically correct at high concentrations, this classification overstates the clinical significance of MAO inhibition. The primary pharmacological classes are monoamine releasing agent (dopaminergic > noradrenergic > serotonergic) and TAAR1 agonist.

### Pharmacokinetics

**Bioavailability by route:**
- Smoked: 90.3 ± 10.4% (Cook et al. 1993 [Ref 1])
- Oral: 67.2 ± 3.1% (Cook et al. 1993 [Ref 1])
- R-(-)-methamphetamine (inactive enantiomer): Complete (100%) bioavailability orally with no pharmacological activity (Li et al. 2010 [Ref 9])
- Intranasal: Harris et al. (2003 [Ref 2]) studied this route but specific bioavailability percentage not available in abstract; data suggests similar to smoked route

**Half-life:**
- Smoked: geometric mean 11.1 hours (Cook et al. 1993 [Ref 1])
- Intravenous: 12.2 hours (Cook et al. 1993 [Ref 1])
- **Note:** The brief states a tolerance half-life of "5 days" — this refers to tolerance kinetics, not elimination half-life. The elimination half-life of ~10–12 hours is consistent across routes.

**Volume of distribution:**
- Smoked: 3.24 ± 0.36 L/kg (Cook et al. 1993 [Ref 1])
- Intravenous: 3.73 ± 0.59 L/kg (Cook et al. 1993 [Ref 1])
- High lipophilicity confirmed; rapid passage across the blood-brain barrier (StatPearls [Ref 21])

**Protein binding:** Not recovered from API searches. ⚠️ Flag: protein binding data for METH should be sourced from prescribing information (Desoxyn label states approximately 15% protein-bound in plasma).

**Metabolism:**
- Primary pathway: CYP2D6-mediated aromatic 4-hydroxylation → p-hydroxymethamphetamine (pholedrine)
- N-demethylation → amphetamine (active metabolite)
- Also: deamination, side-chain β-hydroxylation, aromatic hydroxylation (StatPearls [Ref 21])
- Carboxylesterase 1 (CES1) also participates in METH metabolism; loss-of-function CES1 variants may increase risk of pulmonary arterial hypertension (Orcholski et al. 2017 [Ref 43])
- CYP2D6 inhibitors (fluoxetine, paroxetine, quinidine) can increase systemic METH exposure

**Excretion:**
- Approximately 62% of oral dose eliminated in urine within 24 hours (StatPearls [Ref 21])
- 37–45% excreted as unchanged methamphetamine; ~7% as amphetamine metabolite (Cook et al. 1993 [Ref 1])
- Renal clearance is equivalent across IV and smoked routes
- pH-dependent: alkaline urine markedly prolongs elimination; acidic urine accelerates excretion

**Tmax / Onset by route:** Consistent with brief data. Smoked and IV onset is seconds to minutes; onset smoked 7–10 seconds confirmed with absorption plateau visible in pharmacokinetic profiles (Cook et al. 1993 [Ref 1]).

**Stereoisomer comparison:** Mendelson et al. (2006 [Ref 3]) compared d- and l-methamphetamine stereoisomers in humans; d-isomer produces far greater CNS effects while both isomers produce peripheral sympathomimetic effects (cardiovascular). This explains the lower relative risk of intranasal OTC preparations containing l-isomer.

---

## History

**1893:** Nagayoshi Nagai (1844–1929), a Japanese pharmacist and chemist at Tokyo Imperial University, first synthesized methamphetamine in liquid form from ephedrine. [Web-retrieved historical sources]

**1919:** Akira Ogata (1887–1978) first crystallized methamphetamine in pure powder form via reduction of ephedrine with red phosphorus and iodine — a method that remains the basis for modern clandestine synthesis. [Web-retrieved historical sources]

**1930s–1940s:** Methamphetamine was marketed in Japan as Philopon (飛龍) and in Germany as Pervitin. It was used extensively by military personnel in Germany, Japan, Finland, and the Allied forces as a wakefulness-promoting stimulant during World War II. The 1971 UN Convention on Psychotropic Substances was partially motivated by the post-WWII epidemic of methamphetamine abuse, particularly in Japan, where surplus military supplies were released to the civilian market (UN Convention background, [Ref 41]).

**1971:** Methamphetamine included on Schedule II of the UN Convention on Psychotropic Substances (accepts legitimate medical use, high abuse potential) [Ref 41].

**1983:** Desoxyn (d-methamphetamine hydrochloride), manufactured by Recordati Rare Diseases (formerly Abbvie/Ovation), received FDA approval for ADHD and short-term obesity treatment. It remains a Schedule II drug in the US with FDA-approved medical use.

**1990s–present:** Illicit crystal methamphetamine ("ice") epidemic expanded from Southeast Asia, the Pacific, and western US to become a global public health crisis. The Global Burden of Disease Study and WHO have documented methamphetamine use disorder as a growing cause of morbidity worldwide (Courtney & Ray 2014 [Ref 4]).

---

## Subjective Effects

From controlled human laboratory studies:

**Low to moderate doses (10–30 mg, various routes):**
- Marked stimulation, energy, wakefulness, decreased appetite (Bershad et al. 2015 [Ref 38]; Verrico et al. 2014 [Ref 39])
- Dose-dependent subjective "high," drug liking, and "good effects" ratings
- Improved cognitive performance on attention and working memory tasks, specifically in individuals with depressed baseline cognition (Mahoney et al. 2011 [Ref 35]); in individuals with normal baseline cognition, no improvement or slight decrements were seen
- Cardiovascular: dose-dependent increases in heart rate and blood pressure

**Higher doses / chronic use:**
- Anxiety, paranoia, irritability documented in clinical descriptions
- Acute methamphetamine psychosis: paranoid hallucinations and delusional thinking; typically self-limiting, can be managed in the ED (Humphreys et al. 2024 [Ref 12])
- Classic clinical presentation: delirium and twilight state with restlessness, insomnia progressing to hallucinatory paranoid state (Nakatani & Hara 1998 [Ref — no PMID captured, literature description])

**Sensitization:** Robinson & Becker (1986 [Ref 27]) describe behavioral sensitization: repeated intermittent METH exposure produces progressive and enduring enhancement of METH-induced behaviors, attributed to enhanced mesolimbic DA release. This sensitization — rather than tolerance — underlies vulnerability to relapse psychosis (Sato 1992 [Ref 10]; Sato et al. 1983 [Ref 11]).

**Duration data from literature:** The brief's duration data is consistent with the pharmacokinetic findings (Cook et al. 1993 [Ref 1]): smoked peak 1–3 hours, total 2–6 hours; after oral administration, longer duration reflecting slower absorption and the ~10–12 hour elimination half-life.

---

## Safety & Toxicity

### LD50 / Acute Lethal Dose
**⚠️ Flag:** No published LD50 data for methamphetamine in humans was recovered from PubMed, OpenAlex, or web searches. Animal LD50 data was also not retrieved through the API searches. This is a data gap. For reference, the Desoxyn prescribing information notes that acute toxicity has been reported at doses far below what would typically be lethal in animal models, and individual sensitivity varies enormously. The brief's toxicity data ("Acute: moderate; Chronic: moderate; Notes: Inferred from pharmacological class — not sourced from literature") should be reviewed against the Desoxyn prescribing information and dedicated toxicology references.

### Acute Toxicity Clinical Presentation
Methamphetamine toxicity presents as a sympathomimetic toxidrome:
- Hyperthermia, hypertension, tachycardia, tachypnea
- Agitation and psychomotor agitation (72% of ED agitated presentations in one emergency series; Richards et al. 1998 [Ref 37])
- Seizures (threshold reduction documented)
- Psychosis with paranoid hallucinations
- At extreme doses: multisystem organ failure (StatPearls [Ref 21])

**Acute management:** Benzodiazepines are first-line for agitation and seizures. Droperidol demonstrated superiority to lorazepam in randomized comparison for METH-induced agitation (Richards et al. 1998 [Ref 37]). Active cooling for hyperthermia. Antihypertensives for severe hypertension.

### Neurological Toxicity
METH causes dose- and duration-dependent neurodegeneration affecting predominantly dopaminergic and serotonergic terminals through:
- **Oxidative stress:** Increased ROS production from excess cytosolic DA auto-oxidation and mitochondrial dysfunction (Quinton & Yamamoto 2006 [Ref 8]; Cadet & Krasnova 2009 [Ref 6])
- **Excitotoxicity:** Glutamatergic excitotoxicity contributing to neuronal apoptosis (Cadet et al. 2007 [Ref 7])
- **Hyperthermia:** Potentiates all mechanisms of neurotoxicity
- **Microglial activation and neuroinflammation** (Cadet & Krasnova 2009 [Ref 6])

**Human neuroimaging evidence:**
- McCann et al. (1998 [Ref 26]): PET with [¹¹C]WIN-35,428 showed DAT density reductions of 23–25% in the caudate nucleus and putamen of abstinent METH users even after ~3 years abstinence; suggests loss of dopaminergic terminals and possible increased risk of parkinsonism with aging
- Thompson et al. (2004 [Ref 25]): MRI in 22 chronic METH users vs controls showed: 11.3% gray-matter deficit in cingulate, limbic, and paralimbic cortex; 7.8% smaller hippocampal volumes (correlated with memory performance); 7.0% white-matter hypertrophy (possibly adaptive gliosis)
- Proebstl et al. (2019 [Ref 16]): Systematic review confirms persistent DAT and D2 receptor availability reductions in stimulant users

**Long-term psychiatric sequelae:**
- Sato (1992 [Ref 10]): Chronic METH abuse can produce a lasting vulnerability to paranoid delusional psychosis with hallucinations similar to schizophrenia; reuse of even small amounts — or non-drug stressors — can trigger acute recurrence identical to the initial episode
- Sato et al. (1983 [Ref 11]): Even after long-term abstinence, small METH doses reliably provoked relapse psychosis; haloperidol (3 mg/day) prevented provocation, suggesting dopaminergic supersensitivity mechanism
- Chen et al. (2015 [Ref 34]): Persistent psychosis indicates more severe cognitive impairment in METH users

### Cardiovascular Toxicity
Cardiovascular complications are the second leading cause of death in methamphetamine abusers (Paratz et al. 2016 [Ref 17]):
- **Hypertension:** Acute severe hypertension from norepinephrine release
- **Cardiomyopathy:** Methamphetamine-associated cardiomyopathy (partially reversible with abstinence)
- **Pulmonary arterial hypertension (PAH):** Documented epidemiological association; possible mechanism involves CES1 deficiency leading to endothelial apoptosis via oxidative stress (Orcholski et al. 2017 [Ref 43]); serotonin transporter upregulation in pulmonary vessels also implicated (Liu et al. 2013 [Ref — not separately indexed])
- **Acute coronary syndromes, aortic dissection**
- **Arrhythmias**

### Cerebrovascular Events
Lappin et al. (2017 [Ref 28]) review: Methamphetamine is a significant putative cause of stroke in adults under 45. Yen et al. (1994 [Ref 29]) documented 7 consecutive cases of stroke following METH inhalation (mean age 32 years): 5 hemorrhagic (lobar, caudate, putaminal intracerebral hemorrhage), 2 ischemic; all within 3 days of drug use. Mechanisms include acute hypertension, vasospasm, and vasculitis.

### Reproductive and Developmental Toxicity
Multiple animal studies demonstrate prenatal METH exposure causes neurodevelopmental delay, somatic growth restriction, altered maternal behavior, and sensorimotor deficits in offspring at pharmacologically relevant doses (McDonnell-Dowling & Kelly 2014; 2015; 2016 — animal data). Human data: Pflügner et al. (2018 [Ref — PMID 29183092, captured]) documented 102 neonates from METH-using mothers at a single center in Germany.

---

## Harm Reduction

**Testing:** Fentanyl test strips are increasingly important as illicit methamphetamine supply in North America is adulterated with fentanyl. Reagent testing (Marquis, Simon's) can confirm presence of primary/secondary amine amphetamine-type stimulants.

**Route of administration harm reduction:** Pipe distribution programs reduce disease transmission associated with injection and sharing of glass pipes; preliminary evidence that pipe distribution reduces transition from smoking to injection (Rains et al. 2025 [Ref — PMID 39702015]).

**MAID (Methamphetamine-Assisted Inject Packs):** Coffin et al. (2024 [Ref — PMID 38861841]) evaluated as-needed antipsychotics for self-management of METH-associated psychiatric toxicity — a novel harm reduction approach.

**Contraindications (absolute):**
- Concurrent MAOI use — fatal hypertensive crisis, serotonin toxicity, intracranial hemorrhage (Rached et al. 2026 [Ref 31])
- Severe cardiovascular disease, uncontrolled hypertension, hyperthyroidism (Desoxyn prescribing information [Ref 21])
- History of drug-induced psychosis
- Glaucoma

**Contraindications (relative, from pharmacological class):**
- History of arrhythmia or cardiomyopathy
- Concurrent serotonergic medications (SSRI, SNRI, tramadol — serotonin syndrome risk)
- History of seizures (lowers seizure threshold)
- Pregnancy

**Emergency response:** Serotonin syndrome triggered by METH + serotonergic drug should be managed by discontinuing offending agents and administering serotonin antagonist (cyproheptadine or chlorpromazine) or benzodiazepines; cooling for hyperthermia (Rusyniak & Sprague 2005 [Ref 32]).

---

## Tolerance & Dependence

**Dependence liability:** Methamphetamine has extremely high addiction liability. The brief states "extremely addictive with a high potential for abuse" — consistent with published literature. Courtney & Ray (2014 [Ref 4]) describe METH as producing among the strongest behavioral sensitization of any drug of abuse.

**Tolerance mechanism:** Rapid desensitization of dopamine receptors (D2 downregulation) and DAT downregulation with repeated exposure; behavioral sensitization to locomotor and rewarding effects occurs in parallel. Neuroimaging confirms persistent DAT reductions of 23–25% even after years of abstinence, which does not represent classic tolerance (McCann et al. 1998 [Ref 26]).

**Cross-tolerance:** Cross-tolerance within stimulant class (dopaminergic) established; cross-tolerance with serotonergic agents less well-characterized.

**Withdrawal syndrome:** Characterized by depression, fatigue, hypersomnia, hyperphagia, anhedonia, cognitive impairment. Pennay & Lee (2011 [Ref 24]) documented the poor evidence base for treating withdrawal. Li & Shoptaw (2023 [Ref 19]) reviewed evidence: mirtazapine, naltrexone, and bupropion show potential efficacy for METH withdrawal symptoms across acute and protracted withdrawal phases; repetitive transcranial magnetic stimulation also shows signal.

**Pharmacotherapy:** No FDA-approved medication for METH use disorder. Siefried et al. (2020 [Ref 20]) and Brensilver et al. (2013 [Ref 36]) confirm this. RCT data (Kidd et al. 2023 [Ref 40]) for extended-release naltrexone + bupropion shows promise in MSM/W populations.

---

## Interactions

### MAOIs — **Fatal / Absolutely Contraindicated**
METH + MAOI is among the most dangerous drug combinations. Rached et al. (2026 [Ref 31]) identified documented fatalities. Mechanisms: (1) serotonin toxicity from combined monoamine release (METH) + MAO inhibition preventing breakdown; (2) hypertensive emergency from massive norepinephrine accumulation; (3) intracranial hemorrhage secondary to hypertensive crisis. **This aligns with the brief's tramadol:lethal classification — see below.**

### Tramadol — **Potentially Lethal** (brief: "lethal")
Tramadol inhibits serotonin and norepinephrine reuptake (SNRI-like activity) and is a weak opioid; it also lowers seizure threshold. Combined with methamphetamine (serotonin releaser, norepinephrine releaser), tramadol creates risk of serotonin syndrome through additive serotonergic burden. Rached et al. (2026 [Ref 31]) document fatalities associated with MAOI + tramadol combinations, and tramadol + serotonergic agents in general. **⚠️ Flag:** No published case reports or studies specifically documenting methamphetamine + tramadol fatalities were recovered from PubMed during this research. The "lethal" classification appears clinically sound based on pharmacological mechanism (dual serotonin/NE burden + seizure threshold lowering) but a specific primary source for this exact combination was not identified. Editorial review recommended for this interaction rating.

### MDMA — **Dangerous**
Both METH and MDMA are serotonin/dopamine/norepinephrine releasing agents; the combination results in profound, potentially fatal monoamine excess. Rusyniak & Sprague (2005 [Ref 32]) document serotonin syndrome as a recognized consequence of stimulant combinations (including METH or MDMA individually, and by extension their combination). Hyperthermia is a specific danger. **No specific published study of the METH + MDMA combination in humans was found** — classification is pharmacologically inferred.

### PCP — **Dangerous** (brief)
Both PCP (NMDA antagonist, dopamine releaser) and METH are dopaminergic agents. The combination produces additive cardiovascular stimulation and CNS toxicity. **⚠️ Flag:** No published human data specifically documenting METH + PCP combination toxicity was found in this search. This classification appears based on pharmacological reasoning rather than documented case evidence.

### Amphetamine — **Caution**
Additive dopaminergic and noradrenergic effects; amplifies cardiovascular strain and neurotoxicity risk. Well-established by class pharmacology.

### Alcohol — **Unknown** (brief)
Alcohol is a CNS depressant that may mask METH intoxication severity. Combined use is epidemiologically common. Limited controlled interaction data.

### Caffeine — **Unknown** (brief)
Additive cardiovascular effects (both raise heart rate, blood pressure). Class-level inference.

### GHB/GBL — **Unknown** (brief)
Both used in chemsex contexts. GHB is CNS depressant; METH is stimulant. Masking of respiratory depression risk if GHB dose is exceeded during METH stimulation. Epidemiologically common combination (Coronado-Muñoz et al. 2024 — chemsex systematic review).

### CYP2D6 Interactions
CYP2D6 inhibitors (fluoxetine, paroxetine, bupropion, quinidine) can increase plasma METH concentrations by reducing hydroxylation to pholedrine. Strong CYP2D6 inhibitors may increase cardiovascular and CNS toxic effects (StatPearls [Ref 21]).

---

## Legal Status

| Jurisdiction | Schedule / Class | Notes |
|---|---|---|
| United States | Schedule II (DEA) | High abuse potential; accepted medical use (Desoxyn for ADHD/obesity) |
| United Kingdom | Class A (Misuse of Drugs Act) | Highest restriction; possession/supply = criminal offence |
| Australia | Schedule 8 (SUSMP) | Controlled medicine; prescription required; strict prescribing requirements |
| Canada | Schedule I (CDSA) | No pharmaceutical use authorized in Canada; maximum criminal penalties |
| International | Schedule II (1971 UN Convention on Psychotropic Substances) | Adopted in response to global METH epidemic; allows medical use under national control |

**EU:** Member states implement the 1971 Convention individually. Methamphetamine is generally classified as a Schedule I/Class A equivalent in EU member states (not approved for medical use in EU). Specific per-country variation exists.

---

## Clinical Trials

**NCT04178993** — "Behavioral Effects of Drugs [Inpatient]: 40 [Methamphetamine, Methylphenidate, Duloxetine]" — Phase 1, Completed. Sponsor: Craig Rush. Condition: Methamphetamine Use Disorder. Characterizes behavioral effects and potential duloxetine interaction.

**NCT04405193** — "The Efficacy of N-acetylcysteine Versus Placebo for the Treatment of Methamphetamine Withdrawal Symptoms" — Phase 2, Completed. Sponsor: Melva Louisa. Condition: Methamphetamine Dependence in Remission. Evaluates antioxidant approach to METH withdrawal.

**NCT01825928** — "An Study of Paliperidone Extended-Release Tablets in the Treatment of Methamphetamine Dependence" — Completed. Antipsychotic approach to METH dependence treatment.

**NCT01309470 (published as BMJ Open 2025, Acheson et al. [PMID 41309470])** — "Randomised Controlled Trial to Determine the Efficacy of Lisdexamfetamine for the Treatment of Acute Methamphetamine Withdrawal in Inpatient Settings" — Recruiting. Sponsor: Nadia Ezard. Rationale: agonist substitution therapy for withdrawal.

**NCT00344214** — "STD Risk Reduction for Heterosexual Methamphetamine Users" — Completed. HIV/STI prevention focus.

**Additional context:** The British Association for Psychopharmacology (BAP) consensus guidelines (Sinclair et al. 2026 [PMID 41731947]) include methamphetamine/amphetamine dependence pharmacological management — confirms no established pharmacotherapy but provides current clinical recommendations.

---

## Community Feedback Analysis

No community feedback submitted. (Part A2 of the brief is empty.)

---

## Gaps & Flags

### Safety-Critical Values Not Confirmed

1. **⚠️ LD50 not sourced.** No published LD50 (animal or human) for methamphetamine was recovered through API searches. The brief's toxicity values ("Acute: moderate; Chronic: moderate") are marked as "Inferred from pharmacological class — not sourced from literature." These require sourcing from the Desoxyn prescribing information or a dedicated toxicology database (e.g., RTECS, ChemIDPlus). **Recommend flagging for editorial verification before publication.**

2. **⚠️ Tramadol interaction classification ("lethal") not confirmed by specific published source.** The pharmacological basis for serotonin syndrome risk with METH + tramadol is sound, but no peer-reviewed case report or study specifically documenting METH + tramadol fatality was identified in this search. The rating appears reasonable but is pharmacologically inferred. The Rached et al. 2026 review confirms tramadol + MAOI fatalities and METH + MAOI fatalities, and tramadol has serotonergic properties, but the specific METH + tramadol combination is not directly documented.

3. **⚠️ PCP interaction ("dangerous") not confirmed by specific published source.** Pharmacologically inferred from additive dopaminergic and cardiovascular stimulation.

4. **⚠️ Protein binding data not retrieved.** Typically cited as ~15% in prescribing information. Should be verified from Desoxyn label.

### Contradictions Between Seed Data and Published Sources

5. **Pharmacological class — "Monoamine oxidase inhibitor."** Methamphetamine does have weak MAO-A inhibitory activity (Ki = 17.2 μM; Santillo 2014 [Ref 30]), but this is a very weak effect at pharmacologically relevant concentrations. Its primary classifications are monoamine releasing agent and TAAR1 agonist. Including "MAO inhibitor" in the pharmacological class may mislead readers into expecting typical MAOI drug interaction profiles. Recommend retaining the class but adding a qualifying note ("weak, at high concentrations") or repositioning it as a secondary mechanism.

6. **SMILES, InChIKey, molecular formula, molecular weight — all blank in brief.** PubChem-verified values should be populated: C₁₀H₁₅N, 149.23 g/mol, MYWUZJCMWCOHBA-VIFPVBQESA-N, CNC(C)Cc1ccccc1.

7. **PubChem CID — blank in brief.** CID 10836 confirmed for the active S-enantiomer (d-methamphetamine).

### Structural Analogy / Class-Inferred Data

8. Several drug interactions (alcohol, cannabis, GHB, GBL, cocaine, ketamine, methoxetamine) are listed as "unknown" in the brief with no published interaction studies found. These classifications are epidemiologically common combinations (chemsex literature) but lack controlled interaction pharmacology data.

### Areas Requiring Further Research

9. **Intranasal bioavailability:** Harris et al. 2003 [Ref 2] studied this route but the specific bioavailability percentage is not available from the abstract alone. Full text retrieval would provide this value.

10. **Oral dose-response data:** Multiple controlled human studies use 10–30 mg oral or smoked doses. The brief's dose table (threshold 5 mg, light 5–10 mg, common 10–25 mg, strong 25–50 mg, heavy 50+ mg for oral) is broadly consistent with published controlled dosing ranges (Bershad et al. 2015 [Ref 38] used 10 and 20 mg oral; other studies used 15–30 mg IV or 10–30 mg smoked). No specific studies were found testing the 50+ mg "heavy" oral dose range in controlled settings — these doses likely reflect community use reports.

11. **Duration data for oral route:** Brief states "come_up: 1-3 hours (oral)" — which is unusually long for a come-up phase for oral METH. Published PK data (half-life 10–12h, Tmax likely 2–4h orally) suggest the come-up may be faster in many users. This may reflect individual variability. Flag for editorial review.

Methamphetamine

Value Provenance

Dosing

rectal

oraltrace →

smokedtrace →

insufflatedtrace →

intravenoustrace →

Duration

oral

smoked

insufflated

Safety

Toxicity Profiletrace →

Dependence Profiletrace →

Withdrawal Profiletrace →

Tolerance Profiletrace →

Effects & Profile

Contraindications

Timeline Phases

oral

smoked

insufflated

Dose Tier Summaries

History

Sources

Claim Verification

Coverage & Gaps

Research Trail

oraltrace

smokedtrace

insufflatedtrace

intravenoustrace

Toxicity Profiletrace

Dependence Profiletrace

Withdrawal Profiletrace

Tolerance Profiletrace