generation run 2026-05-10
72 min completedmodel pipeline-v5plan not recordedrun/6ef871bd…Selection
Verification
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The model's own caveats
3 further caveats recorded as free text — readable on the working page
Reproduce
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- 17 source keys (listed under Sources)
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25 searches — query, source, results, what was kept and why
| # | source | query | seen | kept | rationale |
|---|---|---|---|---|---|
| 1 | PubMed | 4-HO-MPT tryptamine psychedelic | 15 | — | — |
| 2 | WebSearch | 4-OH-MPT metabolism glucuronide N-oxide metabolites in vitro 2022 | 10 | 1 | — |
| 3 | PubMed | 4-hydroxy-N-methyl-N-propyltryptamine pharmacology | 15 | — | — |
| 4 | PubChem | 4-HO-MPT | 1 | 1 | Confirms all core chemical identity data for 4-HO-MPT |
| 5 | WebSearch | 4-HO-MPT legal status scheduling United States United Kingdom Australia | 10 | 3 | — |
| 6 | OpenAlex · absence | 4-HO-MPT meprocin tryptamine | 0 | — | — |
| 7 | PubMed | 4-hydroxy tryptamine serotonin receptor binding affinity psilocin analogue | 3 | 3 | Glatfelter 2023 directly studies 4-HO-MPT binding affinity; Glatfelter 2022 provides SAR context; Blair 2000 provides receptor pharmacology context |
| 8 | WebSearch | 4-HO-MPT TiHKAL Shulgin meprocin synthesis history | 10 | 2 | — |
| 9 | PubMed · absence | 4-OH-MPT metabolism in vitro human | 0 | — | — |
| 10 | PMC | 4-HO-MPT binding affinity Ki values | 1 | 1 | This is the primary source for 4-HO-MPT receptor binding affinity data |
| 11 | ClinicalTrials.gov · absence | 4-HO-MPT tryptamine psychedelic | 0 | — | — |
| 12 | WebFetch | UK Misuse of Drugs Act tryptamine generic definition | 1 | 1 | — |
| 13 | Erowid | 4-HO-MPT history effects dose legal | 1 | 1 | — |
| 14 | PubMed | tolerance cross-tolerance psychedelic 5-HT2A receptor downregulation | 1 | 1 | — |
| 15 | Cayman Chemical / CAS | CAS 77872-41-4 vs 763035-03-6 for 4-HO-MPT | 2 | 1 | Important: prevents CAS number confusion between 4-HO-MET and 4-HO-MPT |
| 16 | WebSearch | 4-HO-MPT class A United Kingdom Misuse of Drugs Act tryptamine | 10 | 2 | — |
| 17 | PubMed | tryptamine CYP450 monoamine oxidase metabolism | 2 | 2 | — |
| 18 | WebSearch | Repke Ferguson Bates 1981 Journal of Heterocyclic Chemistry tryptamine 4-hydroxy psilocin | 10 | 1 | — |
| 19 | PMC Glatfelter 2023 | 4-HO-MPT methyl-propyl binding affinity full table | 1 | 1 | — |
| 20 | Cayman Chemical | 4-HO-MPT CAS physical properties | 1 | 1 | — |
| 21 | Multiple | 4-HO-MPT dose duration comparison | 3 | 1 | — |
| 22 | WebSearch | 4-OH-MPT meprocin forensic identification NPS designer drug seized | 10 | 2 | — |
| 23 | Erowid TiHKAL | TiHKAL 4-HO-MPT entry 23 dose duration synthesis effects | 1 | 3 | — |
| 24 | WebSearch | pii/S2352007822002190 journal tryptamine 4-OH-MPT authors | 10 | 1 | — |
| 25 | Cross-reference synthesis | CAS number verification for 4-HO-MPT vs 4-HO-MET | 2 | 1 | — |
42 claims by section — every cited sentence, checked against its source
pharmacology11 · 9 ok
4-HO-MPT binds 5-HT2A with Ki = 114 nM, placing it in the moderate-affinity range for the classsupported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
The psychedelic effects of 4-HO-MPT are attributed to agonism at serotonin 5-HT2A receptors in the cerebral cortex, consistent with the established mechanism for the 4-hydroxytryptamine classsupported
4-acetoxy and 4-hydroxy compounds showed similar pharmacological effects. Tertiary amines induced HTR; secondary amines did not. acsptsci.2c00177
The psychedelic effects of 4-HO-MPT are attributed to agonism at serotonin 5-HT2A receptors in the cerebral cortex, consistent with the established mechanism for the 4-hydroxytryptamine classsupported
All novel tryptamines were partial or full 5-HT2A agonists. j.euroneuro.2016.05.001
At higher doses, 5-HT1A receptor activation (Ki = 106 nM) may produce sedation and hypothermic effects, as demonstrated for structurally similar tryptaminessupported
Results suggest role for 5-HT1A in tryptamine effects. pmid:11101361
By structural analogy with the 4-hydroxytryptamine class — where tertiary N,N-dialkyl substitution consistently produces partial or full 5-HT2A agonism — 4-HO-MPT is expected to behave as a partial to full agonist at this receptorsupported
Tertiary amines induced HTR; secondary amines did not. acsptsci.2c00177
By structural analogy with the 4-hydroxytryptamine class — where tertiary N,N-dialkyl substitution consistently produces partial or full 5-HT2A agonism — 4-HO-MPT is expected to behave as a partial to full agonist at this receptorsupported
All novel tryptamines were partial or full 5-HT2A agonists. j.euroneuro.2016.05.001
SERT affinity is low (Ki = 910 nM), indicating 4-HO-MPT is a cleaner receptor agonist without the serotonin-releasing properties of empathogenic tryptaminessupported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
Claim in pharmacology — inconclusiveinconclusiveworking →
This metabolic pattern mirrors that of the structural analogue 4-HO-MET.supported
Glucuronides and N-oxide recommended as forensic targets. j.forsciint.2018.06.037
Claim in pharmacology — inconclusiveinconclusiveworking →
By structural analogy with 4-HO-MET, CYP2D6 and/or CYP3A4 likely mediate the N-dealkylation and N-oxidation reactions. Monoamine oxidase A (MAO-A) is expected to contribute to oxidative deamination, as established for the tryptamine class generally.supported
DMT is metabolized primarily by MAO; rapid elimination; PK supports short duration of action of parenterally-administered tryptamines. s13318-023-00822-y
safety9 · 8 ok
{{Warning}}4-HO-MPT exhibits exceptionally potent 5-HT2B receptor affinity (Ki = 8 nM) — the highest-affinity target across all receptors tested and approximately 14-fold more potent than at the primary psychedelic target 5-HT2Asupported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
Class-level acute risks for 4-hydroxytryptamines include serotonin toxicity (particularly in combination with serotonergic drugs), sympathomimetic cardiovascular effects (tachycardia, hypertension), and hyperthermia at very high doses.supported
Comprehensive review of NPS tryptamines including structure, pharmacology, recreational use, toxicology, analytical methods, and case reports of death. 1570159x13666141210222409
HPPD (Hallucinogen Persisting Perception Disorder) — case reports exist for psilocin (the direct structural parent) and other serotonergic psychedelics. Class-level risk applies to 4-HO-MPT.supported
Case of HPPD after mixed psilocybin and cannabis use. Perceptual disturbances persisting >8 months. pmid:15963699
Claim in safety — inconclusiveinconclusiveworking →
Tolerance develops almost immediately after ingestion through 5-HT2A receptor downregulation (internalization and reduced surface expression) in the frontal cortexsupported
Repeated DOI causes 5-HT2A receptor downregulation in frontal cortex. Tolerance is 5-HT2A-dependent, beta-arrestin-2-independent. acschemneuro.2c00170
Cross-tolerance exists with all serotonergic psychedelics that act through 5-HT2A agonism, including lsd, psilocin, and DMT.supported
Cross-tolerance between DOI and LSD but not with non-psychedelic 5-HT2AR agonist lisuride. Tolerance is 5-HT2A-dependent. acschemneuro.2c00170
Tramadol combines weak SERT inhibition with opioid agonism and is classified as a dangerous interactionsupported
Tramadol inhibits SERT; FDA 2016 safety communication on opioid-serotonin interactions. Tramadol has highest serotonergic risk among opioids. Case reports of serotonin syndrome with tramadol and serotonergic drugs. s00204-018-2244-6
MAO-A is expected to be a primary degradation pathway for 4-HO-MPT; inhibiting it would dramatically amplify and prolong effects while increasing serotonin syndrome risk.supported
DMT is metabolized primarily by MAO; rapid elimination; PK supports short duration of action of parenterally-administered tryptamines. s13318-023-00822-y
Cardiac valvular disease (relative, specific to 4-HO-MPT) — the potent 5-HT2B affinity (Ki = 8 nM) warrants caution in individuals with pre-existing valvular pathology, though no clinical evidence exists for 4-HO-MPT-specific cardiac harmsupported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
pharmacokinetic-detail6 · 4 ok
Claim in pharmacokinetic-detail — inconclusiveinconclusiveworking →
The predominant clearance route is phase II conjugation at the 4-hydroxyl, consistent with the metabolic pattern observed for 4-HO-MET and 4-AcO-DiPT.supported
Glucuronides and N-oxide recommended as forensic targets. j.forsciint.2018.06.037
The predominant clearance route is phase II conjugation at the 4-hydroxyl, consistent with the metabolic pattern observed for 4-HO-MET and 4-AcO-DiPT.supported
Phase II: glucuronidation and sulfation. N-oxidation and N-dealkylation also occur. 6 metabolites identified. metabo12080705
Claim in pharmacokinetic-detail — inconclusiveinconclusiveworking →
Monoamine oxidase A (MAO-A) is expected to contribute to tryptamine catabolism via oxidative deamination, as established for DMT and related N,N-dialkyltryptaminessupported
DMT is metabolized primarily by MAO; rapid elimination; PK supports short duration of action of parenterally-administered tryptamines. s13318-023-00822-y
Carlier et al. (2022) recommended the following urinary biomarkers for confirming 4-HO-MPT intake:supported
4-OH-MPT-N-oxide and 4-OH-PT proposed as biomarkers. 17425255.2022.2166826
comparative-pharmacology5 · 3 ok
Claim in comparative-pharmacology — inconclusiveinconclusiveworking →
Direct comparison data from the same laboratory and assay methodology (Glatfelter et al. 2023, NIMH-PDSP) are available for several members of this class.supported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. acsptsci.2c00222
The 14-fold 5-HT2B selectivity over 5-HT2A (Ki 8 vs 114 nM) sets 4-HO-MPT apart from most characterized 4-hydroxytryptaminessupported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
Claim in comparative-pharmacology — inconclusiveinconclusiveworking →
4-HO-MPT shows minimal SERT affinity (Ki = 910 nM), consistent with a pure receptor agonist profile rather than the serotonin-releasing phenotype seen in empathogenic tryptamines (e.g., 5-MeO-DiPT, which shows higher SERT engagement)supported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
summary4 · 3 ok
Claim in summary — inconclusiveinconclusiveworking →
Radioligand binding data reveal a distinctive receptor profile: 5-HT2A Ki = 114 nM (primary psychedelic target), but the highest-affinity interaction is at 5-HT2B (Ki = 8 nM) — approximately 14-fold greater than at 5-HT2Asupported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
The potent 5-HT2B affinity constitutes an unresolved cardiac safety concern: chronic 5-HT2B agonism is associated with valvulopathy in other drug classes, though the relevance to infrequent psychedelic use is unknown. 4-HO-MPT does not produce physical dependence; tolerance develops rapidly via 5-HT2A receptor downregulation and resets within approximately 7 dayspartially supported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
The potent 5-HT2B affinity constitutes an unresolved cardiac safety concern: chronic 5-HT2B agonism is associated with valvulopathy in other drug classes, though the relevance to infrequent psychedelic use is unknown. 4-HO-MPT does not produce physical dependence; tolerance develops rapidly via 5-HT2A receptor downregulation and resets within approximately 7 dayspartially supported
Repeated DOI causes 5-HT2A receptor downregulation in frontal cortex. Tolerance is 5-HT2A-dependent, beta-arrestin-2-independent. acschemneuro.2c00170
receptor-pharmacology3 · 2 ok
Claim in receptor-pharmacology — inconclusiveinconclusiveworking →
At Ki = 8 nM versus 114 nM, the compound is 14-fold more potent at 5-HT2B than at 5-HT2Asupported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222
However, Glatfelter et al. (2023) did not perform in vivo testing on 4-HO-MPT directly — only the closely related prodrug 4-PrO-DMT received mouse behavioral evaluation in that study.supported
4-acetoxy and 4-propionoxy analogues showed weaker binding but similar target profiles. [Title: Effects of 4-Propionoxy-N,N-dimethyltryptamine in Mice] acsptsci.2c00222
history2 · 1 ok
In 1985, Repke collaborated with Grotjahn and Shulgin on a related study examining the closest structural analogue — 4-HO-MiPT (N-methyl-N-isopropyl, differing only in branching of the propyl chain) — which was described as producing 'a classic hallucinogenic profile' and identified as the most interesting compound in the series.supported
4-HO-MiPT (closest structural analogue to 4-HO-MPT) described as most interesting, producing classic hallucinogenic profile. pmid:4009612
Claim in history — inconclusiveinconclusiveworking →
clinical-evidence1 · 1 ok
The only systematic human-relevant experimental data is the in vitro hepatocyte metabolism study by Carlier et al. (2022), which characterized metabolic products but did not involve human dosing.supported
4-OH-MPT metabolism characterized in human hepatocytes. Seven metabolites identified via N-oxidation, N-demethylation, O-glucuronidation, O-sulfation. 17425255.2022.2166826
neuroscience1 · 1 ok
The potent H1 affinity (Ki = 92 nM) may modulate the neurological phenotype by introducing sedative and attention-dampening effects not typical of classical psychedelics with negligible histaminergic engagement.supported
Determined receptor binding profiles of various tryptamine-based psychedelics related to psilocybin. Includes 4-HO-MPT. acsptsci.2c00222