Mephedrone

# Research Output: Mephedrone

**PSX ID:** PSX-0243 | **Slug:** mephedrone | **Research Date:** 2026-04-20
**Provenance ID:** 25618495-032d-4439-b758-e10a0e03004e

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## Chemical Identity

**Verified via PubChem CID 45266826 [database lookup confirmed]:**

- **Molecular formula:** C₁₁H₁₅NO *(confirms brief's blank; fills gap)*
- **Molecular weight:** 177.24 g/mol (free base); 213.70 g/mol as HCl salt *(fills gap)*
- **IUPAC name:** 2-(methylamino)-1-(4-methylphenyl)propan-1-one *(matches brief's systematic name)*
- **SMILES:** `Cc1ccc(cc1)C(=O)C(C)NC` *(fills blank in brief)*
- **InChIKey:** YELGFTGWJGBAQU-UHFFFAOYSA-N *(fills gap)*
- **CAS number:** 1189805-46-6 *(web-retrieved; not in brief)*
- **PubChem CID:** 45266826 *(fills blank in brief)*

**Physical properties (web-retrieved from Chemsrc/SWGDRUG [Ref 45]):**
- **Free base:** yellowish liquid at room temperature; MW 177.24; BP ~280°C at 760 mmHg
- **Hydrochloride salt:** white to off-white crystalline powder; MP ~249.6°C
- **Density:** ~0.987 g/cm³ (free base calculated)
- **Water solubility:** High in HCl salt form (enables oral, intranasal, and intravenous administration)

**Synonyms and street names:** 4-methylmethcathinone (4-MMC), 4-methyl-N-methylcathinone, drone, M-CAT, meow meow, miaow miaow, bubble, MMCAT. Also historically marketed under "bath salts" and "plant food" labels in the UK.

**Note on brief data:** The brief had blank SMILES, molecular formula, molecular weight, InChIKey, and PubChem CID fields. All have been filled via PubChem lookup (CID confirmed) and web-retrieved sources.

---

## Pharmacology

### Mechanism of Action

Mephedrone (4-MMC) is a β-keto amphetamine of the substituted cathinone class. It acts as a **non-selective substrate (releaser) at all three plasma membrane monoamine transporters** — the dopamine transporter (DAT), norepinephrine transporter (NET), and serotonin transporter (SERT) — causing carrier-mediated efflux (reverse transport) of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) (Baumann et al. 2012 [Ref 2]; Simmler et al. 2012 [Ref 19]).

The most recent and mechanistically detailed study (Mayer et al. 2023 [Ref 1]) establishes an important distinction: **mephedrone acts as a full substrate at human SERT but as only a partial substrate at human DAT**. Specifically, it shows greater efficacy as a releaser at hSERT than at hDAT compared to fully efficacious releasing agents (S(+)-amphetamine at DAT, para-chloroamphetamine at SERT). This release is sensitive to the protein kinase C inhibitor GF109203X, confirming carrier-mediated mechanism. Mephedrone is actively transported by both hDAT and hSERT.

**Key pharmacological profile points:**
- Mephedrone is NOT a trace amine-associated receptor 1 (TAAR1) agonist, unlike classical amphetamines — this distinguishes its pharmacological fingerprint (Simmler et al. 2012 [Ref 19])
- Exhibits high blood-brain barrier permeability in vitro (among highest of all tested cathinones) (Simmler et al. 2012 [Ref 19])
- Can also induce monoamine release via OCT3 (organic cation transporter 3) when DAT is blocked, potentially explaining potentiation with MDPV (Mayer et al. 2019 [Ref 5])
- Does not directly affect major cardiac voltage-dependent ion channels at concentrations up to 30 μM (Meng et al. 2012 [Ref 29])

### Receptor Binding and Transporter Activity

In vitro characterization (Simmler et al. 2012 [Ref 19], HEK293 transfected cells):
- Mephedrone inhibits DA, NA, and 5-HT uptake with roughly **equal potency** at all three transporters (non-selective)
- Also induces 5-HT **efflux** (release), analogous to MDMA's entactogenic mechanism
- Classified in the "MDMA-like" group of cathinones: DAT/NET/SERT inhibitor + SERT releaser

Comparative neuropharmacology studies (Baumann et al. 2012 [Ref 2], rat brain synaptosomes):
- Mephedrone and methylone show profiles comparable to MDMA: nonselective substrates for plasma membrane monoamine transporters
- Both are structurally β-keto analogs of MDMA; weaker motor stimulants than methamphetamine

López-Arnau et al. 2012 [Ref 26] (comparative cathinones, rat brain):
- Mephedrone-induced hyperlocomotion was **dependent on endogenous 5-HT** (serotonin-mediated)
- Vesicular content plays a key role in mephedrone's 5-HT uptake inhibition
- Noradrenaline uptake inhibition potency suggests significant sympathetic effects

Baumann et al. 2018 [Ref 4] (comprehensive review):
- Ring-substituted cathinones like mephedrone are **transporter substrates** (releasers), contrasting with pyrrolidine-containing cathinones (e.g., MDPV) which are **non-transported inhibitors** (blockers)
- All synthetic cathinones increase extracellular monoamine concentrations, enhancing synaptic monoamine signaling

### In Vivo Neurochemical Effects

Kehr et al. 2011 [Ref 25] (awake rat nucleus accumbens microdialysis, 3 mg/kg s.c.):
- **Dopamine:** raised to **496%** of baseline; t½ for elimination ~25 min
- **Serotonin:** raised to **941%** of baseline; t½ for elimination ~26 min
- Comparison: MDMA (3 mg/kg) raised DA to 235%, 5-HT to 911%; amphetamine (1 mg/kg) raised DA to 412%, 5-HT to only 165%
- Mephedrone shows combined MDMA-like serotonergic AND amphetamine-like rapid dopaminergic release with fast elimination — a profile that may explain its potent reinforcing properties and compulsive redosing patterns

Baumann et al. 2012 [Ref 2] (rat nucleus accumbens, i.v. 0.3–1.0 mg/kg):
- Dose-related increases in extracellular DA and 5-HT; 5-HT effect proportionally greater
- Repeated dosing (3.0 and 10.0 mg/kg s.c., ×3) caused hyperthermia but no long-term change in cortical/striatal amines (unlike MDMA which depletes 5-HT)

### Neurotoxicity

Hadlock et al. 2011 [Ref 9] (rat binge model, 4×10 or 25 mg/kg s.c., 2-h intervals):
- Caused **rapid decrease in striatal DAT and hippocampal SERT function**
- Like MDMA but unlike methamphetamine: produced **persistent serotonergic but not dopaminergic deficits**
- Self-administered by rodents (abuse liability confirmed)

Angoa-Pérez et al. 2017 [Ref 6] (review):
- Mephedrone at high/repeated doses can induce neuroinflammation, oxidative stress, temperature alterations, and dysregulation of monoamine systems in animal models
- Neurotoxic gauges similar to MDMA analogs

Den Hollander et al. 2013 [Ref 32]; 2014 [Ref 33]:
- Long-term neurochemical and behavioral changes in mice after repeated exposure
- MEMRI imaging revealed differential neuroadaptation compared to methamphetamine

**Caveat:** All neurotoxicity data are from animal (rodent) models. No controlled human neuroimaging studies of long-term mephedrone-induced neurotoxicity have been published.

---

## Pharmacokinetics

### Human Data (Oral Route)

**Olesti et al. 2017 [Ref 15]** (n=6 healthy males, 150 mg oral):
- Cmax = 122.6 ± 32.9 ng/mL
- Tmax = 1.0 hour (range 0.5–2h)
- Elimination t½ = 2.2 hours
- <15% of dose excreted as free (unchanged) mephedrone in urine
- Significant inter-subject variability in plasma concentrations

**Papaseit et al. 2016 [Ref 12]** (n=12 males, 200 mg oral, RCT NCT02232789):
- Tmax = 1.25 hours
- Elimination t½ = 2.15 hours
- Comparison: MDMA 100 mg had Tmax = 2.00h, t½ = 7.89h

**Olesti et al. 2019 [Ref 13]** (dose-response 50–200 mg oral, Phase I RCT):
- **Linear pharmacokinetics** confirmed across 50–200 mg dose range
- Plasma concentrations, cardiovascular/subjective effects, and blood serotonin concentrations all correlated in dose-dependent manner

### Human Data (Intranasal Route)

**Czerwinska et al. 2021 [Ref 24]** (n=6 healthy males, 100 mg insufflated):
- Mean Tmax = 52.5 ± 20.7 min in plasma; 55.0 ± 18.2 min in whole blood
- Mean t½ = 1.98 ± 0.30 h (plasma); 2.12 ± 0.33 h (whole blood)
- Whole blood:plasma distribution ratios: mephedrone 1.11, DHM 1.30, NOR 0.765
- Mephedrone and NOR detectable on Day 2 in some participants

**Papaseit et al. 2021 [Ref 28]** (observational, oral 150 mg vs. intranasal 70 mg, n=10):
- Both routes increase euphoria, well-being, and cardiovascular effects
- Intranasal route produces **higher mephedrone concentrations in oral fluid and urine per mg dose** compared to oral — suggesting greater bioavailability via intranasal route

### Metabolism

**Primary metabolic enzyme: CYP2D6** — confirmed in vitro (Pedersen et al. 2013 [Ref 31]) and in vivo in humans (Olesti et al. 2019 [Ref 13]).

**Identified metabolites** (Olesti et al. 2017 [Ref 30]; Czerwinska et al. 2021 [Ref 24]; Pedersen et al. 2013 [Ref 31]):
1. **4'-carboxy-mephedrone (4-CARBOXY)** — most abundant metabolite in plasma and urine; approximately 10× mephedrone in urine
2. **nor-mephedrone (NOR)** — second most abundant; secondary demethylation product
3. **dihydro-mephedrone (DHM)** — ~10% of mephedrone in plasma
4. **N-succinyl-nor-mephedrone** — longest half-life: **8.2 hours** (clinical detection window)
5. **hydroxytolyl-mephedrone (HYDROXY)** — identified in forensic cases
6. **4-carboxy-dihydro-mephedrone** — identified in forensic cases

**Active CNS metabolites:** Mephedrone and nor-mephedrone cross the blood-brain barrier in vivo in rats (Olesti et al. 2017 [Ref 30]).

**Clinical pharmacogenomics flag:** Individuals with no or low CYP2D6 functionality (poor/intermediate metabolizers) accumulate higher plasma mephedrone concentrations and face elevated risk of acute toxicity (Olesti et al. 2019 [Ref 13]).

### Animal PK Data

Aarde et al. 2013 [Ref 20] (rats): t½ ~1 hour in vivo in rat plasma; ~90 minutes in liver microsomal assays. Note: rat t½ is considerably shorter than human t½ ~2h.

---

## History

### First Synthesis (1929)

Mephedrone was first synthesized in **1929** by **Saem de Burnaga Sanchez**, published in the *Bulletin de la Société Chimique de France* under the name "toluyl-alpha-monomethylaminoethylcetone." The synthesis involved α-bromination of 1-tolylpropan-1-one followed by reaction with methylamine to produce racemic 4-methylmethcathinone. The compound remained a laboratory curiosity for over seven decades — no psychoactive properties were investigated or reported at the time [Ref 44].

### Rediscovery and Market Emergence

In **2003**, an anonymous chemist using the pseudonym "Kinetic" published the synthesis of mephedrone on *The Hive*, one of the earliest online forums for recreational chemistry. This constitutes the first modern publication of mephedrone's synthesis [Ref 44].

By **2007**, mephedrone was commercially available, primarily through Israeli head shops and early internet vendors. It was first banned in **Israel in December 2007**. By 2008, law enforcement agencies in the UK and Europe were becoming aware of the substance, with **Denmark and Sweden banning it in December 2008**.

Between **2009 and 2010**, mephedrone experienced explosive growth in the United Kingdom, marketed as "plant food," "bath salts," or "research chemicals" to circumvent drug laws. It became one of the most popular recreational drugs in the UK, particularly at festivals and nightclubs (Schifano et al. 2011 [Ref 8]).

### Regulatory History

| Jurisdiction | Date | Action |
|---|---|---|
| Israel | December 2007 | First national ban |
| Denmark | December 15, 2008 | Controlled substance |
| Sweden | December 15, 2008 | Controlled substance |
| Germany | January 22, 2010 | Narcotics law amendment |
| Romania | February 2010 | Controlled |
| Netherlands | March 2010 | Controlled |
| Belgium | April 29, 2010 | Controlled |
| **United Kingdom** | **April 16, 2010** | **Class B, Misuse of Drugs Act** |
| France | June 2010 | Narcotics list |
| Russia/China | August–September 2010 | Controlled |
| European Union | October 2010 | EU-wide criminal law measures |
| **United States** | **October 2011** | **DEA emergency Schedule I (temporary)** |
| **United States** | **July 9, 2012** | **Permanent Schedule I (Synthetic Drug Abuse Prevention Act 2012)** |
| Australia | By 2010 | Illegal for human consumption; major seizures 2008, 2010 |
| India | 2014–2015 | Controlled |

Source: Erowid Legal Status Database [Ref 37]; DEA press releases.

---

## Subjective Effects

### Published Data from Controlled Human Studies

**Papaseit et al. 2016 [Ref 12]** (NCT02232789, 12 male volunteers, single oral dose 200 mg, double-blind crossover RCT vs. MDMA 100 mg and placebo):

*Physiological effects:*
- Significant increases in **systolic and diastolic blood pressure**, **heart rate**, and **pupillary diameter**
- Earlier onset and shorter duration than MDMA

*Subjective effects:*
- **Stimulant-like effects** (energy, alertness, wakefulness)
- **Euphoria and well-being** comparable to MDMA ratings
- Mild changes in perceptions (minor perceptual distortions)
- Similar overall subjective profile to MDMA, but effects peaked earlier and were shorter in duration

*PK/PD relationship:*
- Earlier Tmax (1.25h vs 2.00h for MDMA) with shorter t½ (2.15h vs 7.89h for MDMA) — the shorter PK profile may drive more compulsive redosing patterns

**Papaseit et al. 2019 [Ref 14]** (NCT02294266, mephedrone 200 mg + alcohol 0.8 g/kg):
- Combination produced **more intense euphoria and well-being** than either drug alone
- Mephedrone **reduced sedative effects** of alcohol
- Combined cardiovascular effects amplified
- Abuse liability greater for combination than mephedrone alone

**Papaseit et al. 2021 [Ref 28]** (observational, oral vs. intranasal, n=10):
- Both routes increase euphoria, well-being, and cardiovascular measures
- No statistically significant difference in subjective effects between routes at observed doses (oral 150 mg vs. intranasal 70 mg)

### Community Survey Data

**Winstock et al. 2011 [Ref 17]** (large community survey, Addiction):
- Assessed use patterns, subjective effects, and dependence liability with corroborative urine toxicology
- Reported high rates of compulsive redosing
- Effects described: euphoria, stimulation, empathy enhancement, sociability

**Uosukainen et al. 2015 [Ref 34]** (Global Drug Survey cohort, self-reported dependence):
- Compared self-reported dependence symptoms for mephedrone vs. MDMA, cocaine, ketamine
- Mephedrone showed notable dependence liability in this non-treatment-seeking sample

### Duration Data from Literature

Based on human studies (Papaseit 2016 [Ref 12], Olesti 2017 [Ref 15], Czerwinska 2021 [Ref 24]):
- **Oral:** Onset 15–45 min (based on Tmax ~1h); peak effects ~1–2h; total duration consistent with 3–6h timeframe given short t½ (~2.2h) and clinical observations
- **Insufflated:** Faster onset (Tmax ~52 min); somewhat shorter peak
- The brief's existing duration data is broadly consistent with the pharmacokinetics. No controlled studies have formally measured duration-to-offset; the brief values appear reasonable from PK parameters and observational data.

### Effects Taxonomy Notes

The effects listed in the brief span stimulant and entactogen categories consistent with the dual DA/5-HT releasing mechanism:
- **Stimulant cluster** (DA/NE-mediated): stimulation, wakefulness, motivation enhancement, thought acceleration, sexual arousal enhancement, abnormal heartbeat, vasoconstriction
- **Entactogen cluster** (5-HT-mediated): empathy enhancement, music enhancement, touch enhancement, emotional warmth
- **Compulsive redosing** is documented empirically: Winstock 2011 [Ref 17]; mechanistic basis in rapid DA release/elimination (Kehr 2011 [Ref 25])
- **Olfactory hallucination** as a listed effect: Reported by users colloquially as "fish" smell — mechanism unclear; may be related to nor-mephedrone metabolite characteristics rather than true hallucination. Not documented in controlled studies; this specific effect is based on user reports only.

---

## Safety & Toxicity

### Acute Toxicity and Overdose

**No published human LD50 data exist for mephedrone.** The exact lethal dose in humans is unknown. The brief correctly notes this [FLAG: safety-critical value unconfirmed].

**Documented adverse effects in clinical/forensic contexts:**

*Sympathomimetic toxidrome* (Wood et al. 2010 [Ref 10]; Imam et al. 2013 [Ref 46]):
- Tachycardia, hypertension, chest pain
- Hyperthermia (in human clinical reports — contrast with rat models where hypothermia was observed at standard lab temperatures)
- Diaphoresis, agitation, psychomotor agitation
- Palpitations, pupillary dilation

*Serotonin syndrome* (Garrett & Sweeney 2010 [Ref 41], BMJ Case Report):
- 22-year-old male, presented to emergency department after mephedrone ingestion
- Features: tachycardia, diaphoresis, hypertonia, hyperreflexia, **clonus**, hyperthermia
- Progressive deterioration over first hour
- Managed with appropriate serotonin syndrome treatment; sustained recovery over 15 hours
- This case establishes mephedrone alone can cause serotonin syndrome at recreational doses

*Cardiovascular effects* (Meng et al. 2012 [Ref 29], rat telemetry; Chojnacki et al. 2023 [Ref 27]):
- Dose-dependent increases in heart rate, blood pressure, and cardiac output/ejection fraction
- No direct pro-arrhythmic effect on cardiac ion channels up to 30 μM (in vitro patch clamp)
- Effects persist after reserpine pretreatment — consistent with direct transporter mechanism rather than indirect catecholamine release
- Miller et al. 2013 [Ref 39]: Ambient temperature modulates cardiac and thermoregulatory effects significantly — relevant to rave/club environment risk

### Fatality Data

**Dickson et al. 2010 [Ref 7]** (first published mephedrone fatality case report):
- 22-year-old male; blood mephedrone 0.50 mg/L; concurrent heroin (morphine 0.06 mg/L blood)
- Cause of death: multiple-drug toxicity; mephedrone contribution could not be minimized at 0.50 mg/L

**Elliott & Evans 2014 [Ref 23]** (3-year casework review, UK, 2010–2012):
- Mephedrone was the **most frequently detected NPS** in forensic casework
- 84% of cases involved co-use of other substances or alcohol
- In drug-related fatalities, only 7% solely involved NPS; 41% of cathinone-related fatalities were hangings or other mechanical suicides

**Busardò et al. 2015 [Ref 11]** (systematic review of mephedrone-specific fatalities):
- Many early media reports attributed to mephedrone were found on analytical review to involve other substances
- Only a small number of fatalities had mephedrone confirmed as causative agent (as opposed to merely detected)

**Tyler et al. 2025 [Ref 36]** (chemsex-related deaths, UK, 2017–2022):
- 21 deaths in chemsex context; mephedrone was a key drug detected
- Provides contemporary forensic toxicology data on chemsex-associated mephedrone fatalities

**Forensic blood concentrations** (Pedersen et al. 2013 [Ref 31], traffic cases):
- Blood mephedrone: 1–51 μg/kg across 4 forensic traffic cases

### Thermoregulation

There is an apparent discrepancy between animal model data and human clinical observations:
- **Rat models:** Mephedrone consistently produces **hypothermia** at typical laboratory ambient temperatures (23°C) in Wistar rats (Shortall et al. 2013 [Ref 21]; Wright et al. 2012 [Ref 22]; Aarde et al. 2013 [Ref 20])
- **Human clinical reports:** Hyperthermia is documented in overdose/toxidrome cases
- **Resolution:** Miller et al. 2013 [Ref 39] demonstrated that **ambient temperature is a critical modifier** — higher ambient temperatures shift the thermoregulatory response. In hot club environments this likely produces hyperthermia; in controlled lab settings it causes hypothermia. Muskiewicz et al. 2020 [Ref 40] confirmed cathinones show less lethality via temperature dysregulation than MDMA or methamphetamine in rodent models.

### Psychological Risks

- Psychiatric symptoms including **paranoia, hallucinations, and anxiety** documented at high doses or after prolonged use (Angoa-Pérez et al. 2017 [Ref 6]; Weinstein et al. 2017)
- Case report of psychosis and shared delusional beliefs in mephedrone/bath salts users (Springs 2015)
- Luethi & Liechti 2020 [Ref 43]: cathinone intoxication can present with acute psychiatric symptoms indistinguishable from primary psychosis in emergency settings

---

## Harm Reduction

### Route-Specific Risks

**Insufflation:**
- Rapid onset increases compulsive redosing risk (shorter time to peak effect)
- Intranasal route produces higher concentration per mg dose (Papaseit 2021 [Ref 28])
- Nasal mucosal irritation expected given cathinone chemistry, though specific mephedrone nasal damage studies were not identified in published literature [FLAG: no primary data found]

**Oral:**
- Slower onset; longer total duration; potentially lower redosing compulsion per session
- Linear dose-response at 50–200 mg (Olesti 2019 [Ref 13]) allows more predictable titration

**Intravenous:**
- Dramatically increases bioavailability and CNS exposure
- No controlled IV human data exist; associated with highest risk profile

### Contraindications

Based on published literature — no formal contraindication list exists for mephedrone. Evidence-based risk factors for serious adverse outcomes:
- **CYP2D6 poor/intermediate metabolizers:** Elevated plasma exposure → higher toxicity risk (Olesti 2019 [Ref 13]) [FLAG: safety-critical, clinically relevant]
- **Pre-existing cardiovascular disease:** Mephedrone reliably increases HR, BP, cardiac output; no safe lower bound established
- **Concurrent serotonergic drugs** (SSRIs, SNRIs, MAOIs, tramadol, lithium, triptans): Serotonin syndrome risk demonstrated for mephedrone alone (Garrett 2010 [Ref 41]); combination with other serotonergic agents substantially elevates this risk
- **Hot/warm environments (raves, clubs):** Thermoregulatory risk shifts from hypothermia to hyperthermia (Miller 2013 [Ref 39])
- **Alcohol co-use:** Amplified cardiovascular and euphoric effects with greater abuse liability (Papaseit 2019 [Ref 14])

### Emergency Response

- **Serotonin syndrome:** Managed with supportive care, benzodiazepines for agitation, cyproheptadine where appropriate; physical cooling for hyperthermia. Full recovery possible with appropriate treatment (Garrett 2010 [Ref 41])
- **Sympathomimetic toxidrome:** Supportive; benzodiazepines for agitation; avoid beta-blockers without alpha-blocker cover (unopposed alpha agonism risk)
- **Cardiovascular:** ECG monitoring; hypertension management
- No specific antidote

### Testing and Identification

No primary published data on mephedrone-specific reagent tests (Marquis, Simon's, etc.) were found in the indexed literature for this research output [FLAG: gap in harm reduction data]. Analytical identification methods are well-established via GC-MS and LC-MS/MS (Pedersen 2013 [Ref 31]; Olesti 2017 [Ref 30]).

---

## Tolerance & Dependence

### Preclinical Evidence

**Self-administration in rodents** (Aarde et al. 2013 [Ref 20]; Hadlock et al. 2011 [Ref 9]):
- Mephedrone reliably maintained self-administration in rats at 0.5 and 1.0 mg/kg/infusion
- Dose-substitution studies confirm dose-dependent reinforcing properties
- Progressive ratio breakpoints confirm motivational salience

**Stereochemistry and reward** (Philogene-Khalid et al. 2017 [Ref 16]):
- **R-enantiomer** primarily responsible for rewarding, reinforcing, and motivational properties
- R-MEPH showed higher break points under progressive ratio vs. S-MEPH
- R-MEPH elicited greater positive affect (50 kHz ultrasonic vocalizations) in rats
- Sold commercially as racemate; the S-enantiomer contributes less to abuse liability

**Brain stimulation reward** (Bonano et al. 2014 [Ref 35]):
- Mephedrone dose-dependently facilitated intracranial self-stimulation in rats — consistent with abuse liability

### Human Evidence

**Winstock et al. 2011 [Ref 17]** (Addiction):
- Survey documented compulsive redosing and difficulty stopping during a session
- Dependence features reported by a subset of regular users
- Urine toxicology corroborated self-reported use patterns

**Uosukainen et al. 2015 [Ref 34]**:
- Self-reported last-year dependence symptoms for mephedrone compared to MDMA, cocaine, and ketamine in a large recreational poly-drug user sample

### Long-Term Effects

**Den Hollander et al. 2013 [Ref 32]** (mice, repeated exposure):
- Behavioral and neurochemical changes persisted after discontinuation
- Changes included alterations in anxiety-related behavior and monoamine system markers

**Hadlock et al. 2011 [Ref 9]** (rat binge model):
- Persistent serotonergic deficits (decreased hippocampal SERT function) after binge exposure — similar to MDMA profile but without dopaminergic deficits

### Tolerance Data from Brief

The brief lists: tolerance buildup with prolonged use; half-life 5 days; full reset 1.5 weeks; cross-tolerances: dopamine, stimulant. **No specific published primary source was identified for these values.** These appear to originate from the Psychonaut Wiki community synthesis or prior editorial entry. The cross-tolerance to dopaminergic and stimulant drugs is pharmacologically plausible given the mechanism, but the specific 5-day half-life and 1.5-week reset timeframes are **not confirmed by published research** [FLAG: safety-relevant values not verified against primary source].

---

## Interactions

### Alcohol (Controlled Human Data)

**Papaseit et al. 2019 [Ref 14]** (NCT02294266, RCT, n=11 males, 200 mg mephedrone + 0.8 g/kg ethanol):
- Combination produced **greater euphoria and well-being** than either drug alone
- Mephedrone **attenuated sedative effects** of alcohol — potentially masking alcohol intoxication levels
- **Amplified cardiovascular effects** (blood pressure, heart rate) relative to either drug alone
- Greater combined abuse liability
- PK: no significant pharmacokinetic interaction detected at these doses
- **Clinical significance:** High interaction — the combination is commonly used in recreational settings [Ref 14]

### Heroin / Opioids

**Dickson et al. 2010 [Ref 7]:**
- Fatal combination; blood mephedrone 0.50 mg/L with morphine 0.06 mg/L
- Mechanism: combined CNS stimulant + opioid respiratory depressant; cardiovascular interaction

### Tramadol (Listed as "Lethal" in Brief)

**No specific published case report of a mephedrone + tramadol fatality was identified in indexed literature.** The interaction labeled "lethal" in the brief appears to be based on class-level pharmacological reasoning rather than a specific documented case.

**Mechanistic basis:** Tramadol inhibits serotonin and norepinephrine reuptake and has weak serotonin-releasing properties. Combined with mephedrone (a potent serotonin releaser), the resulting serotonergic excess creates substantial risk for **serotonin syndrome**. The case report by Garrett & Sweeney (2010 [Ref 41]) establishes that mephedrone alone can cause serotonin syndrome. Tramadol is independently a known serotonin syndrome precipitant. The combination must be considered dangerous.

**[FLAG: The "lethal" classification in the brief is pharmacologically well-supported but lacks a specific published mephedrone+tramadol case report. The generation agent should classify this interaction as dangerous/potentially lethal based on serotonergic mechanism, noting the absence of a direct case report while citing the mechanistic evidence.]**

### MDMA

Both drugs raise synaptic 5-HT substantially; co-administration risks serotonin syndrome. No controlled human study exists for this combination. The brief lists this as "dangerous" — this is pharmacologically well-supported [Ref 1] [Ref 2].

### MDPV

**Mayer et al. 2019 [Ref 5]:** MDPV (a DAT/NET blocker) blocks conventional mephedrone-induced DA release via DAT, but mephedrone can still induce monoamine release via OCT3 when DAT is occupied. The combination may produce paradoxically potent and unpredictable psychostimulant effects — not simple additive but complex pharmacodynamic interaction.

### Cardiovascular Drugs

No specific published drug-drug interaction studies for cardiovascular medications (beta-blockers, antihypertensives) and mephedrone. Given mephedrone's reliable increases in HR and BP (Meng 2012 [Ref 29]; Chojnacki 2023 [Ref 27]), patients on antihypertensive therapy may experience unpredictable cardiovascular effects.

### MAOIs

No published data on mephedrone-MAOI combinations found. Given the mechanism (massive monoamine release), MAOIs would be expected to dramatically potentiate and prolong mephedrone's effects with life-threatening serotonergic and adrenergic risk. **This is a significant gap [FLAG].**

---

## Legal Status

| Jurisdiction | Status | Date | Notes |
|---|---|---|---|
| United Kingdom | Class B | April 16, 2010 | Misuse of Drugs Act; criminal penalties for possession, supply |
| United States | Schedule I | July 9, 2012 | Synthetic Drug Abuse Prevention Act of 2012; DEA temp scheduling Oct 2011 |
| European Union | Criminal law measures | October 2010 | EU-wide; implemented by member states individually |
| Denmark | Controlled | December 15, 2008 | Among first bans globally |
| Sweden | Controlled | December 15, 2008 | Among first bans globally |
| Germany | Controlled | January 22, 2010 | Narcotics Act amendment |
| Netherlands | Controlled | March 2010 | |
| Belgium | Controlled | April 29, 2010 | |
| France | Narcotic | June 2010 | |
| Israel | Controlled | December 2007 | First national ban globally |
| Australia | Illegal | By 2010 | Illegal for human consumption; Therapeutic Goods Act |
| Canada | Schedule I | 2012 | CDSA scheduling |

Source: Erowid Legal Status Database [Ref 37].

**Note on brief characterization ("emerging"):** While mephedrone is characterized as "emerging" in the brief's characterization field, it has been scheduled in all major Western jurisdictions since 2010–2012. The "emerging" tag likely refers to its status as a synthetic cathinone NPS rather than its current legal or market status. In the UK/Europe it is now an established controlled substance with an extensive published literature.

---

## Clinical Trials

**NCT02232789:** "Abuse Liability and Human Pharmacology of Mephedrone"
- Status: COMPLETED
- Phase: 1
- Sponsor: Parc de Salut Mar (Barcelona, Spain)
- Conditions: Amphetamine-Related Disorders
- Published output: Papaseit et al. 2016, *Neuropsychopharmacology* [Ref 12] — randomized double-blind crossover RCT, 12 males, single oral dose 200 mg mephedrone vs. 100 mg MDMA vs. placebo

**NCT02294266:** "Mephedrone and Alcohol Interactions in Humans"
- Status: COMPLETED
- Phase: 1
- Sponsor: Parc de Salut Mar (Barcelona, Spain)
- Conditions: Amphetamine-Related Disorders; Alcohol-Related Disorders
- Published output: Papaseit et al. 2019, *Frontiers in Pharmacology* [Ref 14] — double-blind crossover RCT, 11 males, 4 conditions (mephedrone+alcohol, mephedrone alone, alcohol alone, placebo)

No active or recruiting trials for mephedrone were identified as of April 2026.

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## Community Feedback Analysis

No community feedback was submitted in Part A2 of the brief.

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## Gaps & Flags

### 🚩 Safety-Critical Values Not Confirmed

1. **Exact lethal dose / LD50 in humans:** Not published. Toxic dose range entirely unknown. Brief correctly notes this.
2. **Tramadol interaction classified as "lethal":** No specific mephedrone+tramadol case report found in indexed literature. Danger classification is pharmacologically sound (both serotonergic → serotonin syndrome) but is based on class mechanism, not a primary case report. **Generation agent should document this gap explicitly and cite the mechanistic basis.**
3. **Tolerance half-life (5 days) and full reset (1.5 weeks):** Not confirmed against any published primary source. Appears to be community-derived data. Label as unverified/community consensus in the article.
4. **Dose sensitivity field:** The brief has this blank. No published human dose-finding study specifically characterized dose sensitivity beyond the clinical trials at 50–200 mg oral. Published dose data suggest the brief's listed ranges (insufflated 5–125+ mg; oral 15–300+ mg) are plausible but no systematic threshold study exists.

### 🔍 Data Absent from Literature

5. **Mephedrone-MAOI interaction:** No published data found. High-risk mechanism; must flag as contraindicated based on class reasoning.
6. **Nasal damage specific to mephedrone insufflation:** No primary studies found. General cathinone-related nasal irritation expected but undocumented.
7. **Pregnancy/reproductive safety:** No published data.
8. **Specific IC50 values (nM) at human DAT/NET/SERT:** Available in full text of Simmler 2012 [Ref 19] and Baumann 2012 [Ref 2] but were not extractable from abstracts in this research run. Full-text access would be needed to populate pharmacology tables with exact Ki/EC50 values.
9. **Mephedrone reagent testing profiles:** No published primary data on colorimetric reagent test results (Marquis, Mecke, Simon's, etc.) identified.
10. **Dependence data (formal):** No controlled human dependence/withdrawal studies published. Brief's dependence section is blank — confirm no primary data exist.

### ⚠️ Cross-Source Discrepancies

11. **Characterization tag "emerging":** Mephedrone has extensive published literature (>300 primary papers) and has been controlled since 2010–2012. The "emerging" tag may reflect classification schema rather than current status. Generation agent should address this.
12. **Physical form discrepancy:** The free base is a liquid at room temperature, not a crystalline solid. The HCl salt (most commonly encountered form) is the white crystalline powder associated with recreational use. Generation agent should clarify this in chemistry section.
13. **SMILES in brief was blank:** Filled — `Cc1ccc(cc1)C(=O)C(C)NC`. PubChem CID 45266826 confirmed.

### 📊 Structural Analogy Sections

14. **MAOI interaction risk:** Based on amphetamine/stimulant class reasoning, not mephedrone-specific data.
15. **Oral bioavailability (% absorbed):** Not directly measured in published human studies. Can be inferred from comparative plasma concentrations between oral and IV routes, but IV human data don't exist.

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*Research conducted 2026-04-20 | 48 citations in registry | 21 research steps logged*
*Provenance ID: 25618495-032d-4439-b758-e10a0e03004e*