4-MMC Mephedrone

4-Methylmethcathinone (also known as 4-MMC, M-CAT, drone, meow meow, and mephedrone[1]) is a novel entactogen-stimulant substance of the cathinone class. Mephedrone belongs to a group known as the substituted cathinone, which are derivatives of the active ingredient in the khat plant (Catha edulluis).

Mephedrone was first synthesized in 1929, but did not become widely known until it was rediscovered in 2003. By 2007, it was reported to be available for sale on the internet, by 2008 law enforcement agencies had become aware of the compound, and by 2010 it had been reported in most of Europe, becoming particularly prevalent in the United Kingdom.

It comes in the form of tablets or a powder, which users can swallow, snort, inject or insert rectally, producing effects which are somewhat similar to those of MDMA, amphetamine, and cocaine. It is reported to produce a mixture of classic stimulant and entactogenic effects effects reminiscent of cocaine and MDMA.[2]


Mephedrone, or 4-methylmethcathinone, is a synthetic molecule of the cathinone family. Cathinones are structurally similar to amphetamines, they contain a phenethylamine core featuring a phenyl ring bound to an amino (NH2) group through an ethyl chain with an additional methyl substitution at Rα. Amphetamines and cathinones are alpha-methylated phenethylamines, cathinones contain an additional carbonyl group at R1. Mephedrone contains an additional methyl substitutions at RN, similarly to MDMA and methamphetamine, and R4 of its phenyl ring.


Given its chemical structure, mephedrone is likely to act as a releasing agent and a reuptake inhibitor for monoamine neurotransmitters such as dopamine, serotonin and noradrenaline.[3]

Several articles published near the end of 2011 examined the effects of mephedrone in the brains of rats, as well as examining the reinforcing potential of mephedrone. Dopamine and serotonin were collected using microdialysis, and increases in dopamine and serotonin were measured. Mephedrone administration caused about a 500% increase in dopamine, and about a 950% increase in serotonin. They reached their peak concentrations at 40 minutes and 20 minutes and returned to baseline by 120 minutes after injection.

Analysis of the ratio for dopamine and serotonin indicated mephedrone was preferentially a serotonin releaser, with a ratio of 1.22:1 (serotonin vs. dopamine). Additionally, half-lives for the decrease in dopamine and serotonin were calculated and found to have decay rates of 24.5 minutes and 25.5 minutes.

These findings show mephedrone induces a massive increase in both dopamine and serotonin, combined with rapid clearance. This increase in neurotransmitters provides an explanation for the euphoric and stimulating subjective effects induced by this experience. The rapid rise and subsequent fall of dopamine levels could also explain some of the addictive properties of mephedrone display in some users.[4][5]

Subjective effects

The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. These effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances of inducing a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death.

Physical effects


Cognitive effects


After effects

Aftereffects (3).svg

Experience reports

There are currently no anecdotal reports which describe the effects of this compound within our experience index. Additional experience reports can be found here:

  • Erowid Experience Vaults: Mephedrone

Toxicity and harm potential

Further information: Research chemicals § Toxicity and harm potential

Almost nothing is known about the long-term effects of mephedrone due to its short history of its use.[9] Along side of this, the exact toxic dosage is unknown.[10]

In 2010, unconfirmed reports speculated about the role mephedrone has played in the deaths of several young people in the UK. By July 2010, mephedrone had been alleged to be involved in 52 fatalities in the UK, but detected in only 38 of these cases. Of the nine that coroners had finished investigating, two were caused directly by mephedrone.[11] The first death reported to be caused by mephedrone use was that of 46-year-old[12]who had underlying health problems and repeatedly injected the drug.[13] A report in Forensic Science International in stated mephedrone intoxication has been recorded as the cause of death in two cases in Scotland.[14]

Despite similarities to known neurotoxins such as methamphetamine and other cathinone derivatives, mephedrone does not appear to produce neurotoxic effects in the dopamine system of mice.[15]

It is strongly recommended that one use harm reduction practices when using this drug.

Tolerance and addiction potential

As with other stimulants, the chronic use of mephedrone can be considered moderately addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal effects may occur if a person suddenly stops their usage.

Tolerance to many of the effects of mephedrone develops with prolonged and repeated use. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 – 7 days for the tolerance to be reduced to half and 1 – 2 weeks to be back at baseline (in the absence of further consumption). Mephedrone presents cross-tolerance with all dopaminergic stimulants, meaning that after the consumption of mephedrone all stimulants will have a reduced effect.

Dangerous interactions

Although many psychoactive substances are reasonably safe to use on their own, they can quickly become dangerous or even life-threatening when taken with other substances. The following lists some known dangerous combinations, but cannot be guaranteed to include all of them. Independent research should always be conducted to ensure that a combination of two or more substances is safe to consume. Some interactions listed have been sourced from Tripsit.

  • MDMA – The neurotoxic effects of MDMA may be increased when combined with other amphetamines.
  • Cocaine – This combination may increase strain on the heart.
  • Stimulants – Mephedrone can be potentially dangerous in combination with other stimulants as it can increase one’s heart rate and blood pressure to dangerous levels.
  • 25x-NBOMe & 25x-NBOH – Members of the 25x family are highly stimulating and physically straining. Combinations with stimulants should be avoided due to the risk of excessive stimulation. This can result in panic attacks, thought loops, seizures, increased blood pressure, vasoconstriction, and heart failure in extreme cases.
  • Alcohol – Alcohol can be dangerous to combine with stimulants due to the risk of accidental over-intoxication. Stimulants mask the sedative effects of alcohol, which is the main factor people use to assess their degree of intoxication. Once the stimulant wears off, the depressant effects of alcohol are left unopposed, which can result in blackouts and respiratory depression. If combined, one should strictly limit themselves to only drinking a certain amount of alcohol per hour.
  • DXM – Combinations with DXM should be strictly avoided due to DXM’s effects on serotonin and dopamine reuptake. This can lead to panic attacks, hypertensive crisis, or serotonin syndrome.
  • MXE – Combinations with MXE may dangerously elevate blood pressure and increase the risk of psychosis.
  • Tramadol – Tramadol lowers the seizure threshold.[16] Combinations with stimulants may further increase this risk.
  • MDMA – The neurotoxic effects of MDMA may be increased when combined with other stimulants.
  • Cocaine – This combination may increase strain on the heart.

Serotonin syndrome risk

Combinations with the following substances can cause dangerously high serotonin levels. Serotonin syndrome requires immediate medical attention and can be fatal if left untreated.

  • MAOIs such as syrian ruebanisteriopsis caapi2C-T-7αMTphenelzineselegiline, and moclobemide[17]
  • Serotonin releasers such as MDMA4-FAmethamphetaminemethylone and αMT
  • Selective serotonin re-uptake inhibitors (SSRIs)
  • Serotonin-norepinephrine reuptake inhibitors (SNRIs) such as tramadol and DXM
  • 5-HTP

Legal issues

  • European Union (EU): In October 2010, a European Union commission called for an EU-wide ban of mephedrone.[18]
  • Australia: Mephedrone has been added to the Australian federal drug watch list and is now considered illegal if intended for human consumption.
  • Austria: Mephedrone is illegal to possess, produce and sell under the SMG (Suchtmittelgesetz Österreich).
  • Belgium: Mephedrone was banned on April 29, 2010, by making it a regulated drug requiring the approval of the Ministry of Human Health to import, sell, or possess.
  • Brazil: Mephedrone was added to the list of Scheduled drugs (class F2), making it illegal to possess, sell, or manufacture without a license as of August 2011.[19]
  • China: Mephedrone was made a Category I psychotropic substance, making it illegal to sell, buy, import, export, and manufacture as of September 2010.
  • Denmark: Denmark’s Minister for Health and Prevention Jakob Axel Nielsen banned mephedrone, flephedrone and ethylcathinone on December 18, 2008. As of July 1, 2012, Denmark also created a type of analogue law that would include cathinones like mephedrone[20]
  • Finland: Through the Medicines Act, mephedrone is classified as a “medicinal product”, making it illegal to manufacture, import, possess, sell, or transfer it without a prescription.
  • France: French Ministry of Health decided in early June 2010 to add mephedrone to the list of illicit substances in the “Journal Officiel du 11 juin 2010”.[21]
  • Germany: Mephedrone was added to BtMG Anlage I, making it illegal to manufacture, import, possess, sell, or transfer it without a license as of January 22, 2010.[22]
  • Israel: In December 2007, mephedrone was added to Israel’s list of controlled substances, making it illegal to buy, sell, or possess.[23]
  • Netherlands: In March, 2010, the Dutch Ministry of Health and the Medicines Authority IGZ informed the Ministry of Justice that they now consider mephedrone an unregulated medicine; sales and distribution of it are now prohibited.
  • Norway: The “Derivatbestemmelsen” is an Analog Act-type law in Norway that controls mephedrone, Bk-MBDB, Bromo-Dragonfly, 1,4butanediol, GBL, and MBDB.[24]
  • Poland: On August 25, 2010, mephedrone was added to the list of controlled “psychotropic drugs” in the I-P group.[25]
  • Romania: Mephedrone was added to Romania’s list of controlled substances in February 2010.[26]
  • Russia: Mephedrone is classified as List 1 in Russian Federation as of August 2010. This means it is illegal to manufacture, buy, possess, or distribute.[27]
  • Slovak Republic: Starting March 1, 2011 mephedrone is controlled in the Slovak Republic.[28]
  • Sweden: In Sweden, the drug is classified as a health hazard. A ban on mephedrone went into effect on December 15, 2008, making its sale illegal. Use of 4-methylmethcathinone is not explicitly illegal under this regulation.
  • United Kingdom – Mephedrone is a Class B drug in the United Kingdom as a result of the cathinone catch-all clause.[29]
  • USA: Mephedrone is currently a Schedule I drug in the United States. This means it is illegal to manufacture, buy, possess, or distribute (sell, trade or give) without a DEA license.

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