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Summary sheet: Mephedrone
Chemical Nomenclature
Common names Mephedrone, 4-MMC, Drone, M-CAT, Meow Meow
Substitutive name 4-Methylmethcathinone
Systematic name (RS)-2-Methylamino-1-(4-methylphenyl)propan-1-one
Class Membership
Psychoactive class Stimulant / Entactogen
Chemical class Cathinone
Routes of Administration

WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.

Threshold 15 mg
Light 50 - 100 mg
Common 100 - 200 mg
Strong 200 - 300 mg
Heavy 300 mg +
Total 4 - 8 hours
Onset 15 - 45 minutes
Come up 15 - 30 minutes
Peak 2 - 4 hours
Offset 30 - 90 minutes
After effects 2 - 4 hours

Threshold 5 mg
Light 15 - 45 mg
Common 45 - 80 mg
Strong 80 - 125 mg
Heavy 125 mg +
Total 3 - 6 hours
Onset 15 - 45 minutes
Come up 15 - 30 minutes
Peak 30 - 60 minutes
Offset 30 - 90 minutes
After effects 2 - 4 hours

DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.

Serotonin releasers

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 cathinones, which are derivatives of the active ingredient in the khat plant (Catha edulluis). It is thought to produce its effects by promoting the release of the neurotransmitters serotonin, dopamine, and norepinephrine in the brain.[citation needed]

Mephedrone was first synthesized in 1929, but did not become widely known until it was rediscovered in 2003. In 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.[citation needed]

Subjective effects include stimulation, anxiety suppression, disinhibition, enhanced empathy and sociability, relaxation, increased libido, and euphoria. It is reported to produce a mixture of classic stimulant and entactogenic effects reminiscent of cocaine and MDMA.[1] It comes in the form of tablets or a powder, which users can swallow, snort, inject or insert rectally. It is also sometimes sold as MDMA ("molly").

Limited data exists about the pharmacological properties, metabolism, and toxicity of mephedrone, and it has little history of human use. Preliminary evidence suggests it may possess neurotoxic and cardiotoxic properties.[citation needed] It is highly advised to use harm reduction practices if using this substance.


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.[2]

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.[3][4]

Subjective effects

Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWiki contributors. As a result, they should be viewed with a healthy degree of skepticism.

It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.

Physical effects

Cognitive effects

After effects
Aftereffects (3).svg

Experience reports

There are currently 0 experience reports which describe the effects of this substance in our experience index. Additional experience reports can be found here:

Toxicity and harm potential

Table from the 2010 ISCD study ranking various drugs (legal and illegal) based on statements by drug-harm experts. Mephedrone was found to be the 13th overall most dangerous drug.[8]

Almost nothing is known about the long-term effects of mephedrone due to its short history of its use.[5] Along side of this, the exact toxic dosage is unknown.[9]

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.[10] The first death reported to be caused by mephedrone use was that of 46-year-old[11] who had underlying health problems and repeatedly injected the drug.[12] A report in Forensic Science International in stated mephedrone intoxication has been recorded as the cause of death in two cases in Scotland.[13]

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.[14]

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 highly addictive with an extreme 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

Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).

Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.

  • 25x-NBOMe & 25x-NBOH - 25x compounds are highly stimulating and physically straining. Combinations with Mephedrone should be strictly avoided due to the risk of excessive stimulation and heart strain. This can result in increased blood pressure, vasoconstriction, panic attacks, thought loops, seizures, and heart failure in extreme cases.
  • Alcohol - Combining alcohol with stimulants can be dangerous due to the risk of accidental over-intoxication. Stimulants mask alcohol's depressant effects, which is what most people use to assess their degree of intoxication. Once the stimulant wears off, the depressant effects will be left unopposed, which can result in blackouts and severe respiratory depression. If mixing, the user should strictly limit themselves to only drinking a certain amount of alcohol per hour.
  • DXM - Combinations with DXM should be avoided due to its inhibiting effects on serotonin and norepinephrine reuptake. There is an increased risk of panic attacks and hypertensive crisis, or serotonin syndrome with serotonin releasers (MDMA, methylone, mephedrone, etc.). Monitor blood pressure carefully and avoid strenuous physical activity.
  • MDMA - Any neurotoxic effects of MDMA are likely to be increased when other stimulants are present. There is also a risk of excessive blood pressure and heart strain (cardiotoxicity).
  • MXE - Some reports suggest combinations with MXE may dangerously increase blood pressure and increase the risk of mania and psychosis.
  • Dissociatives - Both classes carry a risk of delusions, mania and psychosis, and these risk may be multiplied when combined.
  • Stimulants - Mephedrone may be dangerous to combine with other stimulants like cocaine as they can increase one's heart rate and blood pressure to dangerous levels.
  • Tramadol - Tramadol is known to lower the seizure threshold[15] and 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.

Legal status

In December 2010, the European Council decided that mephedrone shall be subjected by the Member States to control measures and criminal penalties.[17]

  • Australia: Mephedrone has been added to the Australian federal drug watch list and is now considered illegal if intended for human consumption. Mephedrone is considered a Schedule 9 prohibited substance in Australia under the Poisons Standard [18]. A Schedule 9 substance is a substance which may be abused or misused and the manufacture, possession, sale or use of is prohibited by law except when required for medical or scientific research, or for analytical, teaching or training purposes with approval of Commonwealth and/or State or Territory Health Authorities.
  • Austria: Mephedrone is illegal to possess, produce and sell under the SMG (Suchtmittelgesetz Österreich) as of August 21, 2010.[19]
  • 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.[citation needed]
  • 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.[20]
  • China: Mephedrone is a Category I psychotropic substance as of September 1, 2010.[21] It is illegal to sell, buy, import, export, and manufacture it.
  • Croatia: Mephedrone is a controlled substance as of January 12, 2010.[22]
  • 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[23]
  • Estonia: Mephedrone is a controlled substance as of November 2009.[24]
  • 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.[25]
  • 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".[26]
  • Germany: Mephedrone is controlled under Anlage I BtMG (Narcotics Act, Schedule I)[27] as of January 22, 2010.[28] It is illegal to manufacture, possess, import, export, buy, sell, procure or dispense it without a license.[29]
  • Guernsey: Mephedrone is a Class B controlled substance as of April 16, 2010.[30]
  • Hungary: Mephedrone is a List 1 controlled substance as of January 1, 2011.[31]
  • Isle of Man: It is illegal to import or sell mephedrone since February 2010.[32]
  • Ireland: Mephedrone is controlled under the Misuse of Drugs Act 1977 as of May 11, 2010.[33]
  • Israel: In December 2007, mephedrone was added to Israel's list of controlled substances, making it illegal to buy, sell, or possess.[34]
  • Italy: Mephedrone is a Tabella I controlled substance.[35]
  • Jersey: Mephedrone is a Class C controlled substance since December 2010.[36]
  • Lithuania: Mephedrone is a controlled substance as of June 20, 2010.[37]
  • Mexico: Mephedrone is a Schedule I controlled substance as of January 7, 2014.[38]
  • The 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.[citation needed]
  • Norway: The "Derivatbestemmelsen" is an Analog Act-type law in Norway that controls mephedrone, Bk-MBDB, Bromo-DragonFLY, 1,4-Butanediol, GBL, and MBDB.[39]
  • Poland: On August 25, 2010, mephedrone was added to the list of controlled "psychotropic drugs" in the I-P group.[40]
  • Romania: Mephedrone was added to Romania's list of controlled substances in February 2010.[41]
  • 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.[42]
  • Slovak Republic: Starting March 1, 2011 mephedrone is controlled in the Slovak Republic.[43]
  • Singapore: Mephedrone is a banned substance as of November 15, 2010.[44]
  • Spain: Mephedrone is a Schedule I controlled substance as of February 10, 2011.[45]
  • 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.[46]
  • Switzerland: Mephedrone is a controlled substance specifically named under Verzeichnis D.[47]
  • Turkey: Mephedrone is a classed as drug and is illegal to possess, produce, supply, or import.[48]
  • United Kingdom: Mephedrone is a Class B drug in the United Kingdom as a result of the cathinone catch-all clause.[49]
  • United States: 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.[50]

See also

External links


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  2. Winstock, A. R., Marsden, J., Mitcheson, L. (23 March 2010). "What should be done about mephedrone?". BMJ (Clinical research ed.). 340: c1605. doi:10.1136/bmj.c1605. ISSN 1756-1833. 
  3. Kehr, J., Ichinose, F., Yoshitake, S., Goiny, M., Sievertsson, T., Nyberg, F., Yoshitake, T. (December 2011). "Mephedrone, compared with MDMA (ecstasy) and amphetamine, rapidly increases both dopamine and 5-HT levels in nucleus accumbens of awake rats". British Journal of Pharmacology. 164 (8): 1949–1958. doi:10.1111/j.1476-5381.2011.01499.x. ISSN 0007-1188. 
  4. Hadlock, G. C., Webb, K. M., McFadden, L. M., Chu, P. W., Ellis, J. D., Allen, S. C., Andrenyak, D. M., Vieira-Brock, P. L., German, C. L., Conrad, K. M., Hoonakker, A. J., Gibb, J. W., Wilkins, D. G., Hanson, G. R., Fleckenstein, A. E. (November 2011). "4-Methylmethcathinone (mephedrone): neuropharmacological effects of a designer stimulant of abuse". The Journal of Pharmacology and Experimental Therapeutics. 339 (2): 530–536. doi:10.1124/jpet.111.184119. ISSN 1521-0103. 
  5. 5.0 5.1 Clubbers are “turning to new legal high mephedrone”, 2010 
  6. James, D., Adams, R. D., Spears, R., Cooper, G., Lupton, D. J., Thompson, J. P., Thomas, S. H. L., National Poisons Information Service (August 2011). "Clinical characteristics of mephedrone toxicity reported to the U.K. National Poisons Information Service". Emergency medicine journal: EMJ. 28 (8): 686–689. doi:10.1136/emj.2010.096636. ISSN 1472-0213. 
  7. Fort, H. (2015), Does your child smell of cat wee? It could be meow meow 
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  10. Ghodse, H.; Corkery, J.; Ahmed, K.; Naidoo, V.; Oyefeso and, A.; Schifano, F. (July 2010). "Drug-related deaths in the UK: Annual Report 2010". International Centre for Drug Policy, St George's University of London. p. 77. Archived from the original (PDF) on 2010-01-02. Retrieved 2010-01-02.
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  12. Teenagers’ deaths “not caused by mephedrone”, 2010, retrieved 20 September 2010 
  13. Torrance, H., Cooper, G. (10 October 2010). "The detection of mephedrone (4-methylmethcathinone) in 4 fatalities in Scotland". Forensic Science International. 202 (1–3): e62–63. doi:10.1016/j.forsciint.2010.07.014. ISSN 1872-6283. 
  14. Angoa-Pérez, M., Kane, M. J., Francescutti, D. M., Sykes, K. E., Shah, M. M., Mohammed, A. M., Thomas, D. M., Kuhn, D. M. (March 2012). "Mephedrone, an abused psychoactive component of "bath salts" and methamphetamine congener, does not cause neurotoxicity to dopamine nerve endings of the striatum". Journal of Neurochemistry. 120 (6): 1097–1107. doi:10.1111/j.1471-4159.2011.07632.x. ISSN 1471-4159. 
  15. Talaie, H.; Panahandeh, R.; Fayaznouri, M. R.; Asadi, Z.; Abdollahi, M. (2009). "Dose-independent occurrence of seizure with tramadol". Journal of Medical Toxicology. 5 (2): 63–67. doi:10.1007/BF03161089. eISSN 1937-6995. ISSN 1556-9039. OCLC 163567183. 
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  18. "Poisons Standard June 2021" (in English). May 26, 2021. 
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  21. "Mephedrone regulated as psychotropic substances". State Food and Drug Administration. Archived from the original on 15 August 2010. Retrieved December 27, 2019. 
  22. "Dopuna popisa opojnih droga, psihotropnih tvari i biljaka iz kojih se može dobiti opojna droga te tvari koje se mogu uporabiti za izradu opojnih droga" (in Croatian). Croatian Ministry of Health and Social Welfare. Retrieved December 27, 2019. 
  24. "Sotsiaalministri 27.11.2009 määrus number 87" (in Estonian). Estonian Ministry of Social Affairs. Archived from the original on September 21, 2010. Retrieved December 27, 2019. 
  25. Juha Matias Lehtonen (September 5, 2008). "Rapujuhlat saaristossa" (in Finnish). City Magazine. Retrieved December 27, 2019. 
  27. "Anlage I BtMG" (in German). Bundesministerium der Justiz und für Verbraucherschutz. Retrieved December 10, 2019. 
  28. "Vierundzwanzigste Verordnung zur Änderung betäubungsmittelrechtlicher Vorschriften" (PDF) (in German). Bundesanzeiger Verlag. Retrieved December 27, 2019. 
  29. "§ 29 BtMG" (in German). Bundesministerium der Justiz und für Verbraucherschutz. Retrieved December 10, 2019. 
  30. "Guernsey makes Mephedrone class B drug". BBC News. April 13, 2010. Retrieved December 27, 2019. 
  31. "MAGYAR KÖZLÖNY: A MAGYAR KÖZTÁRSASÁG HIVATALOS LAPJA" (PDF) (in Hungarian). Retrieved December 10, 2019. 
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  48. 17 şubat 2012, BAKANLAR KURULU KARARI Karar Sayısı : 2012/2861 |
  49. The Misuse of Drugs Act 1971 (Amendment) Order 2010