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Mephedrone (Meow Meow)

The molecular structure of Mephedrone
  • Mephedrone (4-methylmethcathinone) is a former legal-high that is now banned across the EU. It is a manufactured substance rather than natural substance.

  • It appears as a white or off-white powder which is primarily either snorted or swallowed. Injection has also been reported. Injection of drugs is associated with higher risks of overdose and other harms like infection.

  • Mephedrone is a stimulant and its effects are reported to be similar in some ways to cocaine and MDMA. As mephedrone has only been widely used from around 2009 onwards, not much has been established scientifically about the specific effects of the drug.

  • People who have used mephedrone report stimulant effects such as increased energy, self-confidence and talkativeness. Reported effects also include feelings of empathy/closeness to other people, which is why mephedrone is sometimes said to be like MDMA. However, most users report that mephedrone’s effects are noticeably different to those of MDMA, being more stimulant-like and lacking the full extent of MDMA’s sensual, empathy-promoting properties.

    When mephedrone is snorted, it only takes a few minutes for its effects to appear, and the effects generally peak in half an hour or less. When swallowed (usually wrapped in a cigarette paper) its effects can take more than 45 minutes to appear, depending on factors like how much food is in the stomach.


    Some people have unwanted side effects of the drug such as: loss of appetite, muscle clenching and tremors, headache, anxiety, elevated blood pressure and chest pain, fast/irregular heartbeat, difficulty urinating, changes in body temperature (hot flushes and sweating) and blue/cold fingers.

    People using the drug also report a comedown period after use, which can also be compared to the comedown periods experienced after cocainespeed or MDMA use. Users have reported that it is very tempting to take more mephedrone again and again to keep the high going and to prevent the comedown. This increases the risks of immediate harm and may increase the risk of becoming addicted. (Much of the information in this section was taken from Schifano et al, 2010).

  • None known.

  • There have been deaths associated with or caused by mephedrone use, although not as many as were reported in the media. Usually, deaths involved very high doses, mephedrone use with alcohol and other drugs (including interacting prescription drugs) or pre-existing problems such as heart or liver conditions.

    Mephedrone deaths and serious emergencies occur in a similar way to deaths from other strong stimulants. The drug effects can overload the heart, and overheating can cause seizures and organ failure. Fatal accidents have also been associated with the drug.

    It should always be treated as a medical emergency if someone collapses having taken mephedrone, suffers seizures, or sudden chest pains.

    Other much more common nasty effects, usually associated with moderate or high doses, include feeling unbearably hot, feeling faint or that your heart is racing uncomfortably fast. Some people suffer paranoia, frightening hallucinations, confusion, panic and agitation. If you or a friend gets these symptoms, stay as calm as you can, move if necessary to a more relaxed, cooler environment and try to calm down. Lying down may be helpful, taking slow breaths, (breathing in and out of a paper bag helps with panic). If this doesn’t help, it may be necessary to get medical help. If it does help and you feel totally recovered, it is still sensible not to get back into the party and take more mephedrone.

    Some people have binged on mephedrone for several days. Eating, drinking, sleeping and resting are vital. Missing these things makes someone more likely to suffer from any of the potential harms, from the slightly unpleasant effects to seizures, psychosis and death.

  • As with other stimulants such as speed or cocaine, taking mephedrone if you have a heart problem or high blood-pressure is likely to be riskier.

    Mental health should be taken into account, as the chance of panic, paranoia, hallucinations and compulsive bingeing are likely to be increased if you have a disorder that predisposes you to these.

  • The risks of harm, including death, are likely to be increased by taking the drug whilst being on prescribed medication (especially antidepressants) or particularly taking other stimulant drugs such as amphetamines, MDMA and cocaine.

  • Not enough is currently known about mephedrone to say how harmful use would be over a long period of time. It is probable that the long term harms of mephedrone would be similar to drugs such as cocaine and MDMA due to their similar effects and structure. There is also some suggestion that mephedrone could be quite addictive, with cravings and low mood unless the drug is taken. However, there has not yet been enough rigorous scientific investigation into mephedrone addiction.

  • Mephedrone harm reduction advice is partly based on what we know of related drugs like amphetamines and MDMA, as not enough research has been done on mephedrone specifically.

    • Taking it with other drugs increases the risks

    • Deaths related to mephedrone usually involve large amounts of other stimulants such as cocaine, or depressants such as alcohol.

    • You may overheat when taking the drug

    • Mephedrone reportedly causes increases in body temperature. If you are dancing also you may overheat and become dehydrated. It is therefore a good idea to take regular breaks from dancing and drink moderate amounts of water.

    • Tolerance is a bad sign

    • As with most drugs, becoming tolerant to its effects is a sign that your brain chemistry is being changed by the drug, and that you are at high risk of addiction.

  • Is it actually plant food or bath salts?

    Before mephedrone was made illegal, people would sell mephedrone as plant fertilizer, bath salts or as a research chemical. This was a disguise for selling it for use as a recreational drug, to get around the law. Mephedrone cannot be used as plant food/fertilizer or as bath salts.

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