We employ a five-step risk scale with values ranging from "very low" to "very high" within six categories: Acute toxicity, Long-term toxicity, Dependence, Cognitive problems, Unpleasant events, and Interactions.
These values are based on qualitative reviews of available knowledge, and should only be viewed as guidelines. They are also relative, so a score of "very low risk" does not mean the substance is risk-free. The scale assumes users are normal, healthy individuals; beware that even drugs which are well-tolerated by most people may nevertheless be harmful to some users. It also assumes normal use patterns; that is, if a given drug is only harmful when used in a certain way, yet is almost never used in that way, then the drug will be considered less harmful compared to a similar drug which is commonly used in a harmful way.
⦿⦿⦾⦾⦾ (Low risk)
Relatively few overdose deaths have been linked to mephedrone when considering how many people are assumed to have used the drug at some point. A literature review from 2015 found that mephedrone had been implicated in only 15 drug-related deaths, of which nine were registered as being caused by mephedrone alone . UK authorities estimate, based on national surveys done in 2010, that around 300,000 brits between the ages of 16 and 24 had used mephedrone in the previous year .
⦿⦿⦾⦾⦾ (Low risk)
Mephedrone appears to cause less damage to the heart than does cocaine, amphetamine, and MDMA. It appears to also be less harmful to the brain's serotonin system than MDMA, and less harmful for the dopamine system than methamphetamine . However, many people use mephedrone in relatively large doses at a time, and often more frequently than people use MDMA, which means that the total damage to the body from mephedrone use may be greater than this relative harm potential might suggest .
⦿⦿⦿⦿⦾ (High risik)
The risk of addiction from mephedrone use appears to be similar to that of amphetamine and cocaine. A study involving 1,006 mephedrone users reported that roughly half of the users found the drug addictive, while a different study involving 205 users found reports of addiction symptoms in only 17% of users .
Unlike MDMA, mephedrone can be used frequently without any major loss of effectiveness, i.e. without the user rapidly developing a tolerance to its effects. However, users commonly need to increase the dose considerably with more frequent use . The risk of becoming addicted to mephedrone probably increases if the drug is combined with alcohol, and possibly also nicotine [6, 10].
⦿⦿⦿⦾⦾ (Moderate risik)
Mephedrone use can lead to many of the same hangover effects as MDMA, including low mood, anxiety, irritability, and problems with memory and sleep. These effects may last for anywhere from a few days to a few weeks after the drug is last used. Frequent mephedrone users score lower on memory recall tests, and animal testing has demonstrated reduced memory recall for extended periods after using mephedrone, albeit without visible signs of damage to the animals' brains.
Some research indicates that mephedrone produces more transient (i.e. less long-lasting) after-effects on the brain's serotonin system when compared with MDMA. However, because mephedrone users tend to re-dose several times over the course of a session, it is not uncommon to experience a worse "crash" after mephedrone than after MDMA.
Mephedrone can, like most strong central nervous stimulants, trigger psychoses. This happens primarily in individuals with a predisposition to psychoses, but also in cases of overdose or severe sleep deprivation .
⦿⦿⦿⦿⦾ (High risk)
Mephedrone, like MDMA, tends to make users more open and sociable, and lowers inhibitions regarding intimacy with others. This may lead people to tell others things about themselves that they normally wouldn't divulge, or initiate a close relationship with someone they would normally want to keep at a safe distance. Many people also experience a heightened sex drive on mephedrone, and there are reports from the chemsex community of people consenting to sexual encounters that they would normally not consent to . This means it is generally a bad idea to take mephedrone with people one either cannot trust, or does not trust oneself around, since situations might arise that one will regret once the drug's effects have worn off. This risk is likely amplified by combining mephedrone with central nervous depressants such as alcohol, GHB, benzodiazepines, or z-hypnotics, as these all tend to lower inhibitions as well.
People with suicidal thoughts or severe depression should be especially wary of using mephedrone due to the potentially severe emotional "crash" after a heavy session. Among deaths where mephedrone use has been implicated as a factor, some reported self-harm as the proximate cause of death .
⦿⦿⦿⦾⦾ (Moderate risik)
Mephedrone should, like all central nervous stimulants, never be used in combination with any monoamine oxidase-inhibiting drugs or medications, known as MAOIs. This includes recreational drugs such as ayahuasca, changa, and psychedelics in the 2C-T-series, atypical antidepressants such as phenelzine and moclobemide, and anti-Parkinsons drugs such as rasagiline and selegiline. Taking mephedrone at the same time as (or soon after) an MAOI can lead to serotonin syndrome, an acute, potentially life-threatening medical emergency. Also, taking mephedrone with lithium or tramadol may lead to seizures.
In theory, any central nervous stimulant that releases large amounts of serotonin may lead to serotonin syndrome when combined with SSRI or SNRI-type antidepressants. However, this does not appear to be the case with MDMA, where such antidepressants merely (greatly) reduce the desirable drug effects . For mephedrone, the picture is somewhat less clear. There appears to be only one known case of someone on an SSRI developing serotonin syndrome after taking a very large amount of mephedrone (roughly 40 doses over the course of 4 hours) . For safety's sake, it is best to avoid combining mephedrone with antidepressants.
Mephedrone should never be combined with other central nervous stimulants, as this appears to amplify their harmful effects on the brain . Combining mephedrone with central nervous depressants, meanwhile, may delay the effects of a depressant overdose until the effects of mephedrone have worn off. If one nevertheless chooses to combine mephedrone with central nervous depressants, one must keep a close eye on both the dosage (in order to avoid taking too much) and the duration of the depressant in question (so as to not remain sedated long after the relatively short-lived effects of mephedrone have worn off).
It is generally not advisable to combine mephedrone with cannabis or psychedelics. Although the effects of mephedrone are similar to MDMA, the short-lived effects and often brutal comedown after mephedrone means there is a higher risk of the comedown triggering acute anxiety or psychosis, compared to equivalent combinations with MDMA instead of mephedrone. Dissociatives such as ketamine appear to be less of a problem in combination with mephedrone, as indicated by the fact that some people take ketamine near the end of a mephedrone session specifically to reduce the severity of the comedown.
Kombinasjon av mefedron med cannabis eller psykedelika frarådes som hovedregel. Den korte virketiden og kraftige "nedturen" til mefedron gjør dette mer risikabelt enn tilsvarende kombinasjoner ved MDMA-bruk, grunnet faren for en angst- eller psykosereaksjon. Dissosiativer som ketamin er trolig mindre problematiske å kombinere med mefedron, da disse i enkelte miljø brukes nettopp for å gjøre "nedturen" fra sentralstimulerende mer håndterlig.