Media organisations including the BBC and The Guardian, as well as a news section in the Annals of Botany, incorrectly reported that mephedrone was commonly used as a plant fertiliser. In fact sellers of the drug described it as "plant food" because it was illegal to sell the compound for human consumption. In late 2009, UK newspapers began referring to the drug as meow or miaow (sometimes doubled as meow meow or miaow miaow), a name that was almost unknown on the street at the time. In November 2009, the tabloid newspaper, The Sun published a story stating that a man had ripped off his own scrotum whilst using mephedrone, but this story was later shown to be an online hoax. The Advisory Council on the Misuse of Drugs (ACMD) have suggested that the media coverage of the drug lead to increased usage of it.
A survey of 1000 secondary school pupils and university students in Tayside, conducted in February 2010, found that 20% of them had previously taken mephedrone. Although at the time it was available legally over the internet, only 10% of users reported purchasing it online, with most purchasing it from street dealers. Of those who had used mephedrone, 97% said that it was easy or very easy to obtain. Around 50% of users reported at least one negative effect associated with the use of mephedrone, with teeth grinding being the most common.
On 30 March 2010, Alan Johnson, then the Home Secretary, announced that mephedrone would be made illegal "within weeks" after the ACMD sent him a report on the use of cathinones. Prior to the ban being announced, Dr Polly Taylor, a member of the ACMD resigned, saying she "did not have trust" in the way the government would use the advice given by the ACMD. Eric Carlin, a member of the ACMD and former chairman of the English Drug Education Forum, also resigned after the announcement that mephedrone would be made illegal. He said that the decision by the Home Secretary was "unduly based on media and political pressure" and there was "little or no discussion about how our recommendation to classify this drug would be likely to impact on young people's behaviour." Some ex-members of the ACMD, and various charity groups have expressed concern regarding the banning of the drug, arguing it will inevitably criminalise users, particularly young people. Others have expressed concern that the drug will now be left in the hands of black market dealers, who will only compound the problem. The ACMD had run into problems with the UK Government in 2009 regarding drugs policy, after the government did not follow the advice of the ACMD to reclassify MDMA and cannabis, culminating in the dismissal of the ACMD chairman, David Nutt after he reiterated the ACMD's findings in an academic lecture. Eric Carlin's resignation was specifically linked to the criminalisation of mephedrone, and he stated: "We need to review our entire approach to drugs, dumping the idea that legally-sanctioned punishments for drug users should constitute a main part of the armoury in helping to solve our country’s drug problems. We need to stop harming people who need help and support". An editorial in the April 2010 edition of The Lancet questioned the decision to ban mephedrone, saying that the ACMD did not have enough evidence to judge the potential harms caused by mephedrone and arguing that policy makers should have sought to understand why young people took it and how they can be influenced to not take it. In Chemistry World, John Mann professor of chemistry at Queen's University Belfast, suggested that the UK create a law similar to the Federal Analog Act of the United States, which would have made mephedrone illegal as an analog of cathinone. In August 2010, James Brokenshire, the Home Office drugs minister, announced plans to create a new category in the Misuse of Drugs Act 1971 that would allow new legal highs to be made temporarily illegal, without the need for a vote in parliament, as was required to categorise mephedrone.
According to the Independent Scientific Committee on Drugs, since mephedrone was made illegal a street trade in the drug has emerged, with prices around double that of before the ban, at £20-£25 per gram. In September 2010, Druglink reported that the ban had had a mixed effect on mephedrone use, with it decreasing in some areas, remaining similar in others and becoming more prevalent in some areas. Other supposedly legal drugs have also filled the gap in the market since mephedrone was made illegal, including naphyrone (NRG-1) (since made illegal) and Ivory Wave, which has been found to contain MDPV, a compound made illegal at the same time as mephedrone. However it is possible that some products branded as Ivory Wave do not contain MDPV. When tested, some products sold six weeks after mephedrone was banned, advertised as NRG-1, NRG-2 and MDAI were found to be mephedrone.
 Effects There have been no formal published studies into the effects of mephedrone psychological and behavioural effects of mephedrone on humans, nor on animals from which the potential effects could be extrapolated. As a result the only information available comes from users themselves and clinical reports of acute mephedrone toxicity.:12 Psychologists at Liverpool John Moores University were to conduct research into the effects of mephedrone on up to 50 students already using the drug, when it was still legal in the UK. At the time the study was proposed, Les Iversen, the chair of the Advisory Council on the Misuse of Drugs called the experiments "pretty unethical". The study was discontinued in August 2010, following the change in the legal status of the drug.
 Intended effects Users have reported that mephedrone causes euphoria, stimulation, an enhanced appreciation for music, an elevated mood, decreased hostility, improved mental function and mild sexual stimulation; which are similar to the effects of cocaine, amphetamines and MDMA. These effects last different amounts of time, depending on the way the drug is taken. When taken orally, users report they can feel the effects within 15-45 minutes, when snorted the effects are felt within minutes. The effects last for between two and three hours when taken orally or nasally, but only half an hour if taken intravenously.:12 Out of 70 Dutch users of mephedrone, 58 described it as an overall pleasant experience and 12 described it as being an unpleasant experience. A survey of UK users, who had previously taken cocaine, found that most users found it produced a better quality and longer lasting high, was less addictive and carried the same risk to using cocaine.
 Side effects According to drugs counsellors on Teesside, UK, mephedrone can cause hallucinations, nausea, vomiting, blood circulation problems, rashes, anxiety, paranoia, fits and delusions. According to the drugs advice charity, Crew2000, other side effects may include poor concentration, poor short-term memory, increased heart rate, abnormal heart beats, anxiety, depression, increased sweating, dilated pupils, the inability to normally open the mouth, and teeth grinding. When snorted it can also cause nose bleeds and nose burns. A survey conducted by the National Addiction Centre, UK found that 51% of mephedrone users said they suffered from headaches, 43% from heart palpitations, 27% from nausea and 15% from cold or blue fingers, indicative of vasoconstriction occurring. Doctors at Guy's Hospital, London reported that of 15 patients they treated after taking mephedrone in 2009, 53.3% were agitated, 40% tachycardic, 20% had systolic hypertension and 20% had seizures; three required treatment with benzodiazepines, predominantly to control their agitation. They reported that none of their patients suffered from cold or blue peripheries, as other reports have done. Nine out of the 15 of patients had a Glasgow Coma Scale (GCS) of 15 or above, 4 had a GCS below 8, but these patients all reported using a central nervous system depressant, most commonly GHB, with mephedrone. The patients also reported polydrug use of a variety of compounds.
 Long-term effects Almost nothing is known about the long-term effects of the drug due to the short history of its use. BBC News reported that one person who used the drug for 18 months became dependent on the drug, in the end using it twice a week, had to be admitted to a psychiatric unit after he started experiencing hallucinations, agitation, excitability and mania.:13 Because of its similarity to cathinone, John Mann, has posited that mephedrone may cause impotence with long-term use.
 Typical use and consumption Mephedrone can come in the form of capsules, tablets or white powder that users may swallow, snort or inject. It is sometimes sold mixed with methylone in a product called bubbles in the UK and also mixed with other cathinones including ethcathinone, butylone, fluoromethcathinone and methedrone.:9 The Guardian reported that some users compulsively redose, consuming their whole supply when they are only meant to use a small dose and there have been other similar reports of users craving mephedrone, suggesting that it may be addictive.:13 A survey conducted in late 2009 by the National Addiction Centre (UK) found 41.3% of readers of Mixmag had used mephedrone in the last month, making it the fourth most popular drug amongst clubbers. Of those, two thirds snorted the drug and the average dosage per session was 0.9g; the length of sessions increased as the dosage increased. Users who snorted the drug reported using more per session than those who took it orally (0.97 g compared to 0.74 g) and also reported using it more often (5 days per month compared to 3 days per month). An Irish study of people on a methadone treatment program for heroin addicts found that 29 out of 209 patients tested positive for mephedrone usage.
 Harm reduction See also: Responsible drug use The drugs advice charity Lifeline recommends that to reduce the potential harm caused by using mephedrone, users should only use mephedrone occasionally (less than weekly), use less than 0.5g per session, dose orally rather than snorting the drug and avoid mixing it with alcohol and other drugs. Users should also drink plenty of water whilst taking the drug as it causes dehydration.