Drug Science or DrugScience, originally called the Independent Scientific Committee on Drugs (ISCD), is a UK-based drugs advisory committee proposed and initially funded by hedge fund manager Toby Jackson. It is chaired by Professor David Nutt and was officially launched on 15 January 2010 with the help of the Centre for Crime and Justice Studies. The primary aim of the committee is to review and investigate the scientific evidence of drug harms without the political interference that could result from government affiliation.

The establishment of the committee followed the controversial sacking of Professor Nutt, on 30 October 2009 as chair of the UK's statutory Advisory Council on the Misuse of Drugs by UK Home Secretary, Alan Johnson after the Equasy controversy. The controversy followed his Eve Saville Memorial Lecture (2009) at the Centre.

Drug Science initially focused on reviewing official risk estimates for psychedelic drugs, ecstasy and cannabis, and increasing warnings of the dangers of ketamine. In 2013, Drug Science launched the peer-review academic journal Drug Science, Policy and Law published by SAGE. They currently have four working groups Medical Cannabis, Medical Psychedelics, Medical Psychedelics, and Enhanced Harm Reduction.

In 2010, Drug Science published a ranking of drug harms in the UK, the results of which garnered significant media attention. Drugs were assessed on two metrics – harm to users and harms to society. The report found heroin, crack cocaine, and methamphetamine to be the most harmful drugs to individuals, with alcohol, heroin, and crack cocaine as the most harmful to others. Overall, alcohol was the most harmful drug, with heroin and crack cocaine in second and third place. Most notably, the report stated that the legal status of most drugs bears little relation to the harms associated with them – several class A drugs including ecstasy (MDMA), LSD and magic mushrooms featured at the very bottom of the list. Similar findings were found by a Europe-wide study conducted by 40 drug experts in 2015. Since then, drug ranking by total harm research has come to the same conclusion.

Methods used in drug harm comparison

The results of the study were based on the opinions and judgment of 15 researchers, doctors, and a journalist. These opinions were exchanged and discussed during a 1-day workshop in accordance with a decision-making procedure called Multiple-Criteria-Decision-Analysis (MCDA). This procedure attempts to structure the debate so as to eliminate biases, but given that it has no input other than the experience and knowledge of the participants involved, it is unlikely to be unbiased if the participants share a similar understanding of a subject, or if the science in the field is inadequate to make a good judgment.

Drug Science has expanded its MCDA method to a number of contexts to measure the harms of various drugs and drug policies.

Using a similar multi-criteria decision analysis process as the 2010 drug harm ranking, Drug Science looked to rank the harms of all nicotine-containing products, including cigarettes, cigars, nicotine patches and e-cigarettes. The report concluded that e-cigarettes are 95% less harmful than conventional cigarettes, advice which was subsequently used in a report by Public Health England on e-cigarettes and now forms part of the evidence-base for the positions of the UK Government and the National Health Service. This figure was widely reported on in the press, but remains controversial as the long-term harms of e-cigarettes remain unknown.