Deaths caused by ketamine have increased twenty-fold since 2015, according to a study published in the Journal of Psychopharmacology. However, worryingly, these deaths are increasingly occurring with multiple drugs, raising doubts over whether single-substance drug policies can reduce harms.
A team of researchers from King’s College London analysed cause of death in England, Wales and Northern Ireland between 1999 and 2024 and found 696 deaths caused by ketamine between 1999 and 2024. This is the most detailed assessment to date of ketamine-related deaths in England, Wales, and Northern Ireland to date.
Ketamine is a Class B anaesthetic drug with hallucinogenic effects. Its low cost — around £15-30 for a gram compared to £80 for cocaine —could be driving increased consumption. The number of people using ketamine in the UK has been growing, with an estimated 299,000 people aged 16-59 reporting illicit ketamine use in 2024. This drug has been implicated in the deaths of many celebrities, and Elon Musk is reported to use ketamine to help with his moods.
Worryingly, the authors found that while the annual number of deaths with ketamine has risen over the past years, the proportion of deaths with only ketamine has decreased. Nowadays, users prefer multiple drugs, which is more dangerous. For example, opioids, cocaine, benzodiazepines, and gabapentinoids have been frequently co-implicated in deaths, with the average number of substances involved in each case also rising.
The problem is that mixing ketamine with depressant drugs like opioids and benzodiazepines makes it harder to judge the effect each drug is having, which can result in people taking more than intended.
The team also spotted a demographic shift. Traditionally, this has been a drug used by young people, but now deaths are increasingly occurring among older, socioeconomically disadvantaged, and dependent drug users, rather than being confined to younger recreational populations.
“We are seeing more ketamine-related deaths, but these deaths rarely involve ketamine alone. They are increasingly part of complex polydrug use patterns, often among people facing social disadvantage and entrenched drug dependence. This means single-drug policies, such as reclassification, are unlikely to tackle the real drivers of harm,” said Dr Caroline Copeland, lead author of the study from King’s College London and the Director of the National Programme on Substance Use Mortality.
The authors call for a more comprehensive way to deal with ketamine users, including better overdose prevention schemes, better integration of ketamine users into treatment pathways, and targeted education on the risks of polydrug use.
“Illicit ketamine use has moved beyond the recreational setting. To reduce deaths, we need harm reduction, treatment, and social support strategies that reflect the realities of polydrug use – not just legislative changes focused on one substance,” concluded Dr Copeland.
Pullen J, Corkery JM, McKnight R, Copeland CS. Deaths following illicit ketamine use in England, Wales and Northern Ireland 1999-2024: An update report to inform the reclassification debate. J Psychopharmacol. 2025 Sep 29:2698811251373058.