Super-strength ecstasy pills containing potentially life-threatening levels of MDMA are in circulation in the UK for possibly the first time in five years, a non-profit has warned ahead of Glastonbury festival this weekend. The Loop, which has recently conducted drug checking at Manchester’s Parklife festival and in Bristol, has urged revellers to be cautious after testing ecstasy pills containing more than 300mg of MDMA, with average strength levels returning to pre-pandemic levels. Ravers may have become familiar with lower strength pills and could be caught unawares by the re-emergence of higher potency ecstasy, said Adam Waugh, training coordinator of The Loop. “The safest option is not to take pills. However, if someone is going to take them, it is safer to start with a quarter,” he added. “Wait at least 90 minutes before re-dosing, and do not assume that pills of a similar design have the same contents. Pills which look very similar can have different contents and be of differing strengths.” At Parklife, in Manchester, earlier this month, The Loop tested samples of green, purple and grey-coloured ecstasy tablets which had either been seized by police or placed in amnesty bins. The pills were of comparable strengths to those which have previously led to hospitalisations, and even deaths. “Variations in the illicit drug market increase risk,” said Prof Fiona Measham, the founder of The Loop and chair in criminology at the University of Liverpool. “Rapid on-site drug testing informs festival-goers, stakeholders and wider drug-using communities about what is in circulation and where the risk lies.” Ecstasy is a class A drug in the UK, alongside heroin, cocaine and others, and the maximum penalty for supply or production is life in prison and/or an unlimited fine. Possession can result in up to seven years in prison, and/or an unlimited fine. Last year, the government was criticised for effectively blocking The Loop from providing a non-public checking service at Parklife, which it had offered since 2014, without a specific Home Office licence but with the blessing of local authorities. It was licensed this year for the first time, after receiving a separate licence for a permanent public checking facility in Bristol, where health professionals deliver personalised harm reduction advice to people who bring their drugs for testing. This year, The Loop has tested more than 150 samples of drugs bought as ecstasy, finding that only 2% contained no MDMA, a significant decrease on 2021 when ecstasy pills often contained no MDMA. One in 10 of the pills tested this year contained strong doses of more than 250mg of MDMA. “It is younger and less experienced festival-goers who came of age during Covid and never experienced the super-strength pills of the 2010s who are particularly at risk,” added Measham. In 2022, at Leeds festival, 16-year-old David Celino died after taking one and a half ecstasy pills. He is one of 32 young people to die at music festivals since 2017 from drug-related causes, according to a study co-authored by Measham. Celino’s father criticised “bureaucracy” and “political ideology” for preventing a rollout of public drug checking services at festivals. In 2018, when there was a comparable percentage of high strength pills in circulation, 30% of MDMA-related deaths were among young people aged under 21. Testing in Europe has also indicated a correlation between the size of an ecstasy pill, and the amount of MDMA that it contains. The Loop is running a “#TakeQuarterSipWater” campaign this summer as part of its efforts to “meet festival attendees where they’re at”, with estimates that more than half of festival-goers take drugs. “By adopting a harm reduction approach on-site, we can keep people safe,” the organisation said. The Guardian has contacted organisers at Glastonbury festival for comment.