Revellers enjoyed plenty of mood enhancement along with the music at the Glastonbury Festival, but this year any euphoria was less likely to be fueled by so-called "legal highs" after organizers took a stand against them.
Glastonbury, which attracts more than 135,000 people, joined with other festivals earlier this year to ban the drugs, which mimic the effect of illegal drugs like Ecstasy, LSD and cannabis but are legal and have in the past been sold openly at stalls.
Britain's Association of Independent Festivals coordinated the campaign under the banner: "Don't be in the Dark About Legal Highs".
England-based consultant psychiatrist Ian Rodin, who is part of the medical team at Glastonbury, applauded the effort to highlight the risks of the drugs.
"The problem with legal highs is people had assumed that if they were harmful they would be illegal, so people haven't exercised the same caution as they would with an illegal drug," he said.
Also known as designer drugs, legal highs are flooding global markets, the United Nations Office on Drugs and Crime said last month.
New psychoactive substances (NPS), aimed at the same market as drugs like ecstasy, are proliferating, it said, with 348 types reported globally in over 90 countries at the end of 2013.
Deaths from the drugs, which can be sold freely as long as they are labeled "not suitable for human consumption", jumped from 10 in 2009 to at least 68 in 2012, according to Britain's National Programme on Substance Abuse Deaths.
The drugs are being created faster than authorities can keep up with them.
"The only reason they aren't illegal is because it's impossible for the law to keep up with it," Rodin said.
The government said the designer drug AMT, which acts in a similar way to LSD, should be banned along with other deadly substances in a group of chemicals known as tryptamines, including a drug called 5-MeO-DALT, know as "rock star" or "green beans".
AMT led to the death of a teenager in Southampton, southern England, last year.
Festival goer Jamie, aged 21, from North Wales, said he had seen the effects that legal highs could have.
"People think because it's legal, it's as safe as buying your tea-bags," he said. "But there's always a risk with everything you take."