The young couple’s day wound down like any other ordinary Monday — the men took their dog for an afternoon trip to the vet, followed by dinner and wine in a London flat.

But about midnight in January, 18-year-old Miguel Jimenez decided he wanted something a little more exotic. He invited his boyfriend, an up-and-coming lawyer named Henry Hendron, then 34, to take GHB. Recreational users ingest GHB, a depressant and psychoactive drug, to heighten arousal and spark feelings of euphoria. A controlled substance in Britain and the United States, it is sometimes found at raves — and, more recently, in the small but controversial “chemsex” subculture of London, New York City and other urban areas.

Hendron declined the drug, saying he had work the next day. Jimenez took it anyway. “It was quite a nice experience and we went to sleep,” Hendron told the BBC in April. “I woke up and he was dead, next to me.”

After phoning for help, the lawyer tried in vain to resuscitate Jimenez. “At one point blood starts to trickle out of his mouth, and I’m thinking, ‘he must be alive.’ But he’s not,” Hendron told CNN in an interview. “I’ve broken his ribs or something, and moving that blood around.” When combined with alcohol, GHB can be fatal, slowing breathing or inducing comas.

When police arrived at Hendron’s apartment with the paramedics, the officers arrested the lawyer. Hendron pleaded guilty in March, for possession with intent to sell GHB and a stimulant, mephedrone.  

The use of such drugs is a central aspect of the chemsex scene. In November, the BMJ medical journal published an editorial warning that chemsex “needs to become a public health priority.” Chemsex, as they define it, is typically practiced by men who have sex with men while intoxicated, high on chemical cocktails of mephedrone, GHB, methamphetamine or other mind-altering substances.

Mephedrone, also known as “meow meow,” is a synthetic stimulant derived from khat, an African herb. As GHB use appears to be spiking in popularity in the United States, mephedrone is accruing new users in the United Kingdom. Although chemists first synthesized mephedrone in 1929, it’s a relative newcomer to the recreational-drug pantheon — a recent paper in the journal Lancet notes that it appeared in London about 2007. By 2015, it was responsible for 34 deaths, according to the Lancet study, up from 22 in 2014.

Taking GHB, mephedrone and crystal meth together is meant to “induce a feeling of instant rapport with sexual partners,” the authors of the BMJ paper write. The ultimate goal is better sex — for long periods of time, frequently and with multiple partners.

But Hannah McCall, an author of the editorial and a London-based reproductive-health expert, told The Washington Post in November she “wouldn’t call it outlandish behavior.” Rather, she wants chemsex participants to be aware of risks, which include unprotected sex and sharing needles. “A lot of people having chemsex make informed decisions, just as people using alcohol make informed decisions.”

The extent of chemsex’s popularity has been difficult to pin down. (One of the few studies to specifically address chemsex consists of interviews with 30 men.) In a survey of more than a thousand men who have sex with men in south London, 1 in 5 reported participating in chemsex at some point in the past five years. Part of the difficulty in assessing chemsex’s prevalence is because it’s such a new phenomenon — journalist Alex Klineberg, who detailed his experience with the chemsex scene for the Huffington Post, wrote that as recently as 2008, “nobody was talking about” chemsex.

What draws people to chemsex is up for debate. According to the handful of studies that exist, men may take chemsex drugs to “manage negative feelings, such as a lack of confidence and self esteem, internalised homophobia, and stigma about their HIV status,” McCall and her colleagues wrote in the BMJ. Others argue marginalized men use chemsex as a bonding mechanism — or simply because chemsex feels good.

In an interview with British magazine Gay Times, BBC Radio 4 journalist Mobeen Azhar recounted his experience hunting for chemsex anecdotes. “I actively searched for someone to tell me how they’d made an informed and calculated choice to use chems and, that for them, the chem scene is just recreation.” What he found instead, Azhar said, were stories tinged with sadness. “Even those who told me sex on chems made them feel ‘like a don’ would follow up such celebratory statements with tales of rejection, regret, loneliness and longing for intimacy,” he said. “These became reoccurring themes among every chem user I spoke to.”

Hendron, the lawyer, has seen a brief encounter with chemsex sweep away a promising future. Before Jimenez’s death, Hendron was a rising star of a barrister, who had represented Parliament member Nadine Dorries and celebrities such as Stella English, a winner of the British version of “The Apprentice.” And he was well-connected, having purchased about $1,400 worth of chemsex drugs from a producer at the BBC, Alexander Parkin.

Now, once a month, Hendron travels to Jimenez’s home country of Colombia to visit his boyfriend’s grave, CNN reports. “I may go to prison and whatever I get, I deserve. I have made some stupid decisions and you have to stand up and accept that,” Hendron said to the BBC in April. “But that’s the price that drugs make you pay.” On Monday, London’s Central Criminal Court sentenced Hendron to 140 hours of community service.

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