Chemsex delves deep into London’s contemporary gay scene, where synthetic drug-induced sex parties are causing an alarming rise in HIV transmission and drug addiction. A group of gay men share their personal stories, offering insight into what motivates them to use these dangerous drugs as part of their sex lives. Chemsex is an emotional journey that contains powerful footage of what goes on behind the scenes. The story begins with a young man who mainlines £400 ($600) worth of drugs each week yet claims he isn’t really an addict. This makes it immediately and painfully clear how denial can increase the scale and destructive effects of drug use. Furthermore, it’s kept largely hidden because the drugs are illegal and the parties are private. In each individual story, scenes of domesticity alternate with those in clubs and treatment facilities. We meet Enrique, whose addiction has turned him from a college-educated professional into a homeless person who sells his body for drugs. Mark takes us on a tour of his gay sauna and the preventative measures he has taken there. And Simon, a drug user, receives help from David, who runs a sexual health clinic.