Chemsex is the scenario in which two or more people take drugs with the intended purpose of increasing the pleasure of sex. Chemsex most commonly includes methamphetamine, mephedrone, or GHB (gamma hydroxybutyrate). The term Chemsex came out of the U.K., where it is believed to be a relatively common practice within the gay community. A 2014 study found that 20% of gay men in London had participated in Chemsex in the last five years.
Chem sex is also known as party and play.