ChemSex is a common term used by gay men on sexual networking sites and smartphone Apps.
ChemSex is NOT the same as recreational drug use.
It is a specific form of recreational drug use.
ChemSex is defined by the use of any combination of drugs that includes three specific drugs (“chems”) before or during sex by MSM (Men who have Sex with Men).
These three drugs are meth, meph and G.
• Methamphetamine (crystal/crystal meth/Tina/meth).
• Mephedrone (meph/drone).
• GHB/GBL* (G, Gina).
The definition applies specifically to MSM who are disproportionately affected by HIV/HCV/STIs, and can be more likely to have a higher number of sexual partners. ChemSex is associated with some cultural drivers unique to gay men and communities that include psychosocial idiosyncrasies and new technologies (geo-sexual networking Apps) that can facilitate faster introduction to new partners, and to "Chems". (See a longer description here)
Below; David Stuart puts ChemSex into historical and cultural context for an audience of healthcare providers.