Due to being one of the most adulterated drug markets, the impurity of molly in different regions and at different times varies quite a bit – that is, there’s no such thing as the "most common adulterants." Besides MDMA, "ecstasy" or "molly" may contain varying levels of:
- Psychoactive substances designed to mimic the effects of MDMA like MDA (methylene-dioxyamphetamine a.k.a. “sass”) or “bath salts” (a general term for synthetic cathinones, a class of amphetamine-like stimulants);
- Stimulants like amphetamine, cocaine, caffeine or methamphetamine; or, more rarely
- Anesthetics such as ketamine (“Special K”) or dextromethorphan (DXM – an ingredient found in over-the-counter cough medicines).
All of these can significantly amplify potential harms. The most important thing for harm reduction is to know what you’re getting. According to Ecstasydata.org – an independent laboratory testing program of Erowid Center – among 250 samples they analyzed in 2014 that were sold as molly, 40 samples contained MDMA with adulterants, and nearly half (124) contained no MDMA at all!
- Ecstasydata.org, “Test Result Statistics: Summary Data,” (2015), http://www.ecstasydata.org/stats.php.