"Amphetamine-type substances include oral ('meth'), smokable ('crystal meth') and injectable/rectally administered methamphetamine, together with a vast range of other substances, including PMA (4-methoxyamphetamine, 'Dr. Death'), PMMA (4-methoxymethamphetamine), 4-MTA (4-methylthioamphetamine, 'flatliners'), DMA (2,5-dimethoxyamphetamine), MPA (methiopropamine), etc. [32]. Meth is the default substance associated with chemsex among MSM subjects in Asia, followed by GHB/GBL and ketamine [33]. Furthermore, Schecke et al. [34] carried out an online survey with some 1050 German-speaking participants who provided information on substance use. They found that 27% used crystal meth in the last 12 months. Some 89% of those subjects used methamphetamine in a sexual setting, and 50% reported injecting this molecule.
"Meth acts on DA neuron terminals projecting from the ventral tegmental area to the nucleus accumbens, representing the reward system in the brain [35]. Indeed, there are differences in bioavailability levels between the different methamphetamine formulations; when injecting the molecule, the bioavailability (BA) levels will equal to 100%; with the smokable formulation, the BA levels exceed 90%, and with the oral meth-related BA levels may be of around 60% [36]."
Schifano F, Bonaccorso S, Arillotta D, et al. Drugs Used in "Chemsex"/Sexualized Drug Behaviour-Overview of the Related Clinical Psychopharmacological Issues. Brain Sci. 2025;15(5):424. Published 2025 Apr 22. doi:10.3390/brainsci15050424
