Para-Chloromethamphetamine

Another study on rats found that 4-chloromethamphetamine was more potent at inducing conditioned taste aversion than methamphetamine.

4-CMA produces the head-twitch response in rodents similarly to 4-CA. This effect of 4-CMA can be blocked by a serotonin reuptake inhibitor.

4-Chloromethamphetamine was further investigated in the 1960s along with 4-CA and it was noted that they differed from their parent amphetamine and methamphetamine substances by exhibiting only a slight central stimulant effect in both animals and humans and that they acted like antidepressants rather than stimulants.

Studies in the 1970s found that a single dose of 10 mg/1 kg 4-CMA resulted in a decreased level of serotonin in the brain for several weeks.

4-Chloromethamphetamine was identified outside of the laboratory for the first time at the Tomorrowland festival edition 2015, where a tablet was found in possession of a drug dealer (see picture). In the following year, tablets with 4–CMA were also found in Romania, Austria and Croatia. Fortuitously, and for unknown reasons, 4-CMA disappeared briefly from the European rave scene after the Spring of 2016. However, a 2019 study of participants of a dance music festival in Belgium reported detection of 4-CMA in pills (out of 178 analyzed samples only one was mostly 4-CMA, while in one other 4-CMA was a minor ingredient).