4-MTA is p-methylthioamphetamine also known as 4-methylthioamphetamine. 4-MTA may be
synthesised by chemical reactions similar to those used to produce MDA. Recognised precursors
include 4-methythiophenylacetic acid and 4-methylthiobenzaldehyde. Other reagents include
nitroethane and n-butylamine. 4-MTA was originally synthesised as a potential antidepressant but
at present it has no therapeutic use.