2-Bromomescaline (2-BM or 2-Br-M), also known as 2-bromo-3,4,5-trimethoxyphenethylamine, is a putative psychedelic drug of the scaline family and derivative of the phenethylamine hallucinogen mescaline which has an unusual 2-bromo substitution. It is an agonist for serotonin receptors, with a binding affinity of 215 nM at 5-HT<sub>1A</sub>, 513 nM at 5-HT<sub>2A</sub> and 379 nM at 5-HT<sub>2C</sub>, so while it is around 10times more tightly binding than mescaline at 5-HT<sub>1A</sub> and 5-HT<sub>2A</sub> receptors, it is over 20times more potent at 5-HT<sub>2C</sub>. The drug was 5-fold more potent in substituting for LSD than mescaline in rats. It is not known to have been tested in humans. 2-Bromomescaline was first described in the scientific literature, as a chemical intermediate, in 1972. It has been reported as a designer drug, first identified in Austria in January 2023. The drug is not a controlled substance in Canada as of 2025.