Mescaline' (3,4,5-trimethoxyphenethylamine) is a chemical substance. It occurs naturally in some cactuses, like the Peyote cactus, the Peruvian Torch cactus or the San Pedro cactus. Small amounts of it can also be found in certain members of the Fabaceae (bean) family, like Acacia berlandieri.
The chemical can cause hallucinations. In has been used as a drug in Native American religious ceremonies. It is illegal in many countries. Some people use it as an illegal drug.