Mescaline ( 3,4,5 - trimethoxyphenethylamine ) is both one of the most widely studied of the hallucinogens, and one of the weakest (by volume). Quantitatively, mescaline serves as a sort of a standard among hallucinogens.

Peyote (Lophophora Williamsii) is a spineless cactus with a long root. It grows in the southwesterm United States and Mexico. Its crown, or 'button', is used for psychedelic purposes. It is cut from the cactus and dried into a hard brown disc. The disc, sometimes referred to as a 'mescal button', contains a methoxylated amphetamine: mescaline (C11H17NO3) (3,4,5-trimethoxy-ß-phenethylamine).The primary natural sources of mescaline are peyote (Lophophora williamsii or Lophophora diffusa); San Pedro cactus (Trichocereus pachanoi); and Peruvian Torch (Trichocereus peruvianus).

Mescaline is found in many types of cacti, most prominently in peyote (lophophora williamsii), San Pedro (trichocerus pachanoi) and the Peruvian Torch (trichocerus peruvianus). The mescaline content of the various mescaline containing cacti varies greatly between species and individual samples. Following is an estimate of the mescaline contents of three species. Quantities obtained the various cacti which contain this compound are:

1. Lophophora williamsii - 300 mg / 27 g dried material
2. Trichocerus pachanoi - 300 mg / 100 g dried material
3. Trichocerus peruvianus - 300 mg / 37.5 g dried material

Both dopamine and norepinephrine have the exact carbon skeleton and an oxygenation pattern similar to mescaline. The main metabolite of mescaline is 3,4,5 - trimethoxyphenylacetic acid, which appears to be produced enzymatically by something similar to diamine oxidase. Users experience a loss of spatial and temporal awareness and at higher dosages hallucinations.

Formal Chemical Name (IUPAC)
3,4,5 - trimethoxyphenethylamine