2-phenylethylamine

Phenethylamine (PEA), also known as β-phenylethylamine (β-PEA) and 2-phenylethylamine is an organic compound and a natural monoamine alkaloid, a trace amine, and also the name of a class of chemicals with many members that are well known for their psychoactive and stimulant effects.
Phenylethylamine functions as a monoaminergic neuromodulator and, to a lesser extent, a neurotransmitter in the human central nervous system. It is biosynthesized from the amino acid L-phenylalanine by enzymatic decarboxylation via the enzyme aromatic L-amino acid decarboxylase. In addition to its presence in mammals, phenethylamine is found in many other organisms and foods, such as chocolate, especially after microbial fermentation. It is sold as a dietary supplement for purported mood and weight loss-related therapeutic benefits; however, orally ingested phenethylamine experiences extensive first-pass metabolism by monoamine oxidase B (MAO-B) and then aldehyde dehydrogenase (ALDH), which metabolize it into phenylacetic acid. This prevents significant concentrations from reaching the brain when taken in low doses.
The group of phenethylamine derivatives is referred to as the phenethylamines. Substituted phenethylamines, substituted amphetamines, and substituted methylenedioxyphenethylamines (MDxx) are a series of broad and diverse classes of compounds derived from phenethylamine that include empathogens, stimulants, psychedelics, anxiolytics (hypnotics) and entactogens, as well as anorectics, bronchodilators, decongestants, and antidepressants, among others.