Phenylethylamine is known as the “love drug”.Phenethylamine, or β-phenylethylamine or 2-phenylethylamine, is an alkaloid and monoamine. Phenethylamine also has a constitutional isomer α-phenylethylamine (1-phenylethylamine), which has two stereoisomers: (R)-(+)-1-phenylethylamine and (S)-(-)-1-phenylethylamine. In the human brain, 2-phenethylamine is believed to function as a neuromodulator or neurotransmitter (trace amine). Phenethylamine is a natural compound biosynthesized from the amino acid phenylalanine by enzymatic decarboxylation. It is also found in many foods such as chocolate, especially after microbial fermentation. However trace amounts from food is quickly metabolized by the enzyme MAO-B, preventing significant concentrations from reaching the brain.Phenylethylamine is a precursor to the neurotransmitter phenylethanolamine.
In the early 1980s, researcher Michael Liebowitz, author of the popular 1983 book The Chemistry of Love, remarked to reporters that “chocolate is loaded with PEA.” This became the focus for an article in The New York Times, which was then taken up by the wire services, then by magazine free-lancers, and evolved into the now-eponymous “chocolate theory of love.” However, as noted earlier, phenethylamine from food is rapidly metabolized by the enzyme MAO-B, preventing significant concentrations from reaching the brain, however when taken in higher doses it has potent perceptible psychoactive effect.