To SmartBodyz Nutrition D, L-Phenylalanine Reprinted by permission from Smart Eats, Smart Supplements, and Smart Exercise by Dusty R. Green, M.Ed. D is used to relieve pain. L is used as a stimulant, appetite suppressant, and antidepressant. Phenylalanine also helps replace dopamine, the neurotransmitter responsible for feelings associated with sexual pleasure, confidence, and euphoria. Phenylalanine is the precursor to another amino acid called tyrosine.
Tyrosine also does all of the above except for one factor.
Eating chocolate causes the release of beta phenylethylamine, a neuromodulator associated with mood enhancement and sexual stimulation. Tyrosine does not appear to be as active in this role as chocolate and phenylalanine. This is the reason chocolate is referred to as a sex food. If you are a chocoholic and want to cut back, phenylalanine may be the answer for you. Phenylalanine and tyrosine compete with other amino acids.