SOURCE NATURALS - L-Phenylalanine Powder - 3.53 oz. (100 g)DESCRIPTION L Phenylalanine, an essential amino acid, is a precursor of the amino acid tyrosine, and to a whole series of neurotransmitters and hormones. Phenylalanine is first converted to tyrosine, which becomes L dopa, which converts to norepinephrine, a key neurotransmitter and an adrenal hormone. L Phenylalanine is also a direct precursor of PEA (Phenylethylamine), another important neurotransmitter. DETAILS Package Description: 3. 53 oz (100 gm)