5-HTP (5-Hydroxytryptophan, DL-5-Hydroxytryptophan) Molecular Formula: C11H12N2O3 Mol. Wt.: 220.22 Molecular Structure:: 5-HTP (L-5-Hydroxytryptophan) is a derivative of the amino acid tryptophan. In the human body, tryptophan is converted into 5-HTP, which then can be transformed into serotonin (a potent neurotransmitter in the brain). Although 5-HTP is not found at any significant level in a normal diet, tryptophan is found in a wide variety of protein foods. The 5-HTP used in dietary supplements is derived from the seeds of an African plant (Griffonia simplicifolia).