5-Hydroxytryptophan, or 5-HTP, (also called L-5-hydroxytryptophan or levo-5-hydroxytryptophan) is a natural compound manufactured in the body as a metabolite of L-tryptophan, an amino acid found in a variety of dietary proteins. Supplemental 5-HTP is derived from the seeds of the West African medicinal plant Griffonia simplicifolia.
The body uses 5-HTP to produce serotonin, a neurotransmitter involved in sleep, moods, appetite, pain control, and other body functions. Because 5-HTP is inactive in the body until it is converted into serotonin, the physiological effects of 5-HTP supplementation depend upon its ability to increase serotonin production.
Doses of 5-HTP used in clinical trials have ranged from 100-400 mg/day for migraine to 900 mg/day for weight loss, and this dosage range appears to be safe for most people. Reported side-effects, including gastrointestinal upset, headache, sleepiness, and anxiety, are usually mild. 5-HTP may produce harmful interactions with some drugs, including many antidepressants and appetite suppressants. People taking antidepressants or other prescription medications should consult a physician before using 5-HTP.