Many antidepressant drugs work, at least in part, by raising serotonin levels. The supplement 5-hydroxytryptophan (5-HTP) has been tried in cases of depression for a similar reason: the body uses 5-HTP to make serotonin, so providing the body with 5-HTP might, therefore, raise serotonin levels.

As a supplement, 5-HTP has also been proposed for all the same uses as other antidepressants, including aiding weight loss, preventing migraine headaches, decreasing the discomfort of fibromyalgia, improving sleep quality, and reducing anxiety.

5-HTP is not found in foods to any appreciable extent. For use as a supplement, it is manufactured from the seeds of an African plant (Griffonia simplicifolia).