5-HTP (5-hydroxytryptophan) is an amino acid extracted from seeds of the Griffonia simplicifolia plant that crosses the blood-brain barrier and may help with pain and sleep disorders. It is converted to serotonin in the brain, possibly affecting dopamine and norepinephrine levels. It may take a month or longer to work and should not be combined with SSRI drugs.
(Source: Chronic Fatigue Syndrome, Fibromyalgia, and Other Invisible Illnesses – The Comprehensive Guide, by Katrina Berne, Ph.D. Published by Hunter House books and available at www.hunterhouse.com.)