L-tryptophan is one of the eight essential amino acids obtained through food. In the brain, L-tryptophan is converted to an important neurotransmitter called serotonin, which is involved in regulation of mood, appetite, sleep and behavior. L-tryptophan has been used in alternative medicine as an aid to treat such conditions as depression, migraines, panic attacks and premenstrual syndrome. Talk to your doctor before using L-tryptophan to treat any medical condition.
A 2002 study published in the "Cochrane Database Systematic Reviews" found that L-tryptophan is more effective than placebo in treating depressive disorders in adults. The study included two trials with a total of 64 patients with unipolar depression. Researchers reported that further studies are needed to evaluate the efficacy and safety of tryptophan before widespread use of the supplement can be recommended.
Migraine, a type of painful headache, is related to a deficiency of tryptophan in the brain, according to a 2006 study published in the "International Journal of Headache." The study involved 16 controls and 16 migraine sufferers who consumed an amino acid drink that produced a short-term reduction in serotonin synthesis by omitting L-tryptophan. According to researchers, migraine sufferers reported more intense headaches than controls. The study suggests that tryptophan depletion intensifies migraine symptoms and might contribute to the development of migraines.
Premenstrual dysphoric disorder, or PMDD, is a severe form of premenstrual syndrome, marked by depression symptoms, irritability and tension before menstruation. A 1994 study published in the "Journal of Psychiatry and Neuroscience" found that L-tryptophan at a dosage of 6 g per day may ameliorate the symptoms of PMDD.
The antidepressant effects of L-tryptophan are related to its ability to increase the synthesis of serotonin in the brain. Drugs.com cites that clinical trials have shown that L-tryptophan causes a significant increase in the levels of 5-hydroxyindoleacetic acid, a serotonin metabolite. The study indicates an increased turnover of serotonin in the brain.