5-hydroxytryptophan (5-HTP) can be converted to serotonin in the body. It is often used for depression. It has less evidence for insomnia and anxiety.

5-HTP is a chemical byproduct of the protein building block L-tryptophan. It is produced commercially from the seeds of an African plant known as Griffonia simplicifolia. 5-HTP works in the brain and central nervous system by increasing the production of the chemical serotonin. Serotonin can affect sleep, appetite, temperature, sexual behavior, and pain sensation.

Since 5-HTP increases serotonin levels, it is used for conditions in which serotonin is believed to play an important role. These include depression, anxiety, and many other conditions, but there is no good scientific evidence to support most of these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for 5-HTP are as follows:

Possibly effective for…

• Depression. Taking 5-HTP by mouth seems to improve symptoms of depression in some people. It might work as well as some prescription antidepressant drugs.

Possibly ineffective for…

• Down syndrome. Most research shows that taking 5-HTP by mouth does not improve muscle strength or development in children with Down syndrome.

There is interest in using 5-HTP for a number of other purposes, but there isn’t enough reliable information to say whether it might be helpful.

When taken by mouth: It is possibly safe to take 5-HTP in doses of up to 400 mg daily for up to one year. The most common side effects include heartburn, stomach pain, nausea, vomiting, diarrhea, drowsiness, sexual problems, and muscle problems. Large doses of 5-HTP, such as 6-10 grams daily, are possibly unsafe. These doses have been linked to severe stomach problems and muscle spasms.

Some people who have taken 5-HTP have developed a serious health condition called eosinophilia-myalgia syndrome (EMS). Some people think EMS might be caused by an accidental contaminant in some 5-HTP products. But there’s not enough scientific evidence to know if EMS is caused by 5-HTP, a contaminant, or some other factor. Until more is known, 5-HTP should be used cautiously.

Special precautions & warnings:

Pregnancy and breast-feeding: There isn’t enough reliable information to know if 5-HTP is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.

Children: It is possibly safe for children to take 5-HTP by mouth at appropriate doses. In children under 12 years of age, 5-HTP seems to be safe at a dose of up to 5 mg/kg daily for up to 3 years.

Surgery: 5-HTP can affect a brain chemical called serotonin. Some drugs administered during surgery can also affect serotonin. Taking 5-HTP before surgery might cause too much serotonin in the brain and can result in serious side effects including heart problems, shivering, and anxiety. Tell patients to stop taking 5-HTP at least 2 weeks before surgery.

Moderate

Be cautious with this combination.

Carbidopa (Lodosyn)

5-HTP can affect the brain. Carbidopa can also affect the brain. Taking 5-HTP along with carbidopa can increase the risk of serious side effects including rapid speech, anxiety, aggressiveness, and others.

Sedative medications (CNS depressants)

5-HTP might cause sleepiness and slowed breathing. Some medications, called sedatives, can also cause sleepiness and slowed breathing. Taking 5-HTP with sedative medications might cause breathing problems and/or too much sleepiness.

Serotonergic drugs

5-HTP might increase a brain chemical called serotonin. Some medications also have this effect. Taking 5-HTP along with these medications might increase serotonin too much. This might cause serious side effects including heart problems, seizures, and vomiting.

Herbs and supplements with sedative properties

5-HTP might cause sleepiness and slowed breathing. Taking it along with other supplements with similar effects might cause too much sleepiness and/or slowed breathing in some people. Examples of supplements with this effect include hops, kava, L-tryptophan, melatonin, and valerian.

Herbs and supplements with serotonergic properties

5-HTP increases a brain chemical called serotonin. Taking it along with other supplements that have this effect might cause serious side effects, including heart problems, seizures, and vomiting. Examples of supplements with this effect include black seed, L-tryptophan, SAMe, and St. John’s wort.

There are no known interactions with foods.

5-HTP has most often been used by adults in doses of 150-800 mg daily. Very large doses of 5-HTP, such as 6-10 grams daily, can cause serious side effects and should be avoided. Speak with a healthcare provider to find out what dose might be best for a specific condition.

2-Amino-3-(5-Hydroxy-1H-Indol-3-yl) Propanoic Acid, 5 Hydroxy-Tryptophan, 5 Hydroxy-Tryptophane, 5-Hydroxytryptophan, 5-Hydroxytryptophane, 5-Hydroxy L-Tryptophan, 5-Hydroxy L-Tryptophane, 5-Hydroxy Tryptophan, 5-L-Hydroxytryptophan, L-5 HTP, L-5-Hydroxytryptophan, L-5-Hydroxytryptophane, Oxitriptan.

To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.

1. Meloni M, Figorilli M, Carta M, et al. Preliminary finding of a randomized, double-blind, placebo-controlled, crossover study to evaluate the safety and efficacy of 5-hydroxytryptophan on REM sleep behavior disorder in Parkinson’s disease. Sleep Breath 2021. View abstract.
2. Knäpper J, Girauta MV, Coromina J. Effectiveness of Tinnitan Duo® in Subjective Tinnitus with Emotional Affectation: A Prospective, Interventional Study. J Diet Suppl 2021;1-14. View abstract.
3. Zamoscik V, Schmidt SNL, Bravo R, et al. Tryptophan-enriched diet or 5-hydroxytryptophan supplementation given in a randomized controlled trial impacts social cognition on a neural and behavioral level. Sci Rep 2021;11:21637. View abstract.
4. Maffei ME. 5-Hydroxytryptophan (5-HTP): Natural Occurrence, Analysis, Biosynthesis, Biotechnology, Physiology and Toxicology. Int J Mol Sci. 2020;22:181. View abstract.
5. Meloni M, Puligheddu M, Sanna F, et al. Efficacy and safety of 5-Hydroxytryptophan on levodopa-induced motor complications in Parkinson’s disease: A preliminary finding. J Neurol Sci. 2020;415:116869. View abstract.
6. Yousefzadeh F, Sahebolzamani E, Sadri A, et al. 5-Hydroxytryptophan as adjuvant therapy in treatment of moderate to severe obsessive-compulsive disorder: a double-blind randomized trial with placebo control. Int Clin Psychopharmacol. 2020;35:254-262. View abstract.
7. Javelle F, Lampit A, Bloch W, Häussermann P, Johnson SL, Zimmer P. Effects of 5-hydroxytryptophan on distinct types of depression: a systematic review and meta-analysis. Nutr Rev 2020;78:77-88. View abstract.
8. Meloni M, Puligheddu M, Carta M, Cannas A, Figorilli M, Defazio G. Efficacy and safety of 5-hydroxytryptophan on depression and apathy in Parkinson’s disease: a preliminary finding. Eur J Neurol 2020;27:779-786. View abstract.
9. Israelyan N, Del Colle A, Li Z, et al. Effects of Serotonin and Slow-Release 5-Hydroxytryptophan on Gastrointestinal Motility in a Mouse Model of Depression. Gastroenterology. 2019;157:507-521.e4. View abstract.
10. Michelson D, Page SW, Casey R, et al. An eosinophilia-myaligia syndrome related disorder associated with exposure to l-5-hydroxytryptophan. J Rheumatol 1994;21:2261-5. View abstract.
11. Lemaire PA, Adosraku RK. An HPLC method for the direct assay of the serotonin precursor, 5-hydroxytrophan, in seeds of Griffonia simplicifolia. Phytochem Anal 2002;13:333-7.View abstract.
12. Pardo JV. Mania following addition of hydroxytryptophan to monoamine oxidase inhibitor. Gen Hosp Psychiatry 2012;34:102.e13-4.
13. Chen D, Liu Y, He W, Wang H, Wang Z. Neurotransmitter-precursor-supplement intervention for detoxified heroin addicts. J Huazhong Univ Sci Technolog Med Sci 2012;32:422-7.
14. Gendle MH, Young EL, Romano AC. Effects of oral 5-hydroxytryptophan on a standardized planning task: insight into possible dopamine/serotonin interactions in the forebrain. Hum Psychopharmacol 2013;28:270-3.
15. U.S. Food and Drug Administration Pharmacy Compounding Advisory Committee meeting June 17-18, 2015. Available at: www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials/drugs/pharmacycompoundingadvisorycommittee/ucm455276.pdf (accessed 8/21/15).
16. U.S. Food and Drug Administration. Orphan drug designations and approvals. Available at: www.accessdata.fda.gov/scripts/opdlisting/oopd/index.cfm (accessed 8/20/2015).
17. Das YT, Bagchi M, Bagchi D, Preuss HG. Safety of 5-hydroxy-L-tryptophan. Toxicol Lett 2004;150:111-22. View abstract.
18. Weise P, Koch R, Shaw KN, Rosenfeld MJ. The use of 5-HTP in the treatment of Down’s syndrome. Pediatrics 1974;54165-8. View abstract.
19. Bazelon M, Paine RS, Cowie VA, et al. Reversal of hypotonia in infants with Down’s syndrome by administration of 5-hydroxytryptophan. Lancet 1967;1:1130-3. View abstract.
20. Sano I. Therapy of depression with L-5-hydroxytryptophan (L-5-HTP). Psychiatria et Neurologia Japonicas 1972;74:584.
21. Klein P, Lees A, and Stern G. Consequences of chronic 5-hydroxytryptophan in parkinsonian instability of gait and balance and in other neurological disorders. Adv Neurol 1986;45:603-604.
22. VanPraag, H. M. and Korf, J. 5-Hydroxytryptophan as antidepressant: The predictive value of the probenecid test. Psychopharmacol.Bull. 1972;8:34-35.
23. Sicuteri F. 5-hydroxytryptophan in the prophylaxis of migraine. Pharmacological Research Communications 1972;4:213-218.
24. Rosano Burgio, F., Borgatti, R., Scarabello, E., and Lanzi, G. Headache in children and adolescents. Proceedings of the First International Symposium on Headache in Children and Adolecents. 1989;339-47.
25. Mathew NT. 5-hydroxytryptophan in the prophylaxis of migraine: a double-blind study. Headache 1978;18:111.
26. De Benedittis G, Massei R. 5-HT precursors in migraine prophylaxis: a double-blind cross-over study with L-5-hydroxytryptophan. Clin J Pain 1986;2:123-129.
27. Wyatt, R. J., Vaughan, T., Kaplan, J., Galanter, M., and Green, R. 5-Hydroxytryptophan and chronic schizophrenia. In: Barchas J and Usdin E. Serotonin and Behavior. New York: Acedemic Press;1973.
28. Brodie HKH, Sack R, and Siever L. Clinical studies of L-5-hydroxytryptophan in depression. In: Barchas J and Usdin E. Serotonin and behavior. New York: Academic Press;1973.
29. Auffret, M., Comte, H., and Bene, J. Eosinophilia-myalgia syndrome induced by L-5 hydroxytryptophane: about three cases. Fund Clin Pharmacol 2013;Suppl 1:poster P2-204.
30. Cangiano C, Laviano A, Del Ben M, et al. Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients. Int J Obes Relat Metab Disord 1998;22:648-54. View abstract.
31. Ju, C. Y. and Tsai, C. T. Serotonergic mechanisms involved in the suppression of feeding by 5-HTP in rats. Chin J Physiol 1995;38:235-240. View abstract.
32. Pranzatelli, M. R., Tate, E., Galvan, I., and Wheeler, A. A controlled trial of 5-hydroxy-L-tryptophan for ataxia in progressive myoclonus epilepsy. Clin Neurol.Neurosurg. 1996;98:161-164. View abstract.
33. Frith, C. D., Johnston, E. C., Joseph, M. H., Powell, R. J., and Watts, R. W. Double-blind clinical trial of 5-hydroxytryptophan in a case of Lesch- Nyhan syndrome. J Neurol Neurosurg.Psychiatry 1976;39:656-662. View abstract.
34. Bastard, J., Truelle, J. L., and Emile, J. [Effectiveness of 5 hydroxy-tryptophan in Parkinson’s disease]. Nouv Presse Med 9-11-1976;5:1836-1837. View abstract.
35. Trouillas P, Serratrice G, Laplane D, et al. Levorotatory form of 5-hydroxytryptophan in Friedreich’s ataxia. Results of a double-blind drug-placebo cooperative study. Arch Neurol 1995;52:456-60. View abstract.
36. Wessel K, Hermsdörfer J, Deger K, et al. Double-blind crossover study with levorotatory form of hydroxytryptophan in patients with degenerative cerebellar diseases. Arch Neurol 1995;52:451-5. View abstract.
37. Alino, J. J., Gutierrez, J. L., and Iglesias, M. L. 5-Hydroxytryptophan (5-HTP) and a MAOI (nialamide) in the treatment of depressions. A double-blind controlled study. Int Pharmacopsychiatry 1976;11:8-15. View abstract.
38. Pranzatelli, M. R., Tate, E., Huang, Y., Haas, R. H., Bodensteiner, J., Ashwal, S., and Franz, D. Neuropharmacology of progressive myoclonus epilepsy: response to 5- hydroxy-L-tryptophan. Epilepsia 1995;36:783-791. View abstract.
39. Thomson, J., Rankin, H., Ashcroft, G. W., Yates, C. M., McQueen, J. K., and Cummings, S. W. The treatment of depression in general practice: a comparison of L- tryptophan, amitriptyline, and a combination of L-tryptophan and amitriptyline with placebo. Psychol Med 1982;12:741-751. View abstract.
40. Trouillas, P., Garde, A., Robert, J. M., Renaud, B., Adeleine, P., Bard, J., and Brudon, F. [Regression of the cerebellar syndrome under long-term administration of 5-HTP or the combination of 5-HTP and benserazide. 26 cases quantified and treated using computer methods]. Rev Neurol.(Paris) 1982;138:415-435. View abstract.
41. Thal, L. J., Sharpless, N. S., Wolfson, L., and Katzman, R. Treatment of myoclonus with L-5-hydroxytryptophan and carbidopa: clinical, electrophysiological, and biochemical observations. Ann Neurol 1980;7:570-576. View abstract.
42. van Hiele LJ. l-5-Hydroxytryptophan in depression: the first substitution therapy in psychiatry? The treatment of 99 out-patients with ‘therapy-resistant’ depressions. Neuropsychobiology 1980;6:230-40. View abstract.
43. Magnussen, I. and Nielsen-Kudsk, F. Bioavailability and related pharmacokinetics in man of orally administered L-5-hydroxytryptophan in steady state. Acta Pharmacol Toxicol.(Copenh) 1980;46:257-262. View abstract.
44. Trouillas, P., Garde, A., Robert, J. M., and Adeleine, P. [Regression of human cerebellar ataxia under long term administration of 5-hydroxytryptophan]. C.R.Seances Acad Sci III 1-5-1981;292:119-122. View abstract.
45. Pueschel SM, Reed RB, Cronk CE, Goldstein BI. 5-hydroxytryptophan and pyridoxine. Their effects in young children with Down’s syndrome. Am J Dis Child 1980;134:838-44. View abstract.
46. Longo G, Rudoi I, Iannuccelli M, Strinati R, Panizon F. [Treatment of essential headache in developmental age with L-5-HTP (cross over double-blind study versus placebo)]. Pediatr Med Chir 1984;6:241-5. View abstract.
47. Bono, G., Micieli, G., Sances, G., Calvani, M., and Nappi, G. L-5HTP treatment in primary headaches: an attempt at clinical identification of responsive patients. Cephalalgia 1984;4:159-165. View abstract.
48. Quadbeck, H., Lehmann, E., and Tegeler, J. Comparison of the antidepressant action of tryptophan, tryptophan/5- hydroxytryptophan combination and nomifensine. Neuropsychobiology 1984;11:111-115. View abstract.
49. van Praag, H. M. In search of the mode of action of antidepressants: 5-HTP/tyrosine mixtures in depression. Adv Biochem Psychopharmacol. 1984;39:301-314. View abstract.
50. Trouillas P. Regression of cerebellar syndrome with long-term administration of 5-HTP or the combination of 5-HTP-benserazide: 21 cases with quantified symptoms processed by computer. Ital J Neurol Sci 1984;5:253-266. View abstract.
51. Magnussen, I., Jensen, T. S., Rand, J. H., and Van Woert, M. H. Plasma accumula