Also indexed as: 5-HTP
5-HTP is used by the human body to make serotonin, an important substance for normal nerve and brain function. Serotonin appears to play significant roles in sleep, emotional moods, pain control, inflammation, intestinal peristalsis, and other body functions.1
5-HTP is not present in significant amounts in a typical diet. The human body manufactures 5-HTP from L-tryptophan, a natural amino acid found in most dietary proteins. However, eating food that contains L-tryptophan does not significantly increase 5-HTP levels. Supplemental 5-HTP is naturally derived from the seeds of Griffonia simplicifolia, a West African medicinal plant.
5-HTP has been used in connection with the following conditions (refer to the individual health concern for complete information):
|Science Ratings||Health Concerns|
Weight loss and obesity
Bipolar disorder/manic depression
Parkinson’s disease (with Sinemet)
Seasonal affective disorder
and relatively consistent scientific data showing a substantial health benefit.
Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.
Disruptions in emotional well-being, including depression and anxiety, have been linked to serotonin imbalances in the brain.2 People with fibromyalgia often have low serotonin levels in their blood.3 4 5 Supplements of 5-HTP may increase serotonin synthesis in these cases. The cause of migraine headaches is related to abnormal serotonin function in blood vessels,6 and 5-HTP may help correct this abnormality. Insomnia has been associated with tryptophan deficiency in the tissues of the brain;7 therefore, 5-HTP may provide a remedy for this condition.
In a controlled trial, 5-HTP (300 mg per day) was shown to be effective in reducing many symptoms of fibromyalgia, including pain, morning stiffness, sleep disturbances, and anxiety.8
For depression, 300 mg per day is often effective, though much of the research used 5-HTP in combination with drugs or was uncontrolled.9 10 11 For insomnia, a single 100-mg nighttime dose of 5-HTP was sufficient to improve the duration and depth of sleep in one placebo-controlled trial.12 For migraine headaches, amounts ranging from 400–600 mg per day have been shown to be effective at reducing the frequency and severity of attacks in most clinical trials.13 14 15 16 17 For tension headaches, 100 mg of 5-HTP taken three times per day led to a significant decrease in consumption of pain-relievers, but no significant change in headache duration or intensity.18
Appetite reduction and weight loss (averaging 11 pounds in 12 weeks) has occurred with amounts of 600–900 mg daily.19 20 In another clinical trial, 750 mg per day has been shown to be effective at decreasing carbohydrate and fat intake, and promoting weight loss.21
During the clinical trials described above, some people taking large amounts of 5-HTP experienced gastrointestinal upset (e.g. nausea) or, less often, headache, sleepiness, muscle pain, or anxiety.
A substance known as “Peak X” has been found in low concentrations in several over-the-counter 5-HTP preparations. Some researchers think this substance may be linked22 23 24 to toxicity previously reported25 26 27 in a 1989 L-tryptophan contamination incident. However, there is serious question about whether Peak X is actually the toxic agent and it may be unrelated to the problems previously associated with L-tryptophan.28 29 30 31 32 33 34 35 Although two articles reported possible associations between 5-HTP consumption and toxicity symptoms similar to those attributed to contaminated L-tryprophan,36 37 evidence linking 5-HTP or Peak X with any toxicity symptoms remains speculative. Although the structure of Peak X has recently been identified, there is no firm evidence that this substance has caused or contributed to any toxicity or disease.38
Very high intakes of 5-HTP have caused muscle jerks in guinea pigs39 and both muscle jerks40 and diarrhea in mice.41 Injected 5-HTP has also caused kidney damage in rats.42 To date, these problems have not been reported in humans. “Serotonin syndrome,” a serious but uncommon condition caused by excessive amounts of serotonin, has not been reported to result from supplementation with 5-HTP; in theory it could be triggered by the supplement.43 However, the level of intake at which this toxic effect might potentially occur remains unknown.
5-HTP should not be taken with antidepressants, weight-control drugs, other serotonin-modifying agents, or substances known to cause liver damage, because in these cases 5-HTP may have excessive effects. People with liver disease may not be able to regulate 5-HTP adequately and those suffering from autoimmune diseases such as scleroderma may be more sensitive than others, to 5-HTP.44 These people should not take 5-HTP without consulting a knowledgeable healthcare professional. The safety of taking 5-HTP during pregnancy and breast-feeding is not known at this time.
Are there any drug
Certain medicines may interact with 5-hydroxytryptophan. Refer to drug interactions for a list of those medicines.
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20. Cangiano C, Ceci F, Cascino A, et al. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. Am J Clin Nutr 1992;56:863–7.
21. 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.
22. Williamson BL, Benson LM, Tomlinson AJ, et al. On-line HPLC-tandem mass spectrometry analysis of contaminants of L-tryptophan associated with the onset of the eosinophilia-myalgia syndrome. Toxicol Lett 1997;92:139–48.
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24. Williamson BL, Tomlinson AJ, Mishra PK, et al. Structural characterization of contaminants found in commercial preparations of melatonin: similarities to case-related compounds from L-tryptophan associated with eosinophilia-myalgia syndrome. Chem Res Toxicol 1998;11:234–40.
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28. Belongia EA, Hedberg CW, Gleich GJ, et al. An investigation of the cause of the eosinophilia-myalgia syndrome associated with tryptophan use. N Engl J Med 1990;323:357–65.
29. Mayeno AN, Lin F, Foote CS, et al. Characterization of “peak E,” a novel amino acid associated with eosinophilia-myalgia syndrome. Science 1990;250:1707–8.
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36. Michelson D, Page SW, Casey R, et al. An eosinophilia-myalgia syndrome related disorder associated with exposure to L-5-hydroxytryptophan. J Rheumatol 1994;21:2261–5.
37. Sternberg EM, Van Woert MH, Young SN, et al. Development of a scleroderma-like illness during therapy with L-5-hydroxytryptophan and carbidopa. N Engl J Med 1980;303(14):782–7.
38. Johnson KL, Klarskov K, Benson LM, et al. Presence of peak X and related compounds: the reported contaminant in case related 5-Hydroxy-L-tryptophan associated with eosinophilia-myalgia syndrome. J Rheumatol 1999;26(12):2714–7.
39. Hagan JJ, Hatcher JP, Slade PD. The role of 5-HT1D and 5-HT1A receptors in mediating 5-hydroxytryptophan induced myoclonic jerks in guinea pigs. Eur J Pharmacol 1995;294:743–51.
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44. Sternberg EM, Van Woert MH, Young SN, et al. Development of a scleroderma-like illness during therapy with L-5-hydroxytryptophan and carbidopa. N Engl J Med 1980;303:782–7.
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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires September 2008.