5-htp

Related Terms

• 5-Hydroxytroptophan, Griffonia plant seed extract, Griffonia simplicifolia, L-5-HTP, L-5-hydroxytroptophan, Natrol® 5-HTP, Natural Factors® 5-HTP, oxitriptan, serotonin, Tript-OH®, tryptophan.
• Select combination products: Gabadone™ (5-HTP, tryptophan, and other amino acids), Nature's Way 5-HTP (5-HTP, vitamin B6, vitamin C), Natural Factors® Tranquil Sleep (5-HTP, melatonin, L-theanine).
• Note: 5-HTP should not to be confused with L-tryptophan.

Background

• 5-HTP is the precursor of the neurotransmitter serotonin. Commercially available 5-HTP is obtained from the seeds of the plant Griffonia simplicifolia.
• 5-HTP has been suggested as a treatment for many conditions. Some research supports the use of 5-HTP in treating cerebellar ataxia, headache, depression, psychiatric disorders, and fibromyalgia, and as an appetite suppressant or weight loss agent. There is insufficient scientific evidence to support the use of 5-HTP for any other medical condition.
• 5-HTP may cause gastrointestinal disturbances, mood disturbances, seizure, or abnormal blood counts. Some side effects might result from contaminants in 5-HTP products.

Evidence

*Key to grades: 

A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

For full grading rationale, click here.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy. Consult a healthcare professional immediately if you experience side effects.

Allergies

• Avoid in individuals with a known allergy or hypersensitivity to 5-HTP. Signs of allergy may include rash, itching, or shortness of breath.

Side Effects and Warnings

• In light of the concern related to eosinophilia myalgia syndrome (EMS), use of 5-HTP should be supervised by a qualified healthcare provider.
• 5-HTP may cause abdominal pain, absence of menstrual bleeding, agitation, aggressiveness, anorexia, anxiety, depressed mood, diarrhea, dizziness, drowsiness, ear buzzing, eosinophilia, eosinophilia myalgia syndrome (EMS), euphoria, fatigue, gas, gastrointestinal side effects, hand wringing, headache, heartburn, hives, hypomania, impaired decision-making, increased appetite, increased blood cortisol or kynurenine, irritability, loss of inhibition, lowered blood pressure, lowered cholesterol, mania, muscle pain or weakness or breakdown, nausea, pacing, palpitations, psychic hyperkinetic syndrome, rapid speech, restlessness, seizure, scleroderma-like symptoms, sleep changes, slowed heart rate, sodium retention, strong muscle contractions, sweating, taste changes, vertigo, vivid dreams, vomiting, or weight gain.
• Use cautiously in patients with existing gastrointestinal disorders, as 5-HTP may cause worsening of symptoms.
• Use cautiously in patients with schizophrenia, due to the potential for worsening symptoms.
• Use cautiously in patients with HIV/AIDS, particularly HIV-1 infection.
• Use cautiously in patients with seizure disorders or those using agents that may lower the seizure threshold, due to increased risk of seizures.
• Use cautiously in patients with a history of mental disorders.
• Use cautiously in patients using CNS depressants. Drowsiness or sedation may occur. Use caution if driving or operating heavy machinery.
• Use cautiously in patients taking decarboxylase inhibitors.
• 5-HTP may cause low blood pressure. Caution is advised in patients taking drugs, herbs, or supplements that lower blood pressure.
• Use cautiously in patients with bradycardia (slow heart rate).
• Avoid in patients with eosinophilia syndromes, due to cases of eosinophilia and eosinophilia-myalgia syndrome (EMS).
• Avoid in infants with Down syndrome, due to the potential for spasm.
• Avoid in patients with mitochondrial encephalomyopathy.
• Avoid in patients with suicidal thoughts, based on suicide attempts following 5-HTP use.
• Avoid use in individuals using "party pills" (benzylpiperazine and trifluoromethylphenylpiperazine), based on population studies suggesting that the combination is associated with increased adverse effects from the party pills.
• Avoid in patients taking antidepressant medications (tricyclics [TCAs], monoamine oxidase inhibitors [MAOIs], selective serotonin reuptake inhibitors [SSRIs], nefazodone, trazodone, venlafaxine, mirtazapine, or bupropion) or any other medications that may affect serotonin, due to potential increases in serotonin levels and increased risk of serotonin toxicity syndrome.
• Avoid in women who are pregnant or lactating, due to a lack of safety data.
• Avoid in patients with a known allergy to 5-HTP-containing products. Signs of allergy to 5-HTP may include rash, itching, or shortness of breath.

Pregnancy and Breastfeeding

• Avoid in pregnant or breastfeeding women, due to a lack of available scientific evidence. 5-HTP products may contain contaminants or increase levels of prolactin, a hormone needed for milk production.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy.

Interactions with Drugs

• Note: 5-HTP is a precursor to serotonin; thus, it may interact with agents that modulate levels of serotonin.
• 5-HTP may cause low blood pressure. Caution is advised in patients taking drugs that lower blood pressure.
• 5-HTP may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be increased or decreased in the blood, and may cause increased or decreased effects or potentially serious adverse reactions. Patients using any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.
• 5-HTP may increase the amount of drowsiness caused by some drugs. Examples include benzodiazepines such as lorazepam (Ativan®) or diazepam (Valium®), barbiturates such as phenobarbital, narcotics such as codeine, some antidepressants, and alcohol. Caution is advised while driving or operating machinery.
• 5-HTP may interact with angiotensin-converting enzyme receptor blockers (ARBs), antianxiety agents (such as buspirone and trazodone), anticancer agents, antidepressants (including monoamine oxidase inhibitors [MAOIs] such as L-deprenyl, selective serotonin reuptake inhibitors [SSRIs], serotonin and norepinephrine reuptake inhibitors [SNRIs] such as venlafaxine, tetracyclics such as mirtazapine, or tricyclics [TCAs]), anti-inflammatories, antiobesity agents (such as phentermine), antiseizure agents, antipsychotic agents (such as haloperidol), barbiturates (such as pentobarbital), benzodiazepines, benzylpiperazine, cannabinoids (such as tetrahydrocannabinol), cholesterol-lowering agents, CNS depressants, decarboxylase inhibitors (such as carbidopa and benserazide), diltiazem, drugs that lower seizure threshold, growth hormones, hormonal agents, lithium carbonate, losartan, methamphetamine, metoclopramide, painkillers, sedatives, serotonin receptor antagonists (such as methysergide, nefazodone, cyproheptadine, and ritanserin), or thyroid hormones.

Interactions with Herbs and Dietary Supplements

• 5-HTP may cause low blood pressure. Caution is advised in patients taking herbs or supplements that lower blood pressure.
• 5-HTP may interfere with the way the body processes certain herbs or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of other herbs or supplements may become too high or too low in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system.
• 5-HTP may increase the amount of drowsiness caused by some herbs or supplements.
• 5-HTP may interact with Alpinia zerumbet, antianxiety agents (such as St. John's wort), anticancer agents, antidepressants (including monoamine oxidase inhibitors [MAOIs] and selective serotonin reuptake inhibitors [SSRIs]), anti-inflammatories, antiobesity agents, antioxidants, antiseizure agents, antipsychotics, cannabinoids, cholesterol-lowering agents, chromium, herbs that lower the seizure threshold, hormonal herbs and supplements, jujubosides from Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H.F.Chow, L-tyrosine, magnesium, melatonin, niacin, painkillers, protein, SAMe, sedatives, serotonin receptor antagonists, spinosin, theanine, thyroid herbs and supplements, tryptophan, tryptophan-containing foods, or vitamin B6.

Authors

• This information is based on a professional level monograph edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Selected References

Natural Standard developed the above evidence-based information based on a systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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3. Birdsall TC. 5-Hydroxytryptophan: a clinically-effective serotonin precursor. Altern Med Rev 1998;3(4):271-280.
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5. Caruso I, Sarzi Puttini P, Cazzola M, et al. Double-blind study of 5-hydroxytryptophan versus placebo in the treatment of primary fibromyalgia syndrome. J Int Med Res 1990;18(3):201-209.
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10. Halford JC, Harrold JA, Boyland EJ, et al. Serotonergic drugs: effects on appetite expression and use for the treatment of obesity. Drugs 2007;67(1):27-55.
11. Loftis JM, Turner EH. Novel treatment strategies for depression in patients with hepatitis C. Psychosomatics 2010;51(4):357-358.
12. Ohno Y, Imaki J, Mae Y, et al. Serotonergic modulation of extrapyramidal motor disorders in mice and rats: role of striatal 5-HT(3) and 5-HT(6) receptors. Neuropharmacology 2011;60(2-3):201-208
13. Schott DA, Nicolai J, de Vries JE, et al. Disorder in the serotonergic system due to tryptophan hydroxylation impairment: a cause of hypothalamic syndrome? Horm Res Paediatr 2010;73(1):68-73.
14. Shaw K, Turner J, Del Mar C. Tryptophan and 5-hydroxytryptophan for depression. Cochrane Database Syst Rev 2002;(1):CD003198.
15. Titus F, Davalos A, Alom J, et al. 5-Hydroxytryptophan versus methysergide in the prophylaxis of migraine. Randomized clinical trial. Eur Neurol 1986;25(5):327-329.