Herb & supplement monograph

5-htp Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how 5-htp interacts with medications. The heart of this page is the interaction list — every drug 5-htp is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what 5-htp is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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5-htp Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, most 5-htp drug interactions are theoretical rather than proven, so the risk of a clinically significant problem appears low for most people, with sensible caution around serotonin-raising medicines. None of the interactions are rated major, and all are graded as only possible, resting on lab or animal research or limited human reports rather than solid human studies.

Interactions deserving the most attention

The combinations that matter most involve serotonergic drugs, such as many antidepressants, because 5-HTP raises serotonin and stacking these effects could in theory lead to serotonin syndrome, though this has not yet been reported in people taking 5-HTP. Carbidopa is sometimes paired with 5-HTP on purpose, but together they may increase serotonin-related side effects like restlessness, anxiety, insomnia, and rapid speech. CNS depressants are also worth watching, since 5-HTP has caused drowsiness in clinical trials and adding another sedating medicine could compound that effect.

What the rest of the list means

The long list of interacting medications does not mean each combination is harmful. Most entries trace back to the same two theoretical concerns, added serotonin activity and added sedation, applied across hundreds of drugs. In many cases these predicted effects have not been shown to cause meaningful problems in people.

Check your medications against 5-htp

Based on HelloPharmacist’s 5-htp interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with 5-htp

398 medications have a known interaction with 5-htp, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against 5-htp using our pharmacist-reviewed interaction data.

AI summaries are generated from our 5-htp interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact 5-htp combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs 5-htp affects

Every type of medication (drug category) 5-htp is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 3 drug categories 5-htp interacts with

Carbidopa (lodosyn)Cns DepressantsSerotonergic Drugs

Carbidopa (Lodosyn)

Combining 5-HTP and carbidopa can increase the risk of serotonergic side effects.
Carbidopa is sometimes used with 5-HTP to minimize peripheral 5-HTP metabolism and boost the amount that reaches the brain. However, this combination might also increase the risk of some side effects including hypomania, restlessness, rapid speech, anxiety, insomnia, and aggressiveness. Combining carbidopa and 5-HTP might also increase the risk of scleroderma-like skin changes due to elevated serotonin levels.

Likelihood Possible Evidence D

Cns Depressants

Theoretically, concomitant use of 5-HTP with medications that cause sedation might have additive effects.
In clinical trials, 5-HTP has been associated with drowsiness and somnolence.

Likelihood Possible Evidence D

Serotonergic Drugs

Combining serotonergic drugs with 5-HTP might cause additive serotonergic effects.
5-HTP can increase serotonin levels and cause serotonergic effects. Theoretically, combining serotonergic drugs with 5-HTP might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders. However, serotonin syndrome with 5-HTP has not yet been reported in humans. Monitor patients for signs of serotonin syndrome and other serotonergic side effects if using 5-HTP with serotonergic drugs.

Likelihood Possible Evidence D

Monograph

5-htp: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

5-HTP is a compound your body uses to make serotonin, and people take it as a supplement hoping to improve mood, sleep, and headaches. Some early research is promising, but the overall evidence is limited and not conclusive. Because it can affect serotonin and may interact with medicines, talk to your pharmacist or doctor before using it.

Part used: Seeds (Griffonia simplicifolia) used as the natural source; the supplement is the purified amino acid
Common forms: Capsules, tablets, time-release tablets

People commonly use it for

Low mood or depression
Anxiety and stress
Sleep problems
Migraine headaches
Fibromyalgia
Appetite or weight management

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

May help some people but can cause side effects and affects serotonin, so use with care and professional guidance.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

5-HTP (5-hydroxytryptophan) is a natural compound that your body makes from the amino acid tryptophan. Your body then turns 5-HTP into serotonin, a brain chemical that helps control mood, sleep, and appetite.

The 5-HTP sold in supplements is not usually made in a lab from scratch. Instead, it most often comes from the seeds of an African shrub called Griffonia simplicifolia, which naturally contains a high amount of 5-HTP.

People take 5-HTP hoping to lift their mood, ease anxiety, sleep better, reduce migraine headaches, and help with conditions like fibromyalgia. It is sold over the counter as capsules and tablets.

How it works

5-HTP is a direct building block for serotonin, a chemical messenger in the brain and gut. After you take 5-HTP, your body can convert it into serotonin. Serotonin plays a role in mood, sleep, anxiety, pain signaling, and appetite.

Serotonin is also used to make melatonin, a hormone involved in the sleep cycle. This is one reason 5-HTP is studied for sleep.

Much of what we know about these pathways comes from laboratory and animal research, and how strongly 5-HTP raises serotonin in people can vary. Higher serotonin is not always better, which is part of why 5-HTP must be used carefully.

Effectiveness

Does 5-htp work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 20 uses evaluated

1 Possibly effective 1 Leans ineffective 18 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Possibly Effective Depression

Rating & evidence shown verbatim from Natural Medicines

Oral 5-HTP seems to improve symptoms of depression.

HelloPharmacist Explains reviewed by Dr. Brian Staiger, PharmD · July 2026

5-HTP may help with depression, but the research is limited. A Cochrane review found only two trials of good enough quality, covering 64 patients total, and these suggested 5-HTP and tryptophan worked better than placebo. However, the reviewers said the evidence was too weak to be conclusive and called for more studies on safety and effectiveness. Talk with your doctor before using 5-HTP, since proven antidepressants are available.

Fact-checked against 1 study

Studies referenced

Tryptophan and 5-hydroxytryptophan for depression. The Cochrane database of systematic reviews · 2002 · PMID 11869656

Possibly Ineffective Down syndrome

Rating & evidence shown verbatim from Natural Medicines

Oral 5-HTP does not seem to improve muscle tone or cognitive skills in patients with this condition.

Also studied for 18 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Alcohol use disorder

Rating & evidence shown verbatim from Natural Medicines

Oral 5-HTP has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Alzheimer disease

Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral 5-HTP for Alzheimer disease, there is insufficient reliable information about the clinical effects of 5-HTP for this condition.

Insufficient Reliable Evidence To Rate Anxiety

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP is beneficial in patients with anxiety disorders.

Insufficient Reliable Evidence To Rate Attention deficit-hyperactivity disorder (ADHD)

Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral 5-HTP for ADHD, there is insufficient reliable information about the clinical effects of 5-HTP for this condition.

Insufficient Reliable Evidence To Rate Cerebellar ataxia

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP reduces cerebellar ataxia symptoms.

Insufficient Reliable Evidence To Rate Fibromyalgia

Rating & evidence shown verbatim from Natural Medicines

Small clinical studies suggest that oral 5-HTP may improve symptoms of primary fibromyalgia syndrome.

Insufficient Reliable Evidence To Rate Inflammatory bowel disease (IBD)

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP is beneficial for IBD.

Insufficient Reliable Evidence To Rate Insomnia

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP is beneficial for insomnia.

Insufficient Reliable Evidence To Rate Menopausal symptoms

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP is beneficial for symptoms of menopause.

Insufficient Reliable Evidence To Rate Migraine headache

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP reduces frequency of migraines.

Insufficient Reliable Evidence To Rate Obesity

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP is beneficial in for weight loss.

Insufficient Reliable Evidence To Rate Obsessive-compulsive disorder (OCD)

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP is beneficial in patients with OCD.

Insufficient Reliable Evidence To Rate Opioid withdrawal

Rating & evidence shown verbatim from Natural Medicines

Oral 5-HTP has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Panic disorder

Rating & evidence shown verbatim from Natural Medicines

It is unclear if intravenous 5-HTP is beneficial for reducing anxiety in panic disorder.

Insufficient Reliable Evidence To Rate Parkinson disease

Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral 5-HTP is beneficial for improving Parkinson disease symptoms.

Insufficient Reliable Evidence To Rate Premenstrual syndrome (PMS)

Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral 5-HTP for PMS, there is insufficient reliable information about the clinical effects of 5-HTP for this condition.

Insufficient Reliable Evidence To Rate Seizures

Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral 5-HTP for seizures, there is insufficient reliable information about the clinical effects of 5-HTP for this condition.

Insufficient Reliable Evidence To Rate Tinnitus

Rating & evidence shown verbatim from Natural Medicines

Oral 5-HTP has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

HelloPharmacist Explains reviewed by Dr. Brian Staiger, PharmD · July 2026

There is not enough good research to say whether 5-HTP helps tinnitus. One small study tested a combination supplement that included 5-HTP along with Ginkgo biloba, magnesium, melatonin, vitamins, and zinc. Patients reported less tinnitus-related distress after 3 months, but the study had no comparison group, only 29 of 61 patients finished, and 5-HTP was not tested by itself. We cannot draw any conclusion about 5-HTP alone.

Fact-checked against 1 study

Studies referenced

Effectiveness of Tinnitan Duo® in Subjective Tinnitus with Emotional Affectation: A Prospective, Interventional Study. Journal of dietary supplements · 2023 · PMID 34219601

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

5-HTP is sold without a prescription, but that does not mean it is risk-free. Because it raises serotonin, taking too much—or combining it with other things that affect serotonin—can be a problem.

People with serotonin-related conditions, those taking medicines or other supplements that affect mood or serotonin, and people with liver or kidney problems should talk to a healthcare professional first.

In the past, some tryptophan supplements were linked to a serious illness called eosinophilia-myalgia syndrome (EMS), which was thought to be caused by contamination during manufacturing. While this was tied to L-tryptophan, it is a reason to choose high-quality, reputable products and to be cautious.

Pregnancy and breastfeeding: There is not enough reliable safety information for 5-HTP during pregnancy or breastfeeding. Because it affects brain chemistry, it is best to avoid it during these times unless your doctor specifically advises otherwise.

Children, older adults, and people with chronic health conditions should only use 5-HTP under guidance from a pharmacist or doctor.

Side effects

The most commonly reported side effects of 5-HTP are digestive, such as nausea, stomach upset, heartburn, diarrhea, and loss of appetite. Taking it with food may help reduce stomach upset for some people.

Other possible effects include drowsiness, headache, and feeling lightheaded.

A rare but serious concern is serotonin syndrome, which can happen when serotonin levels get too high—especially if 5-HTP is combined with other serotonin-affecting products. Warning signs include agitation, fast heartbeat, high body temperature, sweating, shivering, muscle stiffness or twitching, and confusion. This is a medical emergency—seek care right away if these occur.

5-htp: Reported Adverse Effects

Documented safety reports on 5-htp from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Orally, 5-HTP is generally well tolerated, short-term.

Most Common Adverse Effects:

Orally: Abdominal pain, anorexia, dizziness, diarrhea, drowsiness, fatigue, headache, insomnia, nausea, and vomiting. Severity appears to be dose-dependent.

Serious Adverse Effects (Rare):

Orally: Aggression, hallucinations, mania, severe gastrointestinal complaints.

Reports by condition

Anorexia Gastrointestinal

Orally, 5-HTP has been reported to cause gastrointestinal side effects such as nausea, vomiting, abdominal or epigastric pain, heartburn, constipation, diarrhea, flatulence, anorexia, and taste alteration at any dose. Severity may be dose-dependent and also related to how quickly doses are increased. Some data suggests that these effects may diminish or disappear with continued use of 5-HTP.

Anxiety Psychiatric

Orally, 5-HTP has been associated with euphoria, hypomania and mania, anxiety, insomnia, and aggressiveness. In patients with schizophrenia, a combination of high-dose 5-HTP, up to 6 grams daily, and carbidopa 150 mg daily was associated with transient increases in hallucinations, delusions, marked confusion, looseness of associations, flight of ideas, and a hyperkinetic syndrome consisting of restlessness, hand wringing, pacing, and an inability to sit quietly in a chair.

Iovieno, N., Dalton, E. D., Fava, M., and Mischoulon, D. Second-tier natural antidepressants: review and critique. J Affect.Disord. 2011;130(3):343-357.
Van Woert, M. H., Rosenbaum, D., Howieson, J., and Bowers, M. B., Jr. Long-term therapy of myoclonus and other neurologic disorders with L-5- hydroxytryptophan and carbidopa. N Engl J Med 1-13-1977;296(2):70-75.
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.
Pardo JV. Mania following addition of hydroxytryptophan to monoamine oxidase inhibitor. Gen Hosp Psychiatry 2012;34(1):102.e13-4.
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.

Cluster headache Neurologic/CNS

Orally, 5-HTP has been reported to cause drowsiness, dizziness, insomnia, fatigue, and headache.

Epilepsy Musculoskeletal

Orally, rhabdomyolysis was noted in one patient with progressive myoclonus epilepsy who was treated with 5-HTP 300 mg daily for 21 days.

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(8):783-791.

Hypotension Cardiovascular

Orally, palpitations have been reported with 5-HTP. Conversely, bradycardia has been reported in patients taking 5-HTP 0.4-2 grams daily in combination with carbidopa 100-300 mg daily. In patients with schizophrenia, a combination of 5-HTP in doses up to 6 grams daily and carbidopa 150 mg daily was associated with diaphoresis and mild diastolic hypotension, especially when doses were increased at a rate faster than 200 mg per day.

Iovieno, N., Dalton, E. D., Fava, M., and Mischoulon, D. Second-tier natural antidepressants: review and critique. J Affect.Disord. 2011;130(3):343-357.
De Benedittis G, Massei R. Serotonin precursors in chronic primary headache. A double-blind cross-over study with L-5-hydroxytryptophan vs. placebo. J Neurosurg Sci 1985;29:239-48.
Bastard, J., Truelle, J. L., and Emile, J. [Effectiveness of 5 hydroxy-tryptophan in Parkinson's disease]. Nouv Presse Med 9-11-1976;5(29):1836-1837.
Van Woert, M. H., Rosenbaum, D., Howieson, J., and Bowers, M. B., Jr. Long-term therapy of myoclonus and other neurologic disorders with L-5- hydroxytryptophan and carbidopa. N Engl J Med 1-13-1977;296(2):70-75.
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.

Myalgia Hematologic

Symptoms suggestive of eosinophilia myalgia syndrome (EMS) have been reported in some patients using 5-HTP. In one case, a woman was exposed to 5-HTP, tetrahydrobiopterin, carbidopa, and levodopa while administering them to her children for 2 years. Her diagnosis was not confirmed, and the validity of the tests performed on the 5-HTP product has been questioned. Other cases of eosinophilia or EMS in patients taking 5-HTP have been attributed to impurities that resemble previously identified contaminants found in L-tryptophan products. The L-tryptophan contaminants associated with EMS were linked to a specific manufacturer's production method that is not used in the preparation of 5-HTP. Although 5-HTP supplements have been associated with EMS, it seems that this adverse effect is likely due to the presence of contaminants in the 5-HTP products, not 5-HTP itself.

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.
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;26:2714-7.
Auffret, M., Comte, H., and Bene, J. Eosinophilia-myalgia syndrome induced by L-5 hydroxytryptophane: about three cases. Fund Clin Pharmacol 2013;Suppl 1(120):poster P2-204.
Das YT, Bagchi M, Bagchi D, Preuss HG. Safety of 5-hydroxy-L-tryptophan. Toxicol Lett 2004;150:111-22.
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(12):2261-5.
U.S. Food and Drug Administration. Impurities confirmed in dietary supplement 5-hydroxy-L-tryptophan. FDA Talk Paper, August 31, 1998; T98-48.
U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Nutritional Products, Labeling, and Dietary Supplements. Information Paper on L-Tryptophan and 5-hydroxy-L-tryptophan, February 2001.

Myasthenia gravis Dermatologic

Orally, 5-HTP has been reported to cause urticaria, other allergic-type skin reactions, and flushing. A scleroderma-like illness was reported in a 70-year-old man who had been taking 5-HTP 1400 mg daily and carbidopa 150 mg daily for 20 months. Elevated serotonin levels may be linked to this condition.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no official, standardized dose of 5-HTP that has been firmly established for any condition. Products vary widely in strength and form, including some time-release versions.

The safest approach is to follow the directions on the product label and to start low. Because 5-HTP affects serotonin, it is wise to check with your pharmacist or doctor before starting, especially if you take any medicines or other supplements.

Do not assume that taking more will work better—higher amounts increase the risk of side effects. If you do not notice a benefit or you have side effects, stop and talk to a healthcare professional.

Pregnancy & Breastfeeding

5-htp & Pregnancy

Insufficient reliable information

Insufficient reliable information available; avoid using.

5-htp & Breastfeeding

Insufficient reliable information

Insufficient reliable information available; avoid using.

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 32 references that drive our 5-htp monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Birdsall TC. 5-Hydroxytryptophan: A Clinically-Effective Serotonin Precursor. Altern Med Rev 1998;3:271-80.
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.
Cangiano C, Ceci F, Cancino 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. PubMed
U.S. Food and Drug Administration. Impurities confirmed in dietary supplement 5-hydroxy-L-tryptophan. FDA Talk Paper, August 31, 1998; T98-48.
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. PubMed
Poldinger W, Calanchini B, Schwarz W. A functional-dimensional approach to depression: serotonin deficiency as a target syndrome in a comparison of 5-hydroxytryptophan and fluvoxamine. Psychopathology 1991;24:53-81.
Ribeiro CA. L-5-Hydroxytryptophan in the prophylaxis of chronic tension-type headache: a double-blind, randomized, placebo-controlled study. Headache 2000;40:451-6.
U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Nutritional Products, Labeling, and Dietary Supplements. Information Paper on L-Tryptophan and 5-hydroxy-L-tryptophan, February 2001.
Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
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;26:2714-7.
Takahashi S, Kondo H, Kato N. Effect of l-5-hydroxytryptophan on brain monoamine metabolism and evaluation of its clinical effect in depressed patients. J Psychiatr Res 1975;12:177-87. PubMed
Iovieno, N., Dalton, E. D., Fava, M., and Mischoulon, D. Second-tier natural antidepressants: review and critique. J Affect.Disord. 2011;130(3):343-357. PubMed
den Boer JA, Westenberg HG. Behavioral, neuroendocrine, and biochemical effects of 5-hydroxytryptophan administration in panic disorder. Psychiatry Res 1990;31:267-78. PubMed
Jangid P, Malik P, Singh P, Sharma M, Gulia AK. Comparative study of efficacy of l-5-hydroxytryptophan and fluoxetine in patients presenting with first depressive episode. Asian J Psychiatr 2013;6:29-34. PubMed
Ceci F, Cangiano C, Cairella M, et al. The effects of oral 5-hydroxytryptophan administration on feeding behavior in obese adult female subjects. J Neural Transm 1989;76:109-17. PubMed
Angst J, Woggon B, Schoepf J. The treatment of depression with L-5-hydroxytryptophan versus imipramine. Results of two open and one double-blind study. Arch Psychiatr Nervenkr 1977;224:175-86. DOI
Titus F, Dávalos A, Alom J, Codina A. 5-Hydroxytryptophan versus methysergide in the prophylaxis of migraine. Randomized clinical trial. Eur Neurol 1986;25:327-9. PubMed
De Benedittis G, Massei R. Serotonin precursors in chronic primary headache. A double-blind cross-over study with L-5-hydroxytryptophan vs. placebo. J Neurosurg Sci 1985;29:239-48.
Van Woert, M. H., Rosenbaum, D., Howieson, J., and Bowers, M. B., Jr. Long-term therapy of myoclonus and other neurologic disorders with L-5- hydroxytryptophan and carbidopa. N Engl J Med 1-13-1977;296(2):70-75. PubMed
Wyatt, R. J., Vaughan, T., Galanter, M., Kaplan, J., and Green, R. Behavioral changes of chronic schizophrenic patients given L-5- hydroxytryptophan. Science 9-22-1972;177(54):1124-1126. PubMed
Chase, T. N., Ng, L. K., and Watanabe, A. M. Parkinson's disease. Modification by 5-hydroxytryptophan. Neurology 1972;22(5):479-484.
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. PubMed
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(8):783-791. PubMed
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. PubMed
Bastard, J., Truelle, J. L., and Emile, J. [Effectiveness of 5 hydroxy-tryptophan in Parkinson's disease]. Nouv Presse Med 9-11-1976;5(29):1836-1837.
Auffret, M., Comte, H., and Bene, J. Eosinophilia-myalgia syndrome induced by L-5 hydroxytryptophane: about three cases. Fund Clin Pharmacol 2013;Suppl 1(120):poster P2-204.
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.
Das YT, Bagchi M, Bagchi D, Preuss HG. Safety of 5-hydroxy-L-tryptophan. Toxicol Lett 2004;150:111-22. PubMed
Pardo JV. Mania following addition of hydroxytryptophan to monoamine oxidase inhibitor. Gen Hosp Psychiatry 2012;34(1):102.e13-4. PubMed
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(12):2261-5.
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(5):254-262. PubMed
Maffei ME. 5-Hydroxytryptophan (5-HTP): Natural Occurrence, Analysis, Biosynthesis, Biotechnology, Physiology and Toxicology. Int J Mol Sci. 2020;22(1):181. PubMed

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

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Brands that make products with 5-htp

489 brands in our database make a supplement containing 5-htp.

EBOOST 33 products Ekkovision 3 products Elevate Recovery Supplements 35 products Elite Labs USA 2 products Emeritt 1 product Energetix 283 products EntheoZen 3 products Enyotics Health Sciences 8 products Enzymatic Therapy 675 products Esmond Natural 87 products EST 12 products Eu Natural 54 products Everyday Health 69 products Evlution Nutrition 171 products Evogen Nutrition 3 products eXplicit Supplements 79 products Extreme Products 32 products Faktrition 16 products Femiwell 10 products Fight Labs 8 products Finest Nutrition 142 products Force Factor 65 products ForestLeaf 45 products Formutech Nutrition 5 products

Product directory

Supplement products with 5-htp

1,655 products in our database contain 5-htp. Open any to see its full ingredient list and every drug interaction we check.

Pharmacist Counseling Corner

5-htp: Common Questions

What is 5-htp used for, and does it work?

People use 5-htp for many reasons, but the evidence varies by use. According to the Natural Medicines database, there is at least some clinical evidence supporting 5-htp for Depression. For most other uses it has been studied for, the evidence is currently insufficient to rate. See the graded list on this page, and always confirm with your pharmacist or doctor.

Does 5-htp interact with prescription medications?

Yes. We list 398 medications with a known interaction with 5-htp. Use the checker above to see how 5-htp interacts with a specific drug.

How are 5-htp interactions rated?

Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.

Is it safe to take 5-htp with my medications?

It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.

Where does this 5-htp interaction information come from?

Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.

What is 5-htp used for?

People most commonly take it hoping to improve mood, ease anxiety, sleep better, or reduce migraines and fibromyalgia symptoms. The evidence for most of these uses is limited, so it is not proven to work.

Is 5-htp safe to take?

It is sold over the counter, but it is not risk-free. It can cause stomach upset and drowsiness, and because it raises serotonin it should be used carefully and with professional guidance.

Can I take 5-htp during pregnancy or while breastfeeding?

There is not enough safety information, so it is best to avoid 5-htp during pregnancy and breastfeeding unless your doctor specifically recommends it.

Will 5-htp help me sleep?

Some people use it for sleep because the body can turn it into serotonin and then melatonin, but the research is preliminary and it is not a proven sleep aid.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Products that contain 5-htp

A rotating sample of real supplements in our database that list 5-htp — open any to see its full ingredients and every drug interaction we check.

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5-htp Drug Interactions, Uses, Effectiveness, Safety & More

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5-htp Drug Interactions: The Bottom Line

Drugs that interact with 5-htp

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What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Likelihood — How Well It’s Documented

Where This Data Comes From

The kinds of drugs 5-htp affects

5-htp: Uses, Safety & Side Effects

Overview

How it works

Does 5-htp work?

Safety & precautions

Side effects

5-htp: Reported Adverse Effects

Dosing

5-htp & Pregnancy

5-htp & Breastfeeding

References & further reading

Brands that make products with 5-htp

Supplement products with 5-htp

5-htp: Common Questions

Related supplements & herbs

Products that contain 5-htp

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