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Dietary supplement

5-HTP & Melatonin Ingredients & Drug Interactions

by Swanson

5-HTP & Melatonin label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking 5-HTP & Melatonin against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

5-HTP & Melatonin is a dietary supplement by Swanson with 2 active ingredients. Its ingredients are commonly taken for trouble falling asleep (insomnia), jet lag, delayed sleep phase syndrome.Based on those ingredients, 1,496 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Melatonin, L-5-Hydroxytryptophan. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against 5-HTP & Melatonin by Swanson

Ask about any prescription or over-the-counter medication and we check it for interactions with 5-HTP & Melatonin by Swanson — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of 5-HTP & Melatonin by Swanson

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains two active ingredients: melatonin, a hormone that regulates your sleep-wake cycle, and L-5-hydroxytryptophan (5-HTP), an amino acid your body uses to make serotonin, a chemical that affects mood and sleep. The capsules also contain inactive ingredients—rice flour, hypromellose (a thickener and binder), and magnesium stearate (a lubricant).

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: Sleep support and relaxation before bedtime.
  • We looked for evidence on: Insomnia, Delayed sleep phase syndrome (DSPS), Jet lag, Non-24-hour sleep wake disorder, Shift work disorder, Beta blocker-induced insomnia — and 4 related terms.
  • The strongest evidence on file: Melatonin is rated "Likely Effective" for Delayed sleep phase syndrome (DSPS) (Natural Medicines).
  • Also on file: Melatonin is rated "Likely Effective" for Non-24-hour sleep wake disorder.
  • Also on file: 5-htp is rated "Possibly Effective" for Depression.

Melatonin is likely effective for two specific sleep disorders: non-24-hour sleep-wake disorder and delayed sleep phase syndrome (where you're a natural night owl and can't shift to conventional sleep times). It's possibly effective for pre-procedural anxiety and sunburn, and possibly effective for high blood pressure, though the evidence is less solid.

5-HTP is possibly effective for depression but has insufficient evidence for panic disorder, Alzheimer's disease, or cerebellar ataxia. For Down syndrome, the available evidence suggests it may not be effective.

The bottom line: melatonin has the clearer track record for sleep timing, while 5-HTP's benefit for mood remains uncertain.

The evidence, ingredient by ingredient Melatonin 5-htp

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Melatonin is generally well tolerated for short-term use, though long-term safety is less certain and product quality varies. Common side effects are dizziness, drowsiness, headache, and nausea.

Rarely, melatonin may increase seizure risk. Long-term use has been linked to changes in growth hormones, cortisol, and sperm quality in some reports, and mood changes including depression, nervousness, and in rare cases hallucinations or delusions.

5-HTP is generally well tolerated short-term but has not been adequately studied for safety during pregnancy or breastfeeding—the data advises against use in both cases unless your doctor directs otherwise. Common side effects include stomach pain, nausea, diarrhea, drowsiness, fatigue, headache, and insomnia, often dose-dependent.

Serious but rare effects include aggression, hallucinations, and mania. The safety notes for melatonin do not address pregnancy or breastfeeding, so there isn't enough data on file to advise either way for that ingredient.

Side effects, ingredient by ingredient Melatonin 5-htp

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 2 of the 2 matched ingredients can interact with medications — 5-htp, Melatonin.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; seizure medications; immunosuppressants / transplant drugs; diabetes medications; Parkinson's medications.
  • For scale: 1,497 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, check with your pharmacist if you take blood thinners like warfarin, heart medications including nifedipine, seizure medications, immune-suppressing drugs, blood sugar medications, or blood pressure drugs—melatonin interacts with all of these. Also double-check if you're on sedating medications, antidepressants, migraine drugs, or any serotonin-based psychiatric medication, since 5-HTP can add to their effects.

And if you take carbidopa for Parkinson's disease, you'll want to discuss this combination specifically.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This combination may help people with specific sleep disorders or those looking to support sleep and mood naturally, but it comes with documented interactions and side effects you need to be aware of. If you take any blood thinners, heart medications, seizure medications, psychiatric drugs, or diabetes medications, check with your pharmacist or doctor first—the interactions here are real and can affect how your drugs work.

Talk through your complete medication list with us before starting.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 24, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about 5-HTP & Melatonin, straight from the product label.

Brand Swanson
Barcode (UPC) 087614027647
Net contents 30 Veggie Cap(s)
Market status On market
Date entered into DSLD Oct 24, 2024
DSLD ID 308442
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for 5-HTP & Melatonin by Swanson, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Veggie Capsule(s)
Maximum serving Sizes:
1 Veggie Capsule(s)
Servings per container
30
UPC/BARCODE
087614027647
IngredientAmount% DV
Melatonin3 mg--
L-5-Hydroxytryptophan50 mg--

Other ingredients: Rice Flour, Hypromellose, Magnesium Stearate

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, take one veggie capsule with water one-half hour before bedtime.

Precautions

Warning: For adults only.

As melatonin may produce drowsiness, do not drive an automobile or operate heavy equipment after taking.

Do not take this product if you are pregnant or nursing, taking a prescription antidepressant, have an autoimmune condition or a depressive disorder, or are under 16 years of age. Consult your healthcare provider before use if you have a medical condition or if you are taking any prescription medications.

Do not take this product if you are pregnant or nursing, taking a prescription antidepressant, have an autoimmune condition or a depressive disorder, or are under 16 years of age. Keep out of reach of children.

Do not use if seal is broken.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Formulation

Sleep support 2 in 1 formula

FDA Statement of Identity

Dietary Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

5-HTP & Melatonin by Swanson label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

5-HTP & Melatonin label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in 5-HTP & Melatonin by Swanson

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Veggie Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Melatonin

Interacts with
1,461 drugs
3 mg per serving

Melatonin is a hormone your body makes naturally to help control your sleep-wake cycle, and the supplement form is widely used to help with sleep timi...

Melatonin monograph & interactions

L-5-Hydroxytryptophan

Interacts with
398 drugs
50 mg per serving Form: Griffonia simplicifolia seed extract

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 rese...

L-5-Hydroxytryptophan monograph & interactions

Other (inactive) ingredients: Rice Flour, Hypromellose, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

5-HTP & Melatonin by Swanson Drug Interactions

Want to check YOUR meds against 5-HTP & Melatonin?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
1,496Drugs
1,185 Moderate 311 Minor

Ingredients driving the most interactions

Melatonin 1,461
L-5-Hydroxytryptophan 398

Individual Drug Interactions

The ingredients in 5-HTP & Melatonin interact with 1,496 drugs. Click any drug to see the details.

2 of the 2 ingredients in 5-HTP & Melatonin interact with drugs. Each result below shows which ingredient is responsible. Melatonin L-5-Hydroxytryptophan

Each ingredient & the kinds of drugs it affects

For each ingredient in 5-HTP & Melatonin with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Melatonin18 drug types · 1,461 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, melatonin may have anticoagulant effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
There are isolated case reports of minor bleeding and decreased prothrombin activity in people taking melatonin with warfarin (Coumadin). The mechanism, if any, of this interaction is unknown. Taking melatonin orally seems to decrease coagulation activity within one hour of dosing in healthy men.

Likelihood Possible Evidence B
Anticonvulsants

Theoretically, melatonin may reduce the effects of anticonvulsants. Some clinical research suggests that melatonin may increase the frequency of seizures in certain patients, particularly children with neurological impairment.

Likelihood Possible Evidence B
Antidiabetes Drugs

Theoretically, taking melatonin with antidiabetes drugs might increase the risk of hypoglycemia.
Some clinical research shows that melatonin reduces levels of fasting blood glucose and improves glycemic control. However, other research suggests that melatonin might impair glucose utilization and increase insulin resistance, while other research has found no effect on glucose levels. Until more is known, use melatonin cautiously in combination with antidiabetes drugs.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, taking melatonin with antihypertensive drugs might increase the risk of hypotension or hypertension.
Some clinical research suggests that taking melatonin decreases blood pressure in healthy adults. Also, melatonin seems to lower systolic and diastolic blood pressure in individuals with high blood pressure at nighttime or untreated essential hypertension. However, melatonin seems to worsen blood pressure in patients who are taking antihypertensive medications. Immediate-release melatonin 5 mg at night in combination with nifedipine GITS (Procardia XL) increases systolic blood pressure an average of 6.5 mmHg, diastolic blood pressure by an average of 4.9 mmHg, and heart rate by 3.9 bpm. Also, results from animal research suggest that melatonin reduces the effectiveness of certain antihypertensive drugs, including methoxamine and clonidine.

Likelihood Possible Evidence A
Caffeine

Theoretically, taking caffeine with melatonin might increase levels of melatonin.
Some evidence suggests that caffeine consumption can decrease endogenous melatonin levels, while other evidence suggests that caffeine increases endogenous melatonin levels. When administered in combination with melatonin supplements, caffeine seems to increase melatonin effects and levels. The reason for this discrepancy is not completely clear. Part of the discrepancy may result from the fact that caffeine can inhibit melatonin synthesis as well as inhibit melatonin metabolism. By functioning as an adenosine receptor antagonist, caffeine may indirectly inhibit the synthesis of melatonin. Conversely, because melatonin and caffeine are both metabolized by cytochrome P450 1A2 (CYP1A2) enzyme, concomitant use of melatonin and caffeine may reduce the metabolism of melatonin, resulting in higher serum levels.

Likelihood Probable Evidence B
Cns Depressants

Theoretically, taking melatonin might increase the sedative effects of CNS depressants.
Melatonin has sedative effects. Theoretically, concomitant use of melatonin with alcohol, benzodiazepines, or other sedative drugs might cause additive sedation.

Likelihood Possible Evidence D
Contraceptive Drugs

Theoretically, taking contraceptive drugs with melatonin might increase the effects and adverse effects of melatonin.
Contraceptive drugs can increase the levels of endogenous melatonin. Theoretically, these drugs may increase the effects and adverse effects of oral melatonin.

Likelihood Probable Evidence B
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP1A2. Also, other CYP1A2 substrates might decrease the metabolism of melatonin, increasing melatonin levels.
Melatonin is metabolized in the liver primarily by the CYP2C19 and CYP1A2 enzymes. Theoretically, combined administration of melatonin with drugs metabolized by the CYP1A2 enzyme might reduce the metabolism of these drugs, resulting in increased serum levels. Conversely, some drugs metabolized by CYP1A2 may inhibit the metabolism of melatonin, resulting in increased serum levels of melatonin. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Probable Evidence D
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP2C19. Also, other CYP2C19 substrates might decrease the metabolism of melatonin, increasing melatonin levels.
Melatonin is metabolized in the liver primarily by the CYP2C19 and CYP1A2 enzymes. Theoretically, combined administration of melatonin with certain drugs metabolized by the CYP2C19 enzyme may reduce the metabolism of these drugs, resulting in increased serum levels. Conversely, some drugs metabolized by CYP2C19 may inhibit the metabolism of melatonin, resulting in increased serum levels of melatonin. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Probable Evidence D
Fluvoxamine (Luvox)

Theoretically, taking fluvoxamine with melatonin might increase levels of melatonin.
Fluvoxamine can significantly increase melatonin levels. In some cases, fluvoxamine might increase bioavailability of exogenously administered melatonin by up to 20 times. Some researchers think this might be a beneficial interaction and be potentially useful for cases of refractory insomnia. However, this interaction might also cause unwanted excessive drowsiness and possibly other adverse effects. Fluvoxamine is known to increase endogenous melatonin secretion. It seems to increase serum levels of exogenously administered melatonin possibly by decreasing melatonin metabolism by inhibiting cytochrome P450 (CYP450) 1A2 and 2C19 or by inhibiting melatonin elimination. This effect has been found in healthy people taking fluvoxamine 50-75 mg and melatonin 5 mg.

Likelihood Probable Evidence B
Immunosuppressants

Theoretically, melatonin might interfere with immunosuppressive therapy.
Melatonin can stimulate immune function. Theoretically, melatonin might interfere with immunosuppressive therapy.

Likelihood Possible Evidence B
Methamphetamine (Desoxyn)

Theoretically, taking melatonin with methamphetamine may increase the adverse effects of methamphetamine.
Animal research suggests that melatonin exacerbates the adverse effects of methamphetamine, resulting in greater depression of tryptophan hydroxylase (TPH) and tyrosine hydroxylase (TH) activity, as well as a significant reduction in dopamine levels. This has not been shown in humans.

Likelihood Possible Evidence D
Nifedipine Gits (Procardia Xl)

Theoretically, taking melatonin with extended release nifedipine reduces the effects of nifedipine.
Melatonin can decrease the effectiveness of extended release nifedipine (GITS). Immediate-release melatonin 5 mg at night in combination with nifedipine GITS 30-60 mg daily increases systolic and blood pressure by an average of 6.5 mmHg and 4.9 mmHg, respectively. Concomitant use with melatonin also increases heart rate by 3.9 bpm. The mechanism of this interaction is not known.

Likelihood Probable Evidence B
Seizure Threshold Lowering Drugs

Theoretically, taking melatonin with drugs that lower the seizure threshold might increase the risk of seizure activity.
Some clinical evidence suggests that melatonin may increase the frequency of seizures in certain patients, particularly children with neurological disabilities.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, melatonin may have antiplatelet effects and may increase the risk of bleeding with warfarin.
Three cases of increased prothrombin time have been reported for patients aged 48-72 years who took melatonin orally in combination with warfarin. However, three cases of decreased prothrombin time have also been reported for patients aged 51-84 years who took melatonin orally in combination with warfarin. Until more is known, use melatonin cautiously in patients taking warfarin.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP2D6.
Laboratory research suggests that certain lots of melatonin inhibit CYP2D6. Theoretically, combined administration of melatonin with certain drugs metabolized by the CYP2D6 enzyme may reduce the metabolism of these drugs, resulting in increased serum levels. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP3A4.
Laboratory research shows that certain lots of melatonin inhibit CYP3A4. Theoretically, combined administration of melatonin with certain drugs metabolized by CYP3A4 may reduce the metabolism of these drugs, resulting in increased serum levels. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Possible Evidence D
Flumazenil (Romazicon)

Theoretically, taking flumazenil with melatonin might reduce the effects of melatonin.
Animal research shows that flumazenil may inhibit the effect of melatonin.

Likelihood Possible Evidence D
Melatonin full monograph & interactions

L-5-Hydroxytryptophan3 drug types · 398 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
L-5-Hydroxytryptophan full monograph & interactions
The maker

Brand information

Manufacturer and brand details for 5-HTP & Melatonin, from the product label.

Swanson

See all Swanson products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
www.swanson.com
Pharmacist Counseling Corner

5-HTP & Melatonin by Swanson: Common Questions

Does 5-HTP & Melatonin by Swanson interact with any medications?
Yes. Based on its ingredients, 5-HTP & Melatonin has a known interaction with 1,496 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
5-HTP & Melatonin contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm pregnant or nursing?
The data advises against 5-HTP during pregnancy and breastfeeding—there isn't enough reliable safety information. For melatonin, there's no data on file about pregnancy or breastfeeding safety either way. Talk with your doctor or pharmacist for personalized advice before starting.
What are the most common side effects?
Melatonin commonly causes dizziness, drowsiness, headache, and nausea. 5-HTP adds stomach pain, diarrhea, fatigue, and insomnia to that list. Many of these side effects can depend on the dose and may ease with continued use, especially for 5-HTP's stomach issues.
Will this really help me sleep better?
Melatonin is likely effective if you have non-24-hour sleep-wake disorder or delayed sleep phase syndrome—specific timing disorders. For general insomnia or sleep support, the evidence is weaker. 5-HTP is possibly effective for depression, which sometimes improves sleep indirectly, but that's less direct.
How long can I safely take this?
Melatonin is generally well tolerated for short-term use, but long-term safety is less certain. 5-HTP is also generally well tolerated short-term. We'd recommend talking with your doctor about how long is right for you personally.
What's the difference between the two ingredients—why are they together?
Melatonin regulates your sleep-wake cycle and signals your body it's time to rest. 5-HTP is a building block for serotonin, which affects mood and also plays a role in sleep. Together, they're meant to support both sleep timing and the mood side of rest, though the evidence for 5-HTP for mood is still developing.

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

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

5-HTP & Melatonin label
Go deeper

The Full Monographs Behind 5-HTP & Melatonin’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Melatonin

Interacts with 1,461 drugs

Melatonin is a hormone your body makes naturally to help control your sleep-wake cycle, and the supplement form is widely used to help with sleep timing problems and jet lag. The evidence is...

Read the full Melatonin monograph → Herb & supplement monograph

5-htp

Interacts with 398 drugs

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 evide...

Read the full 5-htp monograph →
Sources

Sources & How We Checked

5-HTP & Melatonin's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 150 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Melatonin 118 references
  1. Voordouw BC, Euser R, Verdonk RE, et al. Melatonin and melatonin-progestin combinations alter pituitary-ovarian function in women and can inhibit ovulation. J Clin Endocrinol Metab 1992;74:108-17. DOI
  2. Ellis CM, Lemmens G, Parkes JD. Melatonin and insomnia. J Sleep Res 1996;5:61-5. PubMed
  3. Petrie K, Dawson AG, Thompson L, Brook R. A double-blind trial of melatonin as a treatment for jet lag in international cabin crew. Biol Psychiatr 1993;33:526-30. PubMed
  4. Claustrat B, Brun J, David M, et al. Melatonin and jet lag: confirmatory result using a simplified protocol. Biol Psychiatr 1992;32:705-11.
  5. Fauteck J, Schmidt H, Lerchl A, et al. Melatonin in epilepsy: first results of replacement therapy and first clinical results. Biol Signals Recept 1999;8:105-10. PubMed
  6. Arangino S, Cagnacci A, Angiolucci M, et al. Effects of melatonin on vascular reactivity, catecholamine levels, and blood pressure in healthy men. Am J Cardiol 1999;83:1417-9. PubMed
  7. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  8. Lancioni GE, O'Reilly MF, Basili G. Review of strategies for treating sleep problems in persons with severe or profound mental retardation or multiple handicaps. Am J Ment Retard 1999;104:170-86. PubMed
  9. Carman JS, Post RM, Buswell R, et al. Negative effects of melatonin on depression. Am J Psychiatry 1976;133:1181-1186. PubMed
  10. Hartter S, Grozinger M, Weigmann H, et al. Increased bioavailability of oral melatonin after fluvoxamine coadministration. Clin Pharmacol Ther 2000;67:1-6.
  11. Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
  12. Lusardi P, et al. Cardiovascular effects of melatonin in hypertensive patients well controlled by nifedipine: a 24-hour study. Br J Clin Pharmacol 2000;49:423-7. PubMed
  13. von Bahr C, Ursing C, Yasui N, et al. Fluvoxamine but not citalopram increases serum melatonin in healthy subjects – an indication that cytochrome P450 CYP1A2 and CYP2C19 hydroxylate melatonin. Eur J Clin Pharmacol 2000;56:123-7.
  14. Grozinger M, Hartter S, Wang X, et al. Fluvoxamine strongly inhibits melatonin metabolism in a patient with low-amplitude melatonin profile. Arch Gen Psychiatry 2000 Aug;57:812-3. PubMed
  15. Lissoni P, Barni S, Mandala M, et al. Decreased toxicity and increased efficacy of cancer chemotherapy using the pineal hormone melatonin in metastatic solic tumor patients with poor clinical status. Eur J Cancer 1999;35:1688-92.
  16. Sheldon SH. Pro-convulsant effects of oral melatonin in neurologically disabled children. Lancet 1998;351:1254. PubMed
  17. Hartter S, Grozinger M, Weigmann H, et al. Increased bioavailability of oral melatonin after fluvoxamine coadministration. Clin Pharmacol Ther 2000;67:1-6.
  18. Wright KP Jr, Myers BL, Plenzler SC, et al. Acute effects of bright light and caffeine on nighttime melatonin and temperature levels in women taking and not taking oral contraceptives. Brain Res 2000;873:310-7.
  19. Herxheimer A, Petrie KJ. Melatonin for preventing and treating jet lag. Cochrane Database Syst Rev 2001;(1):CD001520.
  20. Briggs, Freeman, Yafee. Update Drugs in Pregnancy and Lactation. Lippincott Williams & Wilkins, 2001.
  21. Suhner A, Schlagenhauf P, Johnson R, et al. Comparative study to determine the optimal melatonin dosage form for the alleviation of jet lag. Chronobiol Int 1998;15:655-66. PubMed
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