Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

5-HTP 100 mg Ingredients & Drug Interactions

by NutraFitz Naturals

5-HTP 100 mg label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking 5-HTP 100 mg 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 100 mg is a dietary supplement by NutraFitz Naturals with 3 active ingredients. Its ingredients are commonly taken for low mood or depression, anxiety and stress, sleep problems.Based on those ingredients, 572 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are 5-HTP, Vitamin B6. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against 5-HTP 100 mg by NutraFitz Naturals

Ask about any prescription or over-the-counter medication and we check it for interactions with 5-HTP 100 mg by NutraFitz Naturals — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of 5-HTP 100 mg by NutraFitz Naturals

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 3 of its 3 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains 3 active ingredients. The main one is 5-HTP, an amino acid your body uses to make serotonin, a chemical that affects mood and sleep.

It also contains vitamin B6, which supports nerve function and helps your body use proteins. The third active ingredient is organic sunflower lecithin, a fat that may support cell function.

The capsule itself is made from vegetable cellulose, and the powder inside includes organic brown rice flour as a filler.

Does it work?

Moderate 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: supports well-being and sleep.
  • We looked for evidence on: Anxiety, Depression, Fibromyalgia, Insomnia, Migraine headache, Panic disorder — and 4 related terms.
  • The strongest evidence on file: 5-htp is rated "Possibly Effective" for Depression (Natural Medicines).
  • Also on file: 5-htp is rated "Insufficient Reliable Evidence To Rate" for Anxiety, Migraine headache, Fibromyalgia, Insomnia, and more.
  • Also on file: Vitamin B6 is rated "Insufficient Reliable Evidence To Rate" for Anxiety.

5-HTP is possibly effective for depression based on available evidence, though the data we hold doesn't rate it for panic disorder, cerebellar ataxia, or Alzheimer's disease—the evidence simply isn't established enough to say. It appears possibly ineffective for Down syndrome.

Vitamin B6 in this product is effective for vitamin B6 deficiency and sideroblastic anemia, likely effective for high homocysteine levels, and possibly effective for pregnancy-related nausea and vomiting—though if you're pregnant, you'd need to discuss it with your doctor first. Sunflower lecithin is likely ineffective for Alzheimer's disease; evidence for other uses like age-related cognitive decline isn't established in the data we hold.

The evidence, ingredient by ingredient 5-htp Vitamin B6 Lecithin

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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

5-HTP is generally well tolerated short-term, though common side effects include abdominal pain, nausea, diarrhea, drowsiness, dizziness, headache, and insomnia—most are dose-dependent and may improve with continued use. Rare serious effects include aggression, hallucinations, and mania.

Do not use during pregnancy or breastfeeding; safety data is not available. Vitamin B6 below 100 mg daily is well tolerated; at higher doses taken long-term, it can damage nerves (sensory neuropathy).

Common side effects are headache, nausea, and heartburn. It's likely safe in pregnancy and lactation at recommended levels.

Sunflower lecithin is well tolerated and likely safe in pregnancy and lactation; those with egg or soy allergies should be cautious, as it may cause allergic skin reactions.

Side effects, ingredient by ingredient 5-htp Vitamin B6 Lecithin

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 3 matched ingredients can interact with medications — 5-htp, Vitamin B6.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: Parkinson's medications.
  • For scale: 572 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 you take this, check with us if you're on serotonergic drugs like antidepressants (SSRIs, SNRIs), tramadol, or migraine triptans—5-HTP can boost serotonin effects. Also flag sedating medications, blood pressure drugs, amiodarone for heart rhythm, seizure medications (phenytoin, phenobarbital), carbidopa for Parkinson's, and levodopa without carbidopa.

Use the medication checker on this page for your exact prescriptions.

Check your own medication Run your meds through the checker above

The bottom line

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

This product may help with depression, but because 5-HTP affects serotonin, it needs a careful medication check—especially if you take antidepressants, pain relievers, or migraine drugs. Talk to your pharmacist before starting, and avoid it entirely if you're pregnant or breastfeeding.

It's not for people taking seizure medications or heart medications without professional oversight.

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

Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jul 23, 2020.

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 100 mg, straight from the product label.

Brand NutraFitz Naturals
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Jul 23, 2020
DSLD ID 229280
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free
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 100 mg by NutraFitz Naturals, 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
120
IngredientAmount% DV
5-HTP100 mg--
Vitamin B67 mg412%
organic Sunflower Lecithin25 mg--

Other ingredients: Vegetable Cellulose Capsule, organic Brown Rice Flour

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: Take 1 capsule daily, with or without food on an empty stomach, or as recommended by a healthcare professional.

Precautions

Caution: Do not exceed recommended dose.

Pregnant and nursing mothers, children under the age of 18, and individuals with a known medical condition should consult a physician before taking this or any dietary supplement.

Pregnant and nursing mothers, children under the age of 18, and individuals with a known medical condition should consult a physician before taking this or any dietary supplement.

Formulation

No GMO, meat, dairy, eggs, wheat, gluten, soy, nuts, shellfish, binders & fillers, coloring, preservatives, gelatin, yeast.

Supports well-being & sleep

Helps manage appetite Formulated for enhanced absorption

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.

Seals/Symbols

GMP Good Manufacturing Practice Consistent Quality Made in the USA Manufactured at an FDA Registered Facility

Formula

Whole food griffonia simplicifolia

Vitamin B6 for serotonin conversion

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 100 mg by NutraFitz Naturals label

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

5-HTP 100 mg 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 100 mg by NutraFitz Naturals

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container120 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.

5-HTP

Interacts with
398 drugs
100 mg per serving Form: Griffonia simplicifolia

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...

5-HTP monograph & interactions

Vitamin B6

Interacts with
210 drugs
7 mg per serving Form: Pyridoxal 5-Phosphate

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is b...

Vitamin B6 monograph & interactions

Organic Sunflower Lecithin

No known
interactions
25 mg per serving

Lecithin is a natural fatty substance found in foods and made by the body that is widely used as a supplement and food emulsifier. Evidence supporting...

Organic Sunflower Lecithin monograph & interactions

Other (inactive) ingredients: Vegetable Cellulose Capsule, Organic Brown Rice Flour. These complete the product’s ingredient list but are not active constituents.

Interaction report

5-HTP 100 mg by NutraFitz Naturals Drug Interactions

Want to check YOUR meds against 5-HTP 100 mg?

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
572Drugs
570 Moderate 2 Minor

Ingredients driving the most interactions

5-HTP 398
Vitamin B6 210

Individual Drug Interactions

The ingredients in 5-HTP 100 mg interact with 572 drugs. Click any drug to see the details.

2 of the 3 ingredients in 5-HTP 100 mg interact with drugs. Each result below shows which ingredient is responsible. 5-HTP Vitamin B6

Each ingredient & the kinds of drugs it affects

For each ingredient in 5-HTP 100 mg 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.

5-HTP3 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
5-HTP full monograph & interactions

Vitamin B65 drug types · 210 drugs

Amiodarone (Cordarone)

Theoretically, vitamin B6 might increase the photosensitivity caused by amiodarone.
Despite initial case reports suggesting that pyridoxine may have a protective effect against amiodarone-induced photosensitivity, preliminary clinical research suggests that pyridoxine may actually exacerbate this adverse effect.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, vitamin B6 may have additive effects when used with antihypertensive drugs.
Research in hypertensive rats shows that vitamin B6 can decrease systolic blood pressure. Similarly, clinical research in patients with hypertension shows that taking high doses of vitamin B6 may reduce systolic and diastolic blood pressure, possibly by reducing plasma levels of epinephrine and norepinephrine.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

High doses of vitamin B6 may reduce the levels and clinical effects of phenobarbital.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenobarbital, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenobarbital to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Phenytoin (Dilantin)

High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenytoin, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenytoin to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Levodopa

Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.
Vitamin B6 (pyridoxine) enhances the metabolism of levodopa, reducing its clinical effects. However, this interaction does not occur when carbidopa is used concurrently with levodopa (Sinemet). Therefore, it is not likely to be a problem in most people.

Likelihood Unlikely Evidence D
Vitamin B6 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for 5-HTP 100 mg, from the product label.

NutraFitz Naturals

See all NutraFitz Naturals products
Name
NutraFitz
Street Address
318 W. Half Day Rd. Ste. 218
City
Buffalo Grove
State
IL
ZipCode
60089
Web Address
WWW.NUTRAFITZ.COM
Pharmacist Counseling Corner

5-HTP 100 mg by NutraFitz Naturals: Common Questions

Does 5-HTP 100 mg by NutraFitz Naturals interact with any medications?
Yes. Based on its ingredients, 5-HTP 100 mg has a known interaction with 572 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
5-HTP 100 mg contains 3 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 on an antidepressant?
Not without checking with your pharmacist first. 5-HTP raises serotonin, and combining it with antidepressants (which also raise serotonin) carries a moderate risk of serotonin syndrome—a serious condition with restlessness, rapid heart rate, high fever, and confusion. Your pharmacist needs to review your specific medication.
What are the most common side effects?
5-HTP commonly causes nausea, diarrhea, abdominal pain, drowsiness, dizziness, headache, and insomnia. Most of these are dose-dependent and often improve as your body adjusts. If you experience rare symptoms like hallucinations, aggression, or severe mood changes, stop and contact your doctor.
Is this safe during pregnancy or breastfeeding?
No. The safety data for 5-HTP isn't available for pregnancy or breastfeeding, so the facts recommend avoiding it in both. Vitamin B6 in the product is likely safe at normal doses during pregnancy and lactation, but the 5-HTP part makes this product not recommended. Talk to your doctor about safer options.
Will this actually help my depression?
The evidence shows 5-HTP is possibly effective for depression, meaning some people may benefit, but it's not a guarantee. Depression is complex and requires professional care—discuss with your doctor whether this supplement fits your treatment plan.
Does this contain any fillers or other ingredients I should know about?
The active ingredients are 5-HTP, vitamin B6, and organic sunflower lecithin. The capsule is vegetable cellulose, and there's organic brown rice flour as a filler. If you have an egg or soy allergy, be careful—lecithin can trigger allergic skin reactions in people with those allergies.
Why is there vitamin B6 in this product?
Vitamin B6 supports nerve function and helps your body use amino acids like 5-HTP. At the dose in this product (we'd need to see the label), it's well tolerated. Just know that very high doses of B6 over time can damage nerves, so don't exceed recommended amounts.

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 100 mg label
Go deeper

The Full Monographs Behind 5-HTP 100 mg’s Ingredients

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

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 → Herb & supplement monograph

Vitamin B6

Interacts with 210 drugs

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is best known for helping with pregnancy-rel...

Read the full Vitamin B6 monograph → Herb & supplement monograph

Lecithin

Lecithin is a natural fatty substance found in foods and made by the body that is widely used as a supplement and food emulsifier. Evidence supporting most of its health claims is limited, t...

Read the full Lecithin monograph →
Sources

Sources & How We Checked

5-HTP 100 mg'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 73 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.

5-htp 32 references
  1. Birdsall TC. 5-Hydroxytryptophan: A Clinically-Effective Serotonin Precursor. Altern Med Rev 1998;3:271-80.
  2. 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.
  3. 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
  4. U.S. Food and Drug Administration. Impurities confirmed in dietary supplement 5-hydroxy-L-tryptophan. FDA Talk Paper, August 31, 1998; T98-48.
  5. 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
  6. 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.
  7. 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.
  8. 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.
  9. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
  10. 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.
  11. 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
  12. 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
  13. den Boer JA, Westenberg HG. Behavioral, neuroendocrine, and biochemical effects of 5-hydroxytryptophan administration in panic disorder. Psychiatry Res 1990;31:267-78. PubMed
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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.
  19. 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
  20. 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
  21. Chase, T. N., Ng, L. K., and Watanabe, A. M. Parkinson's disease. Modification by 5-hydroxytryptophan. Neurology 1972;22(5):479-484.
  22. 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
  23. 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
  24. 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
  25. 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.
  26. 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.
  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. Das YT, Bagchi M, Bagchi D, Preuss HG. Safety of 5-hydroxy-L-tryptophan. Toxicol Lett 2004;150:111-22. PubMed
  29. Pardo JV. Mania following addition of hydroxytryptophan to monoamine oxidase inhibitor. Gen Hosp Psychiatry 2012;34(1):102.e13-4. PubMed
  30. 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.
  31. 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
  32. Maffei ME. 5-Hydroxytryptophan (5-HTP): Natural Occurrence, Analysis, Biosynthesis, Biotechnology, Physiology and Toxicology. Int J Mol Sci. 2020;22(1):181. PubMed

See these in context on the 5-htp monograph →

Vitamin B6 32 references
  1. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  2. Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
  3. Geerling BJ, Dagnelie PC, Badart-Smook A, et al. Diet as a risk factor for the development of ulcerative colitis. Am J Gastroenterol 2000;95:1008-13. PubMed
  4. South M. Neonatal seizures after pyridoxine use -- reply. Lancet 1999;354:2083. PubMed
  5. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  6. Baxter P, Aicardi J. Neonatal seizures after pyridoxine use. Lancet 1999;354:2082-3. PubMed
  7. Bendich A, Cohen M. Vitamin B6 safety issues. Ann N Y Acad Sci 1990;585:321-30.
  8. Schaumburg H, Kaplan J, Windebank A. Sensory neuropathy from pyridoxine abuse. A new megavitamin syndrome. N Engl J Med 1983;309:445-8. PubMed
  9. Gordon N. Pyridoxine dependency: an update. Dev Med Child Neurol 1997;39:63-5. PubMed
  10. Lewis PJ. Pain in the hand and wrist. Pyridoxine supplements may help patients with carpal tunnel syndrome. BMJ 1995;310:1534. PubMed
  11. Kaufman G. Pyridoxine against amiodarone-induced photosensitivity (letter). Lancet 1984;1:51-2. PubMed
  12. Mulrow JP, Mulrow CD, McKenna WJ. Pyridoxine and amiodarone-induced photosensitivity. Ann Intern Med 1985;103:68-9. PubMed
  13. Kawada A, Kashima A, Shiraishi H, et al. Pyridoxine-induced photosensitivity and hypophosphatasia. Dermatology 2000;201:356-60.. PubMed
  14. Vasile A, Goldberg R, Kornberg B. Pyridoxine toxicity: report of a case. J Am Osteopath Assoc 1984;83:790-1. DOI
  15. Hansson O, Sillanpaa M. Pyridoxine and serum concentration of phenytoin and phenobarbitone. Lancet 1976;1:256. DOI
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  20. de, Vogel S., Dindore, V., van, Engeland M., Goldbohm, R. A., van den Brandt, P. A., and Weijenberg, M. P. Dietary folate, methionine, riboflavin, and vitamin B-6 and risk of sporadic colorectal cancer. J Nutr 2008;138(12):2372-2378. PubMed
  21. Hagen, I., Nesheim, B. I., and Tuntland, T. No effect of vitamin B-6 against premenstrual tension. A controlled clinical study. Acta Obstet.Gynecol.Scand. 1985;64(8):667-670. PubMed
  22. Aybak, M., Sermet, A., Ayyildiz, M. O., and Karakilcik, A. Z. Effect of oral pyridoxine hydrochloride supplementation on arterial blood pressure in patients with essential hypertension. Arzneimittelforschung. 1995;45(12):1271-1273.
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See these in context on the Vitamin B6 monograph →

Lecithin 9 references
  1. Buchman AL, Dubin M, Jenden D, et al. Lecithin increases plasma free choline and decreases hepatic steatosis in long-term total parenteral nutrition patients. Gastroenterology 1992;102:1363-70.
  2. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  3. Chatellier G, Lacomblez L. Tacrine (tetrahydroaminoacridine; THA) and lecithin in senile dementia of the Alzheimer type: a multicentre trial. Groupe Francais d'Etude de la Tetrahydroaminoacridine. BMJ 1990;300:495-9.
  4. Gelenberg AJ, Dorer DJ, Wojcik JD, et al. A crossover study of lecithin treatment of tardive dyskinesia. J Clin Psychiatry 1990;51:149-53.
  5. Little A, Levy R, Chuaqui-Kidd P, Hand D. A double-blind, placebo controlled trial of high-dose lecithin in Alzheimer's disease. J Neurol Neurosurg Psychiatry 1985;48:736-42. PubMed
  6. Palm M, Moneret-Vautrin DA, Kanny G, et al. Food allergy to egg and soy lecithins. Allergy 1999;54:1116-7. PubMed
  7. Drachman DA, Glosser G, Fleming P, et al. Memory decline in the aged: treatment with lecithin and physostigmine. Neurology 1982;32:944-50. PubMed
  8. Gelenberg, A. J., Doller-Wojcik, J. C., and Growdon, J. H. Choline and lecithin in the treatment of tardive dyskinesia: preliminary results from a pilot study. Am J Psychiatry 1979;136(6):772-776. PubMed
  9. Electronic Code of Federal Regulations. Title 21, Chapter 1, Subchapter B, Part 184: Direct food substances affirmed as Generally Recognized as Safe. Subpart B - listing of specific substances affirmed as GRAS. Sec. 184.1400 Lecithin. Available at: https:

See these in context on the Lecithin monograph →

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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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