L-Tryptophan Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Tryptophan 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
L-Tryptophan is a dietary supplement by Thorne Research with 1 active ingredient. Its ingredients are commonly taken for sleep problems, low mood and depression, anxiety.Based on those ingredients, 394 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are L-Tryptophan. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against L-Tryptophan by Thorne Research
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Tryptophan by Thorne Research — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
Ask the Pharmacist
A licensed pharmacist will answer your question by email — free, usually within 24 hours.
Got it — thank you!
A licensed pharmacist will answer within 24 hours. Keep an eye on your email (worth checking spam, just in case).
HelloPharmacist Scorecard of L-Tryptophan by Thorne Research
Four independent checks of what is known — a summary of the available information, not a grade of the product itself.
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
The stated purpose hasn't been mapped to our evidence data yet.
Why this rating?
- We haven't mapped this product's purpose to our evidence data yet — it'll be graded on the next content refresh.
Every active ingredient lists its own amount on the label.
Why this rating?
- The label discloses an exact amount for 1 of its 1 active ingredient.
- No proprietary blends here — you can verify the dose of every single component.
At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.
Why this rating?
- 1 of the 1 matched ingredient can interact with medications — L-tryptophan.
- The most serious interaction on file is rated Major.
- For scale: 394 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.
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 1 of the 1 matched ingredient.
- Pregnancy & breastfeeding safety ratings cover 1 of 1.
- General safety write-ups exist for 1 of 1.
- Remember: this measures how much safety information exists. Thin data is not the same as being safe.
HelloPharmacist summaryFully disclosed formula with no assessable stated purpose. Major medication interactions have been identified, and safety information is well characterized.
Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Nov 21, 2012.
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
General information
Key facts about L-Tryptophan, straight from the product label.
| Brand | Thorne Research |
|---|---|
| Barcode (UPC) | 693749501015 |
| Net contents | 60 Vegetarian Capsule(s) |
| Market status | Off market |
| Date entered into DSLD | Nov 21, 2012 |
| DSLD ID | 15966 |
| Product type | Amino Acid/protein |
| Supplement form | Capsule |
| Dietary claims / uses | All Other |
| Intended target group(s) | Adult (18 - 50 Years), No Allergies |
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 L-Tryptophan by Thorne Research, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Tryptophan | 1 g | -- |
Other ingredients: Hypromellose (derived from Cellulose) Capsule, Leucine, Microcrystalline Cellulose, Silicon Dioxide
Tap any ingredient to jump to its full detail below.
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.
FDA Statement of Identity
DIETARY SUPPLEMENT
Suggested/Recommended/Usage/Directions
Suggested Use: Take 1-2 capsules two times daily or as recommended by your health-care practitioner.
Precautions
Tamper Evident: Use only if bottle is sealed.
If pregnant, consult your health-care practitioner before using this product.
Storage
Store tightly sealed in a cool, dry place.
Seals/Symbols
(pulled apart capsule)(R)
Formula
HYPOALLERGENIC
General
SA501 LSA50106
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Tryptophan by Thorne Research label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in L-Tryptophan by Thorne Research
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.
L-Tryptophan
Interacts with394 drugs
L-tryptophan is an essential amino acid the body uses to make serotonin and melatonin, and people take it to support sleep and mood. The evidence for...
L-Tryptophan monograph & interactionsOther (inactive) ingredients: Hypromellose (derived from Cellulose) Capsule, Leucine, Microcrystalline Cellulose, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.
L-Tryptophan by Thorne Research Drug Interactions
L-Tryptophan contains a single active ingredient, and it has known interactions with 394 medications. Here’s the picture, then you can look up your own drug.
Want to check YOUR meds against L-Tryptophan?
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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in L-Tryptophan interact with 394 drugs. Click any drug to see the details.
1 of the 1 ingredient in L-Tryptophan interact with drugs. Each result below shows which ingredient is responsible. L-Tryptophan
Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan HbrVicks Formula 44M Cough, Cold & Flu Relief
How Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan Hbr interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan Hbr interactionAcetaminophen, Chlorpheniramine, DextromethorphanCoricidin II Extra Strength Cold and Flu
How Acetaminophen, Chlorpheniramine, Dextromethorphan interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Dextromethorphan interactionAcetaminophen, Chlorpheniramine, Dextromethorphan HydrobromideCoricidin HBP Maximum Strength Flu
How Acetaminophen, Chlorpheniramine, Dextromethorphan Hydrobromide interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Dextromethorphan Hydrobromide interactionAcetaminophen, Chlorpheniramine, Dextromethorphan, PhenylpropanolamineMulti Symptom Cold Relief
How Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylpropanolamine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylpropanolamine interactionAcetaminophen, Chlorpheniramine, Dextromethorphan, PseudoephedrineChildren's Tylenol Cold Plus Cough, Tylenol Cold Ex Strength
How Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine interactionAcetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, SalicylamideRhinogesic GG
How Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, Salicylamide interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, Salicylamide interactionAcetaminophen, Chlorpheniramine, PhenylephrineAlka-Seltzer PLUS, Histex SR, Protid
How Acetaminophen, Chlorpheniramine, Phenylephrine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Phenylephrine interactionAcetaminophen, Chlorpheniramine, Phenylephrine, SalicylamideRhinogesic, Rhinogesic JR
How Acetaminophen, Chlorpheniramine, Phenylephrine, Salicylamide interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Phenylephrine, Salicylamide interactionAcetaminophen, Chlorpheniramine, PhenylpropanolamineAlumadrine, Conex, Sinadrin Max Strength, Sinulin
How Acetaminophen, Chlorpheniramine, Phenylpropanolamine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Phenylpropanolamine interactionAcetaminophen, Chlorpheniramine, Phenylpropanolamine, PhenyltoloxamineNorel Plus
How Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Phenyltoloxamine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Phenyltoloxamine interactionAcetaminophen, Chlorpheniramine, PseudoephedrineAlka-Seltzer PLUS Liquid Gels, Children's Tylenol Cold, Codimal, Comtrex, Extra Strength Tylenol Allergy Sinus, Lorsin +3 more
How Acetaminophen, Chlorpheniramine, Pseudoephedrine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Pseudoephedrine interactionAcetaminophen, DextromethorphanTylenol Cough Ex Strength
How Acetaminophen, Dextromethorphan interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Dextromethorphan interactionAcetaminophen, Dextromethorphan, Doxylamine, PseudoephedrineVicks NyQuil
How Acetaminophen, Dextromethorphan, Doxylamine, Pseudoephedrine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Dextromethorphan, Doxylamine, Pseudoephedrine interactionAcetaminophen, Dextromethorphan, Guaifenesin, PhenylephrineConar-A
How Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine interactionAcetaminophen, Dextromethorphan, Guaifenesin, PhenylpropanolamineAnatuss
How Acetaminophen, Dextromethorphan, Guaifenesin, Phenylpropanolamine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Dextromethorphan, Guaifenesin, Phenylpropanolamine interactionAcetaminophen, Dextromethorphan, Guaifenesin, PseudoephedrineRobitussin Cold, Severe Cold, Suphedrine Cold/Cough
How Acetaminophen, Dextromethorphan, Guaifenesin, Pseudoephedrine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Dextromethorphan, Guaifenesin, Pseudoephedrine interactionAcetaminophen, Dextromethorphan, Phenylpropanolamine, PyrilamineTheracaps
How Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Dextromethorphan, Phenylpropanolamine, Pyrilamine interactionAcetaminophen, Dextromethorphan, PseudoephedrineAlka-Seltzer PLUS Flu Liquid Gels, Non Aspirin Cold Caps, Tylenol Cold, Tylenol Flu Daytime Ex Strength, Tylenol Flu Ex Strength
How Acetaminophen, Dextromethorphan, Pseudoephedrine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Dextromethorphan, Pseudoephedrine interactionAcetaminophen, Phenylephrine, ChlorpheniramineSuper Cold Tabs
How Acetaminophen, Phenylephrine, Chlorpheniramine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Phenylephrine, Chlorpheniramine interactionAlmotriptanAlmogran, Axert
How Almotriptan interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Almotriptan interactionAlosetronLotronex
How Alosetron interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Alosetron interactionAmoxapineAsendin
How Amoxapine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Amoxapine interactionAmphetamine Aspartate, Amphetamine Sulfate, Dextroamphetamine Saccharate, Dextroamphetamine SulfateAdderall, Adderall XR
How Amphetamine Aspartate, Amphetamine Sulfate, Dextroamphetamine Saccharate, Dextroamphetamine Sulfate interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Amphetamine Aspartate, Amphetamine Sulfate, Dextroamphetamine Saccharate, Dextroamphetamine Sulfate interactionAspirin, Chlorpheniramine, PhenylpropanolamineAlka-Seltzer Plus Cold
How Aspirin, Chlorpheniramine, Phenylpropanolamine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Aspirin, Chlorpheniramine, Phenylpropanolamine interactionAtropine, Benzoic Acid, Hyoscyamine, Methenamine, Methylene Blue, PhenylAtrosept
How Atropine, Benzoic Acid, Hyoscyamine, Methenamine, Methylene Blue, Phenyl interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Atropine, Benzoic Acid, Hyoscyamine, Methenamine, Methylene Blue, Phenyl interactionAtropine, Benzoic Acid, Hyoscyamine, Methenamine, Methylene Blue, Phenyl SalicylateUrinary Antiseptic 2, Urised
How Atropine, Benzoic Acid, Hyoscyamine, Methenamine, Methylene Blue, Phenyl Salicylate interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Atropine, Benzoic Acid, Hyoscyamine, Methenamine, Methylene Blue, Phenyl Salicylate interactionAtropine, Chlorpheniramine, Hyoscyamine, Phenylephrine, Phenylpropanolamine, ScopolamineAtrohist Plus, Pro Tuss, Ru-tuss, Stahist
How Atropine, Chlorpheniramine, Hyoscyamine, Phenylephrine, Phenylpropanolamine, Scopolamine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Atropine, Chlorpheniramine, Hyoscyamine, Phenylephrine, Phenylpropanolamine, Scopolamine interactionBelladonna Alkaloids, Chlorpheniramine, Phenylephrine, PhenylpropanolamineRespa ARM
How Belladonna Alkaloids, Chlorpheniramine, Phenylephrine, Phenylpropanolamine interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Belladonna Alkaloids, Chlorpheniramine, Phenylephrine, Phenylpropanolamine interactionBenzocaine, DextromethorphanTetra-Formula
How Benzocaine, Dextromethorphan interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Benzocaine, Dextromethorphan interactionBrexpiprazoleRexulti
How Brexpiprazole interacts with L-Tryptophan — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs Moderate
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Brexpiprazole interactionEach ingredient & the kinds of drugs it affects
For each ingredient in L-Tryptophan with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.
L-Tryptophan
Cns Depressants
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Clinical research shows that L-tryptophan can cause fatigue and drowsiness.
Serotonergic Drugs
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
L-tryptophan is a precursor to serotonin. Theoretically, combining serotonergic drugs with L-tryptophan might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders.
Brand information
Manufacturer and brand details for L-Tryptophan, from the product label.
Thorne Research
See all Thorne Research products- Name
- Thorne Research, Inc.
- Street Address
- P.O. Box 25
- City
- Dover
- State
- Idaho
- ZipCode
- 83825
- Phone Number
- 1-800-228-1966
- Web Address
- www.thorne.com
L-Tryptophan by Thorne Research: Common Questions
Does L-Tryptophan by Thorne Research interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Tryptophan is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
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.
The Full Monographs Behind L-Tryptophan’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Sources & How We Checked
L-Tryptophan'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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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 18 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.
L-tryptophan 18 references
- Messiha FS. Fluoxetine: adverse effects and drug-drug interactions. J Toxicol Clin Toxicol 1993;31:603-30. PubMed
- Devoe LD, Castillo RA, Searle NS. Maternal dietary substrates and human fetal biophysical activity. The effects of tryptophan and glucose on fetal breathing movements. Am J Obstet Gynecol 1986;155:135-9. DOI
- Lieberman HR, Corkin S, Spring BJ. The effects of dietary neurotransmitter precursors on human behavior. Am J Clin Nutr 1985;42:366-70. PubMed
- 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.
- Sullivan EA, Kamb ML, Jones JL, et al. The natural history of eosinophilia-myalgia syndrome in a tryptophan-exposed cohort in South Carolina. Arch Intern Med 1996;156:973-9. DOI
- Philen RM, Hill RH, Flanders WD, et al. Tryptophan contaminants associated with eosinophilia-myalgia syndrome. Am J Epidemiol 1993;138:154-9. PubMed
- Bohme A, Wolter M, Hoelzer D. L-tryptophan-related eosinophilia-myalgia syndrome possibly associated with a chronic B-lymphocytic leukemia. Ann Hematol 1998;77:235-8. PubMed
- Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
- Priori R, Conti F, Luan FL, et al. Chronic fatigue: a peculiar evolution of eosinophilia myalgia syndrome following treatment with L-tryptophan in four Italian adolescents. Eur J Pediatr 1994;153:344-6..
- Klein R, Berg PA. A comparative study on antibodies to nucleoli and 5-hydroxytryptamine in patients with fibromyalgia syndrome and tryptophan-induced eosinophilia-myalgia syndrome. Clin Investig 1994;72:541-9.. PubMed
- Simat TJ, Kleeberg KK, Muller B, Sierts A. Synthesis, formation, and occurrence of contaminants in biotechnologically manufactured L-tryptophan. Adv Exp Med Biol 1999;467:469-80.. PubMed
- Shaw K, Turner J, Del Mar C. Tryptophan and 5-hydroxytryptophan for depression. Cochrane Database Syst Rev 2002;(1):CD003198. PubMed
- Kilbourne EM, Philen RM, Kamb ML, Falk H. Tryptophan produced by Showa Denko and epidemic eosinophilia-myalgia syndrome. J Rheumatol Suppl 1996;46:81-8.
- Horwitz RI, Daniels SR. Bias or biology: evaluating the epidemiologic studies of L-tryptophan and the eosinophilia-myalgia syndrome. J Rheumatol Suppl 1996;46:60-72.
- Shapiro S. Epidemiologic studies of the association of L-tryptophan with the eosinophilia-myalgia syndrome: a critique. J Rheumatol Suppl 1996;46:44-58.
- Mayeno AN, Gleich GJ. The eosinophilia-myalgia syndrome: lessons from Germany. Mayo Clin Proc 1994;69:702-4. PubMed
- Carr L, Ruther E, Berg PA, Lehnert H. Eosinophilia-myalgia syndrome in Germany: an epidemiologic review. Mayo Clin Proc 1994;69:620-5. PubMed
- Ullrich SS, Fitzgerald PCE, Giesbertz P, Steinert RE, Horowitz M, Feinle-Bisset C. Effects of intragastric administration of tryptophan on the blood glucose response to a nutrient drink and energy intake, in lean and obese men. Nutrients 2018;10(4). pii: PubMed
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.
© 2021 Therapeutic Research Center, LLC