L-Tryptophan (250 mg) Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Tryptophan (250 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
L-Tryptophan (250 mg) is a dietary supplement by BulkSupplements.com 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 (250 mg) by BulkSupplements.com
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Tryptophan (250 mg) by BulkSupplements.com — 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 (250 mg) by BulkSupplements.com
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.
What’s inside
Full disclosure
This product contains one active ingredient: L-Tryptophan at 250 mg per capsule. L-Tryptophan is an amino acid — one of the building blocks your body uses to make proteins and neurotransmitters, including serotonin, which plays a role in mood and sleep.
The capsule itself is made from bovine gelatin (an inactive ingredient).
Does it work?
Couldn't assess
The evidence on L-Tryptophan for the uses listed is limited. For depression, the data suggests it's possibly ineffective.
For anxiety, athletic performance, teeth grinding (bruxism), and premenstrual dysphoric disorder, there isn't enough reliable evidence yet to know whether it works or not.
How safe is it?
Well-documented data
L-Tryptophan is generally well tolerated when taken by mouth. The most common side effects are mild — belching, diarrhea, drowsiness, dry mouth, flatulence, headache, heartburn, lightheadedness, nausea, stomach pain, blurred vision, and vomiting.
The supplement does come with a historical caution: in 1989, a contaminated batch from a single Japanese manufacturer was linked to over 1,500 cases of a rare neurological disorder called eosinophilia-myalgia syndrome (EMS); modern supplies are subject to stricter controls, but this history warrants awareness. During pregnancy, the safety data is mixed — one rating suggests it's possibly unsafe, so the data advises against it.
While breastfeeding, there isn't enough safety information, so it's best avoided. Talk to your doctor or pharmacist before using L-Tryptophan if you're pregnant, planning to become pregnant, or breastfeeding.
Meds to double-check
Major interaction found
Before taking L-Tryptophan, double-check with your doctor or pharmacist if you take any central nervous system depressants (sedatives, sleeping pills, opioids, or alcohol) or serotonergic medications (antidepressants, migraine drugs, or other drugs that affect serotonin). The interaction checker on this page can help you screen your specific medications.
The bottom line
Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Major medication interactions have been identified, and safety information is well characterized.
L-Tryptophan is a single amino acid that may be worth considering if you're interested in mood or sleep support, though the evidence for depression is weak and for other uses is still uncertain. The main caution is interaction with sedating drugs and serotonin-based medications — if you take any of those, you'll need to check with your doctor or pharmacist first.
It's not recommended in pregnancy or while breastfeeding. Talk it over with your own healthcare provider before starting.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Sep 24, 2021.
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 (250 mg), straight from the product label.
| Brand | BulkSupplements.com |
|---|---|
| Net contents | 300 Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Sep 24, 2021 |
| DSLD ID | 254831 |
| Product type | Amino Acid/protein |
| Supplement form | Capsule |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Gluten Free, Dairy Free |
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 (250 mg) by BulkSupplements.com, sourced from the NIH Dietary Supplement Label Database.
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.
General Statements
Clean & pure bulk supplements
FDA Disclaimer Statement
Warning: This product is not intended to diagnose, treat, cure, or prevent any disease.
Precautions
Always consult a physician before taking any dietary supplement.
Keep out of reach of children.
Formulation
Free of: Added sugar, soy, dairy, yeast, gluten, additives
Suggested/Recommended/Usage/Directions
Suggested use: As a dietary supplement, take 2 capsules once or twice daily, or as directed by a physician.
Storage
Store in a dry, cool place
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Tryptophan (250 mg) by BulkSupplements.com 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 (250 mg) by BulkSupplements.com
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size2 Capsule(s) Dosage formCapsule Servings per container150 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: Bovine Gelatin. These complete the product’s ingredient list but are not active constituents.
L-Tryptophan (250 mg) by BulkSupplements.com Drug Interactions
HelloPharmacist Interaction Report
L-Tryptophan by BulkSupplements.com interacts with two major drug categories through its amino acid content.
The most serious concern is with central nervous system depressants (CNS depressants) — drugs that slow brain activity like sedatives, sleeping pills, and opioids. L-Tryptophan can add to their drowsy, sedative effects, which the research shows it causes on its own.
Read the full breakdown — every affected drug type, severity by severity
The second interaction involves serotonergic drugs — medications that work through the neurotransmitter serotonin, such as antidepressants (including SSRIs and SNRIs), migraine drugs, and certain other psychiatric medications. L-Tryptophan is a building block for serotonin in your body.
Combining it with these drugs might amplify serotonin activity and raise the risk of serotonin syndrome (a potentially serious condition marked by agitation, rapid heartbeat, muscle rigidity, and high fever) or blood-vessel constriction in the brain.
Although the exact number of individual medications affected is large — 394 total — the main drug types to watch are the ones listed above. Before you start L-Tryptophan, run any sedatives, sleeping aids, opioids, antidepressants, or serotonin-related medications through the interaction checker on this page, or talk to your doctor or pharmacist.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Tryptophan (250 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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in L-Tryptophan (250 mg) interact with 394 drugs. Click any drug to see the details.
1 of the 1 ingredient in L-Tryptophan (250 mg) interact with drugs. Each result below shows which ingredient is responsible. L-Tryptophan
AcepromazineAtravet
How Acepromazine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acepromazine interactionAcetaminophen, Butalbital, Caffeine, CodeineEsgic with Codeine, Fioricet w/ Codeine
How Acetaminophen, Butalbital, Caffeine, Codeine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Butalbital, Caffeine, Codeine interactionAcetaminophen, Butalbital, CodeineBancap w/ Codeine
How Acetaminophen, Butalbital, Codeine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Butalbital, Codeine interactionAcetaminophen, Butalbital, Codeine PhosphatePhrenilin #3
How Acetaminophen, Butalbital, Codeine Phosphate interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Butalbital, Codeine Phosphate interactionAcetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound
How Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interactionAcetaminophen, Caffeine, CodeineGesic C15, Gesic C30, Gesic C8, Lenoltec 1, Lenoltec 2, Lenoltec 3 +1 more
How Acetaminophen, Caffeine, Codeine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Caffeine, Codeine interactionAcetaminophen, Caffeine, Codeine, SalicylamideCodalan No.1, Codalan No.2, Codalan No.3
How Acetaminophen, Caffeine, Codeine, Salicylamide interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Caffeine, Codeine, Salicylamide interactionAcetaminophen, Caffeine, DihydrocodeineDHC Plus, Panlor DC, Panlor SS
How Acetaminophen, Caffeine, Dihydrocodeine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Caffeine, Dihydrocodeine interactionAcetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex
How Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs, Cns Depressants Major
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interactionAcetaminophen, Chlorpheniramine, Phenylpropanolamine, OpiumHista-Derfule
How Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Opium interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanSerotonergic Drugs, Cns Depressants Major
Interaction Summary
Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
Read the full L-tryptophan + Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Opium interactionAcetaminophen, Chlorzoxazone, CodeineAcetazone Forte C8, Parafon Forte C8
How Acetaminophen, Chlorzoxazone, Codeine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Chlorzoxazone, Codeine interactionAcetaminophen, CodeineTylenol No.3, Tylenol w/ Codeine
How Acetaminophen, Codeine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Codeine interactionAcetaminophen, Codeine, DoxylamineMersyndol
How Acetaminophen, Codeine, Doxylamine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Codeine, Doxylamine interactionAcetaminophen, Codeine, MethocarbamolAcetaminophen, Codeine, Methocarbamol, Robaxacet 8
How Acetaminophen, Codeine, Methocarbamol interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Codeine, Methocarbamol interactionAcetaminophen, Dichloralantipyrine, IsomethepteneAmidrine, Midchlor, Migquin, Migratine
How Acetaminophen, Dichloralantipyrine, Isometheptene interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Dichloralantipyrine, Isometheptene interactionAcetaminophen, Dichloralphenazone, IsomethepteneMidrin
How Acetaminophen, Dichloralphenazone, Isometheptene interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Dichloralphenazone, Isometheptene interactionAcetaminophen, Dichlorophenazone, IsometheptaneIsocom
How Acetaminophen, Dichlorophenazone, Isometheptane interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Dichlorophenazone, Isometheptane interactionAcetaminophen, DiphenhydramineTylenol PM, Tylenol PM Ex Strength
How Acetaminophen, Diphenhydramine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Diphenhydramine interactionAcetaminophen, Diphenhydramine, PseudoephedrineChildren's Tylenol Allergy, Cold Control, Contac Night Allergy Relief
How Acetaminophen, Diphenhydramine, Pseudoephedrine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Diphenhydramine, Pseudoephedrine interactionAcetaminophen, HydrocodoneAnexsia, Anodynos DHC, Azdone, Co-Gesic, Doucet, Lorcet +9 more
How Acetaminophen, Hydrocodone interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Hydrocodone interactionAcetaminophen, MeperidineDemerol APAP
How Acetaminophen, Meperidine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants, Serotonergic Drugs Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Meperidine interactionAcetaminophen, OxycodonePercocet, Roxicet, Tylox, Xartemis XR
How Acetaminophen, Oxycodone interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Oxycodone interactionAcetaminophen, PentazocineTalacen
How Acetaminophen, Pentazocine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Pentazocine interactionAcetaminophen, PropoxypheneDarvocet-N 100, Darvocet-N 50, E-Lor, Wygesic
How Acetaminophen, Propoxyphene interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetaminophen, Propoxyphene interactionAcetazolamideAk-Zol, Diamox
How Acetazolamide interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Acetazolamide interactionAlfentanilAlfenta
How Alfentanil interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Alfentanil interactionAlprazolamNiravam, Xanax
How Alprazolam interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Alprazolam interactionAluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #2
How Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interactionAminoglutethimideCytadren
How Aminoglutethimide interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Aminoglutethimide interactionAminophylline, Amobarbital, EphedrineAmesec
How Aminophylline, Amobarbital, Ephedrine interacts with L-Tryptophan (250 mg) — through 1 ingredient. Tap an ingredient for the detail:
L-tryptophanCns Depressants Major
Interaction Summary
Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Read the full L-tryptophan + Aminophylline, Amobarbital, Ephedrine interactionEach ingredient & the kinds of drugs it affects
For each ingredient in L-Tryptophan (250 mg) 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 (250 mg), from the product label.
BulkSupplements.com
See all BulkSupplements.com products- Name
- BulkSupplements.com
- Street Address
- 7511 Eastgate Rd
- City
- Henderson
- State
- NV
- ZipCode
- 89011
- Web Address
- BulkSupplements.com
L-Tryptophan (250 mg) by BulkSupplements.com: Common Questions
Does L-Tryptophan (250 mg) by BulkSupplements.com interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
What is L-Tryptophan, and what does it do?
Does L-Tryptophan actually help with depression or sleep?
What are the common side effects?
Is L-Tryptophan safe? I've heard about a contamination scare.
Can I take L-Tryptophan while pregnant or breastfeeding?
Will it interact with my antidepressant or sleeping pill?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Tryptophan (250 mg) 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 (250 mg)’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 (250 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.
- 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