Double Strength L-Tryptophan 1000 mg Ingredients & Drug Interactions
by NOW
What is this page for?
First and foremost: checking Double Strength L-Tryptophan 1000 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
Double Strength L-Tryptophan 1000 mg is a dietary supplement by NOW 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 Double Strength L-Tryptophan 1000 mg by NOW
Ask about any prescription or over-the-counter medication and we check it for interactions with Double Strength L-Tryptophan 1000 mg by NOW — 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
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HelloPharmacist Scorecard of Double Strength L-Tryptophan 1000 mg by NOW
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 supplement contains one active ingredient: L-tryptophan 1000 mg per dose. L-tryptophan is an amino acid — a building block your body uses to make serotonin, a neurotransmitter involved in mood and sleep.
The product also contains inactive ingredients (binders and fillers like croscarmellose sodium, magnesium stearate, and silica) to hold the tablet together.
Does it work?
Not established
The evidence for L-tryptophan is mixed and limited. For depression, current data suggests it's possibly ineffective.
For anxiety, athletic performance, teeth grinding (bruxism), and premenstrual dysphoric disorder (PMDD), there isn't enough reliable evidence to rate whether it works. If you're considering this for any of those conditions, talk it over with your doctor first.
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, gas, headache, heartburn, lightheadedness, nausea, stomach pain, blurred vision, and vomiting.
Rarely, it has been linked to eosinophilia-myalgia syndrome (EMS), a serious neurological condition — but nearly all reported cases in the late 1980s came from contaminated L-tryptophan from a single Japanese manufacturer and prompted an FDA recall and import limits that have been in place since 1990. During pregnancy, the safety data is conflicting — some evidence suggests it's possibly unsafe, so it's best avoided.
While breastfeeding, there isn't enough safety information, so it should be avoided. Talk with your doctor or pharmacist about whether this supplement is right for you if you're pregnant, planning to become pregnant, or nursing.
Meds to double-check
Major interaction found
Before taking this product, check with your doctor or pharmacist if you're on CNS depressants (sedatives, sleep aids, opioids, or alcohol) — L-tryptophan may add to drowsiness. You should also confirm any serotonergic drugs you take, such as antidepressants (SSRIs, SNRIs), migraine medications, or certain pain relievers, because combining them with L-tryptophan could theoretically amplify serotonin-related side effects.
The bottom line
Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Major medication interactions have been identified, and safety information is well characterized.
NOW's Double Strength L-Tryptophan 1000 mg may be worth considering if you're interested in supporting mood or sleep and your doctor or pharmacist gives the go-ahead. If you take any sedating medications, antidepressants, migraine drugs, or other serotonergic medications, you'll need to clear it with your own healthcare provider first because of interaction risks.
Don't use it during pregnancy or while breastfeeding without talking to your doctor. Check your medications against the interaction tool on this page before you start.
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 Jun 20, 2024.
This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed
General information
Key facts about Double Strength L-Tryptophan 1000 mg, straight from the product label.
| Brand | NOW |
|---|---|
| Barcode (UPC) | 733739001696 |
| Net contents | 60 Tablet(s) |
| Market status | On market |
| Date entered into DSLD | Jun 20, 2024 |
| DSLD ID | 314285 |
| Product type | Amino Acid/protein |
| Supplement form | Tablet Or Pill |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Vegan, Vegetarian, Adult (18 - 50 Years), Kosher, Halal, Gluten 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 Double Strength L-Tryptophan 1000 mg by NOW, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Tryptophan | 1 Gram(s) | -- |
Other ingredients: Croscarmellose Sodium, Hydroxypropyl Cellulose, Stearic Acid, Magnesium Stearate, Hypromellose, Calcium Carbonate, Glycerin, 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.
Suggested/Recommended/Usage/Directions
Suggested Usage: Take 1 tablet 1 to 3 times daily on an empty stomach, with final dose at bedtime, or as directed by your physician.
Formula
Tryptophan is an essential amino acid; therefore, it is not synthesized by the body and must be obtained from the diet. Tryptophan is critical for the production of serotonin and melatonin, which help to support a positive mood, healthy sleep patterns, and proper immune system function.
Triangle K (Kosher)
NOW Double Strength L-Tryptophan has twice the L-Tryptophan (1000 mg per tablet) as in our regular strength product (500 mg per capsule).
Crescent H (Halal)
Formulation
Every lot of NOW L-Tryptophan is tested to be free of peak E and microbial contamination.
Supports relaxation Encourages positive mood Promotes restful sleep
Non-GMO
Vegetarian/Vegan
Made and quality tested in the USA with globally sourced ingredients.
Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or sesame ingredients.
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.
Precautions
Caution: For adults only. Keep out of reach of children.
Consult physician if pregnant/nursing, taking medication (especially antidepressants such as SSRIs and MAOIs), or have a medical condition.
May cause drowsiness. Do not use with alcoholic beverages or while operating heavy machinery.
Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or sesame ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.
Seals/Symbols
Triangle K (Kosher)
Crescent H (Halal) GMP Quality Assured
FDA Statement of Identity
A Dietary Supplement
General Statements
Amino Acids Family owned since 1968.
This bottle is made from 100% PCR (post-consumer recycled) resin.
Storage
Store in a cool, dry place after opening.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Double Strength L-Tryptophan 1000 mg by NOW 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 Double Strength L-Tryptophan 1000 mg by NOW
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 Tablet(s) Dosage formTablet Or Pill Servings per container60 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: Croscarmellose Sodium, Hydroxypropyl Cellulose, Stearic Acid, Magnesium Stearate, Hypromellose, Calcium Carbonate, Glycerin, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.
Double Strength L-Tryptophan 1000 mg by NOW Drug Interactions
HelloPharmacist Interaction Report
NOW's Double Strength L-Tryptophan 1000 mg can interact with medications through its single active ingredient, L-tryptophan.
The most serious interaction is with CNS depressants (sedatives, sleep aids, opioids, and similar drugs) — combining them with L-tryptophan may add to drowsiness and sedation because the supplement itself can cause fatigue and drowsiness.
Read the full breakdown — every affected drug type, severity by severity
L-tryptophan also interacts with serotonergic drugs (antidepressants like SSRIs, SNRIs, and others; migraine medications; and some pain relievers). Because L-tryptophan is a building block for serotonin, adding it to drugs that boost serotonin may amplify serotonergic effects, raising the theoretical risk of serotonin syndrome and narrowing of blood vessels in the brain.
Altogether, these interactions span 394 individual medications. Before you start this supplement, run through your exact prescriptions with the search tool 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 Double Strength L-Tryptophan 1000 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 Double Strength L-Tryptophan 1000 mg interact with 394 drugs. Click any drug to see the details.
1 of the 1 ingredient in Double Strength L-Tryptophan 1000 mg interact with drugs. Each result below shows which ingredient is responsible. L-Tryptophan
Dyphylline, Ephedrine, Guaifenesin, PhenobarbitalLufyllin-EPG
How Dyphylline, Ephedrine, Guaifenesin, Phenobarbital interacts with Double Strength L-Tryptophan 1000 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 + Dyphylline, Ephedrine, Guaifenesin, Phenobarbital interactionEphedrine, Guaifenesin, Phenobarbital, TheophyllineMudrane GG
How Ephedrine, Guaifenesin, Phenobarbital, Theophylline interacts with Double Strength L-Tryptophan 1000 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 + Ephedrine, Guaifenesin, Phenobarbital, Theophylline interactionEphedrine, Phenobarbital, Potassium Iodide, TheophyllineMudrane, Quadrinal
How Ephedrine, Phenobarbital, Potassium Iodide, Theophylline interacts with Double Strength L-Tryptophan 1000 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 + Ephedrine, Phenobarbital, Potassium Iodide, Theophylline interactionEphedrine, Phenobarbital, TheophyllineTedral
How Ephedrine, Phenobarbital, Theophylline interacts with Double Strength L-Tryptophan 1000 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 + Ephedrine, Phenobarbital, Theophylline interactionErgotamine, Belladonna, PhenobarbitalBellamine, Bellaspas, Eperbel-S
How Ergotamine, Belladonna, Phenobarbital interacts with Double Strength L-Tryptophan 1000 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 + Ergotamine, Belladonna, Phenobarbital interactionEstazolamProsom
How Estazolam interacts with Double Strength L-Tryptophan 1000 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 + Estazolam interactionEszopicloneLunesta
How Eszopiclone interacts with Double Strength L-Tryptophan 1000 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 + Eszopiclone interactionEthosuximideZarontin
How Ethosuximide interacts with Double Strength L-Tryptophan 1000 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 + Ethosuximide interactionEthotoinPaganone
How Ethotoin interacts with Double Strength L-Tryptophan 1000 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 + Ethotoin interactionFelbamateFelbatol
How Felbamate interacts with Double Strength L-Tryptophan 1000 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 + Felbamate interactionFenfluamineFintepla
How Fenfluamine interacts with Double Strength L-Tryptophan 1000 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 + Fenfluamine interactionFentanylAbstral, Duragesic, Fentora, Lazanda, Sublimaze, Subsys
How Fentanyl interacts with Double Strength L-Tryptophan 1000 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 + Fentanyl interactionFentanyl Citrate, Oral Transmucosal Fentanyl CitrateActiq
How Fentanyl Citrate, Oral Transmucosal Fentanyl Citrate interacts with Double Strength L-Tryptophan 1000 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 + Fentanyl Citrate, Oral Transmucosal Fentanyl Citrate interactionFentanyl CitrateInnovar
How Fentanyl Citrate interacts with Double Strength L-Tryptophan 1000 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 + Fentanyl Citrate interactionFesoterodine FumarateToviaz
How Fesoterodine Fumarate interacts with Double Strength L-Tryptophan 1000 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 + Fesoterodine Fumarate interactionFlibanserinAddyi
How Flibanserin interacts with Double Strength L-Tryptophan 1000 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 + Flibanserin interactionFlupenthixolFluanxol
How Flupenthixol interacts with Double Strength L-Tryptophan 1000 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 + Flupenthixol interactionFlurazepamApo-Flurazepam, Bio-Flurazepam, Dalmane, Novo-Flurazepam, PMS-Flurazepam, Som Pam +1 more
How Flurazepam interacts with Double Strength L-Tryptophan 1000 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 + Flurazepam interactionFosphenytoinCerebyx
How Fosphenytoin interacts with Double Strength L-Tryptophan 1000 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 + Fosphenytoin interactionFosphenytoin SodiumSesquient
How Fosphenytoin Sodium interacts with Double Strength L-Tryptophan 1000 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 + Fosphenytoin Sodium interactionGabapentinGralise, Neurontin
How Gabapentin interacts with Double Strength L-Tryptophan 1000 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 + Gabapentin interactionGabapentin EnacarbilHorizant
How Gabapentin Enacarbil interacts with Double Strength L-Tryptophan 1000 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 + Gabapentin Enacarbil interactionGamma Hydroxybutyrate (prescription Drug)GHB
How Gamma Hydroxybutyrate (prescription Drug) interacts with Double Strength L-Tryptophan 1000 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 + Gamma Hydroxybutyrate (prescription Drug) interactionGanaxoloneZtalmy
How Ganaxolone interacts with Double Strength L-Tryptophan 1000 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 + Ganaxolone interactionGlutethimideDoriden
How Glutethimide interacts with Double Strength L-Tryptophan 1000 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 + Glutethimide interactionGuaifenesin, HydrocodoneEntuss, Pneumotussin
How Guaifenesin, Hydrocodone interacts with Double Strength L-Tryptophan 1000 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 + Guaifenesin, Hydrocodone interactionGuaifenesin, Hydrocodone BitartrateFlowtuss, Obredon
How Guaifenesin, Hydrocodone Bitartrate interacts with Double Strength L-Tryptophan 1000 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 + Guaifenesin, Hydrocodone Bitartrate interactionGuaifenesin, Hydrocodone Bitartrate, Pseudoephedrine HydrochlorideHycofenix
How Guaifenesin, Hydrocodone Bitartrate, Pseudoephedrine Hydrochloride interacts with Double Strength L-Tryptophan 1000 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 + Guaifenesin, Hydrocodone Bitartrate, Pseudoephedrine Hydrochloride interactionGuaifenesin, Hydrocodone, PseudoephedrineEntuss-D, Tussi-Organidin DM NR
How Guaifenesin, Hydrocodone, Pseudoephedrine interacts with Double Strength L-Tryptophan 1000 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 + Guaifenesin, Hydrocodone, Pseudoephedrine interactionHeroinHeroin
How Heroin interacts with Double Strength L-Tryptophan 1000 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 + Heroin interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Double Strength L-Tryptophan 1000 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 Double Strength L-Tryptophan 1000 mg, from the product label.
NOW
See all NOW products- Name
- NOW FOODS
- Street Address
- 395 S. Glen Ellyn Rd.
- City
- Bloomingdale
- State
- IL
- ZipCode
- 60108
- Web Address
- nowfoods.com
Double Strength L-Tryptophan 1000 mg by NOW: Common Questions
Does Double Strength L-Tryptophan 1000 mg by NOW 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 in the body?
Will this help with depression or anxiety?
What are the side effects?
Is it safe during pregnancy or breastfeeding?
Can I take this with my antidepressant?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Double Strength L-Tryptophan 1000 mg is safe with your meds?
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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.
The Full Monographs Behind Double Strength L-Tryptophan 1000 mg’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Sources & How We Checked
Double Strength L-Tryptophan 1000 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