L-Threonine Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Threonine 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-Threonine is a dietary supplement by BulkSupplements.com with 1 active ingredient. Its ingredients are commonly taken for general amino acid/protein support, muscle and tissue health, immune support.Based on those ingredients, 3 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are L-Threonine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against L-Threonine by BulkSupplements.com
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Threonine 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
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HelloPharmacist Scorecard of L-Threonine 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 is pure L-threonine, a single amino acid with no added inactive ingredients. L-threonine is one of the essential amino acids your body needs but cannot make on its own — you normally get it from protein-containing foods like poultry, cheese, and eggs.
This powder form lets you add extra threonine to your daily intake beyond what you eat.
Does it work?
Couldn't assess
The evidence for L-threonine is mixed. For ALS (Lou Gehrig's disease), the research suggests it is likely not helpful.
For multiple sclerosis, familial spastic paraparesis, and spasticity, we don't have enough reliable evidence yet to know whether it works. If you're considering this supplement for one of these conditions, talk it over with your doctor so you can weigh what we do know.
How safe is it?
Well-documented data
Threonine from food is safe and you eat it all the time. Supplements at higher doses haven't been well studied, so caution is warranted — we simply don't have solid data on long-term safety at supplement levels.
The most common side effects reported are headache and mild stomach upset, including diarrhea, constipation, or gas. Because supplement use in pregnancy and breastfeeding hasn't been well studied, the safety data advises against it unless a clinician has advised you otherwise.
Talk with your doctor or pharmacist before using this if you're pregnant, nursing, or planning to become pregnant.
Meds to double-check
Major interaction found
Check before taking this if you use any NMDA antagonist medication — including ketamine, memantine, or dextromethorphan (found in many over-the-counter cough medicines). These interactions are documented as Major, meaning they could meaningfully reduce how your medication works.
Your doctor or pharmacist can advise whether it's safe to use L-threonine alongside your specific drugs.
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-Threonine is a basic amino acid supplement with limited evidence for the conditions it's marketed for. The main thing to watch is that it may weaken NMDA antagonist medications — so if you take any drug in that class, clear it with your doctor or pharmacist first.
Because high-dose supplement safety isn't well established, and pregnancy and breastfeeding safety data is thin, check with your healthcare provider before starting, especially if you're in those situations.
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 May 23, 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 L-Threonine, straight from the product label.
| Brand | BulkSupplements.com |
|---|---|
| Barcode (UPC) | X000IOD277 |
| Net contents | 100 Gram(s); 3.5 Ounce(s) |
| Market status | On market |
| Date entered into DSLD | May 23, 2024 |
| DSLD ID | 312280 |
| Product type | Amino Acid/protein |
| Supplement form | Powder |
| 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-Threonine by BulkSupplements.com, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Threonine | 500 mg | -- |
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.
Brand IP Statement(s)
BulkSupplements.com Clean & Pure Bulk Supplements
Formulation
Free of: Added sugar, soy, dairy, yeast, gluten, additives
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement, take 500 mg (about 1/5 tsp) once daily, or as directed by a physician.
General Statements
Use an accurate milligram scale.
New
Storage
Contents are sold by weight, not volume. Settling may occur. Store in a dry, cool place
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.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Threonine 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-Threonine by BulkSupplements.com
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size500 mg Dosage formPowder Servings per container200 Amounts shown are per serving.
L-Threonine
Interacts with3 drugs
Threonine is an essential amino acid your body needs but cannot make, so you must get it from food or supplements. Most people get plenty from a norma...
L-Threonine monograph & interactionsL-Threonine by BulkSupplements.com Drug Interactions
HelloPharmacist Interaction Report
L-Threonine by BulkSupplements.com interacts with NMDA antagonists (a class of medications that block a specific type of brain receptor).
The concern is Major: threonine raises levels of glycine in your central nervous system, and glycine enhances how NMDA receptors work — so threonine may reduce the effectiveness of drugs in this class. Altogether, these interactions span 3 individual medications.
Read the full breakdown — every affected drug type, severity by severity
If you take any NMDA antagonist — such as ketamine, memantine, or dextromethorphan (the cough suppressant in some cold medicines) — check with your doctor or pharmacist before starting this supplement. They can tell you whether the interaction matters for your specific situation and whether you need to adjust your dosing or timing.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Threonine?
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-Threonine interact with 3 drugs. Click any drug to see the details.
1 of the 1 ingredient in L-Threonine interact with drugs. Each result below shows which ingredient is responsible. L-Threonine
MemantineEbixa
How Memantine interacts with L-Threonine — through 1 ingredient. Tap an ingredient for the detail:
L-threonineNmda Antagonists Major
Interaction Summary
Theoretically, threonine might decrease the effects of NMDA antagonists.
Read the full L-threonine + Memantine interactionMemantine HydrochlorideNamenda
How Memantine Hydrochloride interacts with L-Threonine — through 1 ingredient. Tap an ingredient for the detail:
L-threonineNmda Antagonists Major
Interaction Summary
Theoretically, threonine might decrease the effects of NMDA antagonists.
Read the full L-threonine + Memantine Hydrochloride interactionMemantine, DonepezilNamzaric
How Memantine, Donepezil interacts with L-Threonine — through 1 ingredient. Tap an ingredient for the detail:
L-threonineNmda Antagonists Major
Interaction Summary
Theoretically, threonine might decrease the effects of NMDA antagonists.
Read the full L-threonine + Memantine, Donepezil interactionEach ingredient & the kinds of drugs it affects
For each ingredient in L-Threonine 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-Threonine
Nmda Antagonists
Theoretically, threonine might decrease the effects of NMDA antagonists.
Threonine increases central nervous system (CNS) glycine levels. Glycine seems to bind a site on NMDA receptors and enhance the activity of the receptors.
Brand information
Manufacturer and brand details for L-Threonine, 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-Threonine by BulkSupplements.com: Common Questions
Does L-Threonine 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-threonine, and why would I take it?
Can I take this if I'm pregnant or breastfeeding?
What side effects have been reported?
Does it actually work for ALS or multiple sclerosis?
I take ketamine (or memantine, or cough syrup with dextromethorphan). Can I use this?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Threonine 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-Threonine’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Sources & How We Checked
L-Threonine'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 4 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.
Threonine 4 references
- Tandan R, Bromberg MB, Forshew D, et al. A controlled trial of amino acid therapy in amyotrophic lateral sclerosis: I. Clinical, functional, and maximum isometric torque data. Neurology 1996;47:1220-6. PubMed
- Lee A, Patterson V. A double blind study of L-threonine in patients with spinal spasticity. Acta Neurol Scand 1993;88:334-8. PubMed
- Blin O, Pouget J, Aubrespy G, et al. A double-blind placebo controlled trial of L-threonine in amyotrophic lateral sclerosis. J Neurol 1992;239:79-81.
- Roufs JB. L-threonine as a symptomatic treatment for amyotrophic lateral sclerosis (ALS). Med Hypotheses 1991;34:20-3. 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