L-Threonine 500 mg Ingredients & Drug Interactions
by Solgar
What is this page for?
First and foremost: checking L-Threonine 500 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-Threonine 500 mg is a dietary supplement by Solgar 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 500 mg by Solgar
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Threonine 500 mg by Solgar — 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 500 mg by Solgar
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-threonine, a 500 mg dose of an amino acid your body uses to build and repair tissues. The capsule also contains vegetable cellulose, stearic acid, and vegetable magnesium stearate — these are inactive ingredients that help form and stabilize the capsule.
Does it work?
Couldn't assess
L-threonine has been studied for several neurological conditions. For amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease), current evidence suggests it's possibly ineffective.
For multiple sclerosis, spasticity, and familial spastic paraparesis, there isn't enough reliable evidence in our data to say whether it works or doesn't.
How safe is it?
Well-documented data
Threonine from food is well tolerated, but supplement safety at higher doses like 500 mg hasn't been well studied. Common side effects reported in people taking threonine include headache and mild stomach upset — some have experienced diarrhea, gas, or constipation.
Supplement use in pregnancy and while breastfeeding hasn't been well studied; the safety data advises against taking it during these times unless your doctor has advised otherwise. Talk with your doctor or pharmacist before using this product if you're pregnant or nursing.
Meds to double-check
Major interaction found
Before taking this product, check with your doctor or pharmacist if you take any NMDA antagonist medications (such as memantine or ketamine). These drugs may become less effective when used with L-threonine.
No other medication interactions are documented in our data for this ingredient.
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 single-ingredient amino acid supplement that's most relevant if you're looking at it for neurological conditions — though the evidence for those uses is limited or unclear. The main caution is if you take NMDA antagonist medications; you'll need to check with your doctor or pharmacist first.
If you're pregnant, breastfeeding, or have any ongoing health condition or medications, run this by your own healthcare provider 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 Mar 24, 2020.
This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed
General information
Key facts about L-Threonine 500 mg, straight from the product label.
| Brand | Solgar |
|---|---|
| Barcode (UPC) | 033984027107 |
| Net contents | 100 Vegetable Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Mar 24, 2020 |
| DSLD ID | 214993 |
| Product type | Amino Acid/protein |
| Supplement form | Capsule |
| Dietary claims / uses | Nutrient, All Other |
| Intended target group(s) | Vegetarian, Adult (18 - 50 Years), Kosher, Gluten Free, Dairy Free, Sugar 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 500 mg by Solgar, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Threonine | 500 mg | -- |
Other ingredients: Vegetable Cellulose, Stearic Acid, Vegetable Magnesium Stearate
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.
Formulation
Solgar's L-Threonine Vegetable Capsules are free of corn, yeast, wheat, soy, gluten and dairy products and are formulated without the use of artificial preservatives, flavors or colors.
(Free form)
Suitable for vegetarians
Sugar, salt and starch free
L-Threonine is an essential amino acid. Long chains of molecularly bonded individual amino acids form protein. The body must first break these molecular (peptide) bonds for amino acid absorption to take place. Solgar's free form amino acids are already in their simplest form (no peptide bonds) and can be readily absorbed into the bloodstream.
Storage
To assure freshness and potency, store at room temperature 59 degrees-86 degrees F (15 degrees-30 degrees C). Store away from heat, light and moisture.
Formula
Solgar's KOF-K certification #K-1250
Precautions
Do not use if outer bottle seal is missing, torn or damaged in any way.
If you are pregnant, nursing, taking any medication or have a medical condition, please consult your healthcare practitioner before taking any dietary supplement.
Keep out of reach of children.
General Statements
Solgar since 1947
FDA Statement of Identity
Dietary Supplement
Seals/Symbols
K Parve (Kosher)
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement for adults, take one (1) vegetable capsule daily with juice or water, between meals, or as directed by a healthcare practitioner.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Threonine 500 mg by Solgar 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 500 mg by Solgar
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 Vegetarian Capsule(s) Dosage formCapsule 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 & interactionsOther (inactive) ingredients: Vegetable Cellulose, Stearic Acid, Vegetable Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.
L-Threonine 500 mg by Solgar Drug Interactions
HelloPharmacist Interaction Report
Solgar's L-Threonine 500 mg does interact with medications through its single active ingredient.
The most serious interaction is with NMDA antagonists (a class of drugs used for certain neurological conditions and sometimes pain or anesthesia). Threonine raises glycine levels in the brain, and glycine can enhance how NMDA receptors work — potentially reducing the effect of these medications.
Altogether, these interactions span 3 individual medications. If you take any NMDA antagonist, check the specific drug names with your doctor or pharmacist before starting this supplement.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Threonine 500 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-Threonine 500 mg interact with 3 drugs. Click any drug to see the details.
1 of the 1 ingredient in L-Threonine 500 mg interact with drugs. Each result below shows which ingredient is responsible. L-Threonine
MemantineEbixa
How Memantine interacts with L-Threonine 500 mg — 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 500 mg — 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 500 mg — 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 500 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-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 500 mg, from the product label.
Solgar
See all Solgar products- Name
- Solgar Vitamin and Herb
- City
- Leonia
- State
- N.J.
- ZipCode
- 07605
- Phone Number
- 1-877-765-4274
- Web Address
- www.solgar.com
L-Threonine 500 mg by Solgar: Common Questions
Does L-Threonine 500 mg by Solgar interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take L-threonine if I'm pregnant?
What side effects might I notice?
Does this really work for ALS or multiple sclerosis?
What exactly is L-threonine?
Can I breastfeed while taking this?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Threonine 500 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-Threonine 500 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-Threonine 500 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 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