L-Lysine 500 mg Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Lysine 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-Lysine 500 mg is a dietary supplement by Ecological Formulas with 1 active ingredient. Its ingredients are commonly taken for cold sores (herpes labialis), genital herpes outbreaks, supporting protein and collagen formation.Based on those ingredients, 1 medication has a known interaction with it, the most serious rated minor. The ingredients most likely to interact are L-Lysine Hydrochloride. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against L-Lysine 500 mg by Ecological Formulas
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine 500 mg by Ecological Formulas — 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-Lysine 500 mg by Ecological Formulas
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-lysine hydrochloride at 500 mg per capsule. L-lysine is an amino acid — one of the building blocks your body uses to make protein.
The capsule itself also holds gelatin, silicon dioxide, and magnesium stearate as inactive ingredients.
Does it work?
Moderate evidence
L-lysine is possibly effective for cold sores (herpes labialis), which is where most of the evidence sits. For other uses listed — supporting child growth, preventing pressure ulcers, and healing diabetic foot ulcers — we don't have enough reliable evidence to know whether it works.
How safe is it?
Well-documented data
L-lysine from food is fine, but when you take it as a supplement, the long-term safety picture isn't well studied. At typical doses it's generally well tolerated, though some people report stomach upset, diarrhea, or belly pain, especially at higher amounts.
There's also one case report of kidney trouble linked to high-dose lysine, though this is rare. Because supplement safety in pregnancy isn't well studied, talk with your doctor before starting if you're pregnant.
The same goes for breastfeeding — we don't have enough information to say it's safe, so check with your doctor or pharmacist first.
Meds to double-check
Minor interactions only
If you take a 5-HT4 agonist (a medication that helps certain digestive problems), check with your doctor or pharmacist before adding L-lysine — it may reduce how well your drug works. No other medication interactions are documented for the ingredients we could check.
The bottom line
Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Only minor medication interactions are documented, and safety information is well characterized.
L-lysine may help with cold sores, though the evidence is modest. If you're taking a 5-HT4 agonist for digestive issues, mention this supplement to your doctor or pharmacist before you start — they'll want to keep an eye on how well your medication works.
If you're pregnant or breastfeeding, talk it over with your healthcare provider before taking it.
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 Dec 14, 2023.
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-Lysine 500 mg, straight from the product label.
| Brand | Ecological Formulas |
|---|---|
| Barcode (UPC) | 696859132254 |
| Net contents | 250 Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Dec 14, 2023 |
| DSLD ID | 299777 |
| Product type | Amino Acid/protein |
| Supplement form | Capsule |
| Dietary claims / uses | All Other |
| Intended target group(s) | Adult (18 - 50 Years), Gluten 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-Lysine 500 mg by Ecological Formulas, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Lysine Hydrochloride | 500 mg | -- |
Other ingredients: Gelatin, Silicon Dioxide, 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.
FDA Statement of Identity
Dietary Supplement
Formula
Only the purest form of the amino acid, L-Lysine is present in this formula.
Crystalline Amino Acid
Formulation
Free of soy, yeast, wheat, sugar, starch, coloring agents, and artificial flavoring.
Gluten free, Casein free
Suggested/Recommended/Usage/Directions
Directions Take one capsule daily between meals, or as directed by a physician. L-Lysine may be taken in conjunction with vitamins and minerals. Do not refrigerate. Do not take with dairy products.
Precautions
Do not take with dairy products.
Storage
Do not refrigerate.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine 500 mg by Ecological Formulas 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-Lysine 500 mg by Ecological Formulas
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 container250 Amounts shown are per serving.
L-Lysine Hydrochloride
Interacts with1 drug
Lysine is an essential amino acid your body cannot make on its own, so it must come from food or supplements. People most often take extra lysine to t...
L-Lysine Hydrochloride monograph & interactionsOther (inactive) ingredients: Gelatin, Silicon Dioxide, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.
L-Lysine 500 mg by Ecological Formulas Drug Interactions
HelloPharmacist Interaction Report
L-Lysine 500 mg by Ecological Formulas has one documented interaction we need to flag.
Through its L-lysine content, this supplement may reduce the effects of 5-HT4 agonists — a group of medications used to help with certain digestive issues. Animal research suggests lysine can block some of the activity of these drugs, though the real-world significance in people isn't yet clear.
Read the full breakdown — every affected drug type, severity by severity
Additionally, no other medication interactions are documented in our data for this product. Altogether, these interactions span 1 individual medication.
Before you start L-lysine, check with your doctor or pharmacist if you're taking a 5-HT4 agonist — they'll want to know so they can monitor how well it's working for you.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Lysine 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-Lysine 500 mg interact with 1 drug. Click any drug to see the details.
1 of the 1 ingredient in L-Lysine 500 mg interact with drugs. Each result below shows which ingredient is responsible. L-Lysine Hydrochloride
TegaserodZelnorm
How Tegaserod interacts with L-Lysine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
L-lysine Hydrochloride5-ht4 Agonists Minor
Interaction Summary
Theoretically, lysine may reduce the effects of 5-HT4 agonists.
Read the full L-lysine Hydrochloride + Tegaserod interactionEach ingredient & the kinds of drugs it affects
For each ingredient in L-Lysine 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-Lysine Hydrochloride
5-Ht4 Agonists
Theoretically, lysine may reduce the effects of 5-HT4 agonists.
Animal research suggests that L-lysine is a partial serotonin receptor 4 (5-HT4) antagonist and inhibits diarrhea induced by the 5-HT4 agonist, 5-hydroxytryptophane.
Brand information
Manufacturer and brand details for L-Lysine 500 mg, from the product label.
Ecological Formulas
See all Ecological Formulas products- Name
- Ecological Formulas
- Street Address
- 1061-B Shary Circle
- City
- Concord
- State
- CA
- ZipCode
- 94518
L-Lysine 500 mg by Ecological Formulas: Common Questions
Does L-Lysine 500 mg by Ecological Formulas interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Will L-lysine help my cold sores?
What side effects should I watch for?
Is it safe to take while pregnant?
Can I take it while breastfeeding?
What is L-lysine, and why is it in supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Lysine 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-Lysine 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-Lysine 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 7 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.
Lysine 7 references
- Thein DJ, Hurt WC. Lysine as a prophylactic agent in the treatment of recurrent herpes simplex labialis. Oral Surg Oral Med Oral Pathol 1984;58:659-66. PubMed
- McCune MA, Perry HO, Muller SA, O'Fallon WM. Treatment of recurrent herpes simplex infections with L-lysine monohydrochloride. Cutis 1984;34:366-73.
- DiGiovanna JJ, Blank H. Failure of lysine in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Arch Dermatol 1984;120:48-51. DOI
- Milman N, Scheibel J, Jessen O. Lysine prophylaxis in recurrent herpes simplex labialis: a double-blind, controlled crossover study. Acta Derm Venereol 1980;60:85-7.
- Griffith RS, Walsh DE, Myrmel KH, et al. Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Dermatologica 1987;175:183-90. DOI
- Lo JC, Chertow GM, Rennke H, Seifter JL. Fanconi's syndrome and tubulointerstitial nephritis in association with L-lysine ingestion. Am J Kidney Dis 1996;28:614-7. PubMed
- Smriga M, Torii K. L-Lysine acts like a partial serotonin receptor 4 antagonist and inhibits serotonin-mediated intestinal pathologies and anxiety in rats. Proc Natl Acad Sci U S A. 2003 Dec 23;100(26):15370-5.
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