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 Puritan's Pride 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. 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 Puritan's Pride
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine 500 mg by Puritan's Pride — 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 Puritan's Pride
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, an amino acid. L-lysine is a building block your body uses for protein synthesis and various metabolic functions.
The supplement is made in a vegetable cellulose capsule with minimal inactive ingredients.
Does it work?
Moderate evidence
L-lysine is possibly effective for cold sores (herpes labialis) — the evidence supports its use for this purpose. For other uses listed — child growth, pressure ulcers, and diabetic foot ulcers — there isn't enough reliable evidence in our data to establish whether it works.
How safe is it?
Well-documented data
L-lysine is generally well tolerated at typical doses. The most common side effects from oral use are abdominal pain, diarrhea, and indigestion; high amounts may increase the risk of stomach upset.
Long-term safety hasn't been well studied. For pregnancy and breastfeeding, supplement safety hasn't been well studied, so talk with your doctor before taking it while pregnant or nursing.
Meds to double-check
Minor interactions only
If you take a 5-HT4 agonist — a medication that works on serotonin receptors in the digestive tract — let your doctor or pharmacist know before starting L-lysine, as it may reduce how well that drug works.
The bottom line
Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. Only minor medication interactions are documented, and safety information is well characterized.
L-Lysine is a straightforward single-ingredient supplement most commonly used for cold sores, where it has decent evidence behind it. If you take medications for gut motility or serotonin-related conditions, check with your doctor or pharmacist first.
Otherwise, it's worth running your exact medications through the interaction checker 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 Jul 25, 2017.
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 | Puritan's Pride |
|---|---|
| Barcode (UPC) | 074312130601 |
| Net contents | 100 Caplet(s) |
| Market status | On market |
| Date entered into DSLD | Jul 25, 2017 |
| DSLD ID | 76476 |
| Product type | Amino Acid/protein |
| Supplement form | Other (e.g. Tea Bag) |
| Dietary claims / uses | All Other |
| Intended target group(s) | Vegetarian, Adult (18 - 50 Years), 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-Lysine 500 mg by Puritan's Pride, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Lysine | 500 mg | -- |
Other ingredients: Vegetable Cellulose, Contains <2% of
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)
Puritan’s Pride supplements are produced from the finest raw materials under stringent quality control standards.
2017 Puritan’s Pride, Inc.
General Statements
State-of-the-art manufacturing and packaging facilities ensure you the highest quality nutritional supplements money can buy. When it comes to your health...choose the best.
To reorder item # 3060 www.puritan.com 1-800-645-1030
Free form
Precautions
Warning: If you are pregnant, nursing, taking any medications or have any medical condition, consult your doctor before use.
Discontinue use and consult your doctor if any adverse reactions occur.
Keep out of reach of children.
Do not use if seal under cap is broken or missing.
Storage
Store at room temperature.
General
Item # 3060 B52576 15F 14-20137PPS
Seals/Symbols
QA Quality Assured
FDA Statement of Identity
Vegetarian Amino Acid Supplement
Formulation
Vegetarian Amino Acid Supplement
No artificial color, flavor or sweetener, no preservatives, no sugar, no starch, no milk, no lactose, no soy, no gluten, no wheat, no yeast, no fish. Sodium free.
Suggested/Recommended/Usage/Directions
Directions: For adults, take one (1) caplet two times daily, preferably on an empty stomach.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine 500 mg by Puritan's Pride 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 Puritan's Pride
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 Caplet(s) Dosage formOther (e.g. Tea Bag) Amounts shown are per serving.
L-Lysine
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 monograph & interactionsOther (inactive) ingredients: Vegetable Cellulose, Contains <2% of. These complete the product’s ingredient list but are not active constituents.
L-Lysine 500 mg by Puritan's Pride Drug Interactions
HelloPharmacist Interaction Report
L-Lysine 500 mg from Puritan's Pride has one documented interaction.
Through its L-lysine content, it may reduce the effects of 5-HT4 agonists (a class of drugs that work on serotonin receptors in the gut). Animal research suggests lysine acts as a partial antagonist to these drugs, which could blunt their intended effect.
Altogether, these interactions span 1 individual medication. Check your exact medications with the tool on this page before starting.
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
TegaserodZelnorm
How Tegaserod interacts with L-Lysine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
L-lysine5-ht4 Agonists Minor
Interaction Summary
Theoretically, lysine may reduce the effects of 5-HT4 agonists.
Read the full L-lysine + 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
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.
Puritan's Pride
See all Puritan's Pride products- Name
- Puritan's Pride, Inc.
- City
- Ronkonkoma
- State
- NY
- ZipCode
- 11779
- Phone Number
- 1-800-645-1030
- Web Address
- www.puritan.com
L-Lysine 500 mg by Puritan's Pride: Common Questions
Does L-Lysine 500 mg by Puritan's Pride interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Does L-lysine actually work for cold sores?
What side effects should I expect?
Is it safe to take L-lysine while pregnant?
Can I take this while breastfeeding?
What is L-lysine and why do I need it?
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