L-Lysine 500 mg Ingredients & Drug Interactions
by Patient One 1 MediNutritionals
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 Patient One 1 MediNutritionals 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 Patient One 1 MediNutritionals
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine 500 mg by Patient One 1 MediNutritionals — 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
Ask the Pharmacist
A licensed pharmacist will answer your question by email — free, usually within 24 hours.
Got it — thank you!
A licensed pharmacist will answer within 24 hours. Keep an eye on your email (worth checking spam, just in case).
HelloPharmacist Scorecard of L-Lysine 500 mg by Patient One 1 MediNutritionals
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. Lysine is an amino acid—a building block your body uses to make protein and for other essential functions.
The capsule also contains three inactive ingredients (vegetable cellulose, microcrystalline cellulose, and calcium palmitate) that help form and hold the capsule together.
Does it work?
Moderate evidence
L-lysine is possibly effective for cold sores (herpes labialis). That means some evidence supports its use, but the research isn't as strong or complete as we'd like.
For child growth, pressure ulcers, and diabetic foot ulcers, the evidence we hold is insufficient to rate whether it works—we simply don't have enough reliable data yet.
How safe is it?
Well-documented data
Lysine is generally well tolerated at typical doses. The most common side effects reported when taking it by mouth are abdominal pain, diarrhea, and indigestion.
High amounts may cause stomach upset, and long-term safety hasn't been well studied. There is one case report of someone developing kidney inflammation and chronic kidney disease linked to oral lysine use, though this is rare.
Lysine from food is fine in pregnancy, but supplement safety during pregnancy and breastfeeding is not well studied—talk with your doctor or pharmacist before taking a lysine supplement if you're pregnant or nursing.
Meds to double-check
Minor interactions only
If you take a 5-HT4 agonist medication, ask your doctor or pharmacist whether lysine is right for you—it may reduce how well the drug works. For all other medication questions, use the search tool on this page or talk it over with your own pharmacist.
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 if the evidence pans out for you. It's generally well tolerated, though high doses can cause stomach upset.
If you take a 5-HT4 agonist medication, check with your doctor or pharmacist first—lysine may weaken its effect. Pregnant or breastfeeding?
Chat with your healthcare provider before starting 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 Oct 24, 2022.
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 | Patient One 1 MediNutritionals |
|---|---|
| Barcode (UPC) | 859782006652 |
| Net contents | 120 Vegetable Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Oct 24, 2022 |
| DSLD ID | 276260 |
| Product type | Amino Acid/protein |
| Supplement form | Capsule |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Vegetarian, 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-Lysine 500 mg by Patient One 1 MediNutritionals, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Lysine Hydrochloride | 500 mg | -- |
Other ingredients: Vegetable Cellulose, Microcrystalline Cellulose, Calcium Palmitate
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
Vegetarian
Gluten free Non-GMO
Free of: milk, egg, fish, peanuts, crustacean shellfish, soy, tree nuts, wheat, yeast and gluten. Free of ingredients derived from GMOs.
Suggested/Recommended/Usage/Directions
Suggested use: Take 1 capsule, 2 to 3 times daily as a dietary supplement, preferably between meals, or as directed by your health practitioner.
Storage
Store in a cool, dry place.
Precautions
Caution: If you are pregnant, nursing, or taking any medications, consult your health practitioner before use.
Discontinue use and consult your health practitioner if any adverse reactions occur.
Keep out of reach of children.
Use only if safety seal is intact.
General Statements
BPA free
Exclusive professional formulas
FDA Statement of Identity
Dietary Supplement
FDA Disclaimer Statement
These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine 500 mg by Patient One 1 MediNutritionals 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 Patient One 1 MediNutritionals
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 container120 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: Vegetable Cellulose, Microcrystalline Cellulose, Calcium Palmitate. These complete the product’s ingredient list but are not active constituents.
L-Lysine 500 mg by Patient One 1 MediNutritionals Drug Interactions
HelloPharmacist Interaction Report
L-Lysine 500 mg by Patient One 1 MediNutritionals may interact with one class of medications through its lysine content.
The interaction is minor: lysine may reduce the effects of 5-HT4 agonists, a group of drugs used to treat certain digestive and other conditions. Animal research suggests lysine acts as a partial blocker of the serotonin receptor 4 that these medications target, which could weaken how well they work.
Read the full breakdown — every affected drug type, severity by severity
Although this interaction is documented as minor, it's worth checking if you take any 5-HT4 agonist medication. If you do, run it through the search tool on this page or ask your doctor or pharmacist whether taking lysine alongside it makes sense for you.
Altogether, these interactions span 1 individual medication.
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.
Patient One 1 MediNutritionals
See all Patient One 1 MediNutritionals products- Name
- MediNutritionals Research LLC
- City
- Hauppage
- State
- NY
- ZipCode
- 11788
- Phone Number
- (631) 390-9669
- Web Address
- patientoneformulas.com
L-Lysine 500 mg by Patient One 1 MediNutritionals: Common Questions
Does L-Lysine 500 mg by Patient One 1 MediNutritionals interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Does lysine really help with cold sores?
What are the side effects?
Can I take this while pregnant or breastfeeding?
Is lysine the same as L-lysine?
What are the inactive ingredients?
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