L-Lysine 620 mg Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Lysine 620 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 620 mg is a dietary supplement by Life Extension 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 620 mg by Life Extension
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine 620 mg by Life Extension — 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 620 mg by Life Extension
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: 620 mg of L-lysine, an amino acid (a building block your body uses to make protein). The capsule also contains inactive fillers: vegetable cellulose, vegetable stearate, and L-leucine.
Does it work?
Moderate evidence
L-Lysine is possibly effective for cold sores (herpes labialis) — the evidence suggests it may help, though more research would strengthen that claim. For child growth, pressure ulcers, and diabetic foot ulcers, there isn't enough reliable evidence yet to say whether it works.
How safe is it?
Well-documented data
L-Lysine from food is safe, and the supplement is generally well tolerated at typical doses. High amounts may cause stomach upset, diarrhea, abdominal pain, or indigestion.
Long-term safety at high doses hasn't been well studied. Supplement use in pregnancy is not well studied — the facts advise checking with your doctor first.
There's not enough reliable data on breastfeeding, so caution is advised if you're nursing — talk it over with your doctor or pharmacist to weigh the benefits and unknowns.
Meds to double-check
Minor interactions only
If you take a 5-HT4 agonist, check with your pharmacist or doctor before starting this product — lysine may weaken its effect.
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 be worth trying if you get cold sores and want to explore natural options. If you take a 5-HT4 agonist for a GI condition, check with your doctor or pharmacist before adding this supplement.
Keep doses moderate to sidestep stomach upset, and if you're pregnant or breastfeeding, get personalized advice from your healthcare provider first.
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 Aug 23, 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-Lysine 620 mg, straight from the product label.
| Brand | Life Extension |
|---|---|
| Barcode (UPC) | 737870167815 |
| Net contents | 100 Vegetarian Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Aug 23, 2020 |
| DSLD ID | 232176 |
| Product type | Amino Acid/protein |
| Supplement form | Capsule |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years) |
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 620 mg by Life Extension, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Lysine | 620 mg | -- |
Other ingredients: Vegetable Cellulose, Vegetable Stearate, L-Leucine
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.
Suggested/Recommended/Usage/Directions
Read the entire label and follow the directions carefully prior to use. Directions: Take one (1) capsule one to three times daily on an empty stomach, or as recommended by a healthcare practitioner.
Precautions
Warnings: Keep out of reach of children.
Do not exceed recommended dose. Do not purchase if outer seal is broken or damaged.
When using nutritional supplements, please consult with your physician if you are undergoing treatment for a medical condition or if you are pregnant or lactating.
To report a serious adverse event or obtain product information, contact 1-866-280-2852.
FDA Disclaimer Statement
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Seals/Symbols
Non GMO LE Certified
Formulation
Non GMO LE Certified
Formula
Essential amino acid support
FDA Statement of Identity
Dietary Supplement
Storage
Store tightly closed in a cool, dry place.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine 620 mg by Life Extension 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 620 mg by Life Extension
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-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, Vegetable Stearate, L-Leucine. These complete the product’s ingredient list but are not active constituents.
L-Lysine 620 mg by Life Extension Drug Interactions
HelloPharmacist Interaction Report
Life Extension L-Lysine 620 mg may interact with 5-HT4 agonists (a class of drugs used for certain GI conditions).
Animal research suggests lysine can partially block these drugs' effects, which could reduce how well they work — a Minor interaction. Altogether, these interactions span 1 individual medication.
Because the evidence comes from animal studies rather than human trials, the real-world impact isn't certain, but it's worth flagging. If you take a 5-HT4 agonist, run it through the checker on this page or ask your pharmacist before starting lysine.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Lysine 620 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 620 mg interact with 1 drug. Click any drug to see the details.
1 of the 1 ingredient in L-Lysine 620 mg interact with drugs. Each result below shows which ingredient is responsible. L-Lysine
TegaserodZelnorm
How Tegaserod interacts with L-Lysine 620 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 620 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 620 mg, from the product label.
Life Extension
See all Life Extension products- Name
- Quality Supplements and Vitamins, Inc.
- City
- Ft. Lauderdale
- State
- FL
- ZipCode
- 33309
- Phone Number
- 1-866-280-2852
- Web Address
- LifeExtension.com
L-Lysine 620 mg by Life Extension: Common Questions
Does L-Lysine 620 mg by Life Extension interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Will L-Lysine help prevent or treat my cold sores?
What side effects should I watch for?
Is it safe to take L-Lysine while pregnant?
Can I take L-Lysine while breastfeeding?
What is L-Lysine and why would I take it?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Lysine 620 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 620 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 620 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