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Dietary supplement

L-Lysine Ingredients & Drug Interactions

by XYMOGEN

Capsule Category: Amino Acid/protein
Most serious interaction: Minor
The interaction bottom line Most serious interaction: Minor

L-Lysine is a dietary supplement by XYMOGEN 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.

HelloPharmacist Scorecard of L-Lysine by XYMOGEN

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.

From our pharmacy team — supplement deep dive

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: L-Lysine, an amino acid your body uses to build proteins and support various functions. The capsule also contains inactive ingredients—HPMC, stearic acid, microcrystalline cellulose, magnesium stearate, and silica—which are fillers and binders that help form and stabilize the capsule.

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

We hold no graded evidence for this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: essential amino acid support.
  • We looked for evidence on: protein synthesis, collagen formation, nutrient absorption.
  • Our graded evidence for these ingredients doesn't cover that particular purpose.

L-Lysine is possibly effective for cold sores (herpes labialis) according to the evidence we have on file. For other uses listed—child growth, pressure ulcers, and diabetic foot ulcers—the evidence is insufficient to rate whether it works.

The evidence, ingredient by ingredient Lysine

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

L-Lysine is generally well tolerated at typical doses. At high amounts, it may cause stomach upset, abdominal pain, diarrhea, or indigestion; long-term safety at higher doses isn't well studied.

There's one rare case report of it being linked to kidney inflammation progressing to chronic kidney disease, though this is not established as a common risk. Supplement safety in pregnancy and while breastfeeding hasn't been well studied—lysine from food is fine, but if you're pregnant or nursing, check with your doctor before taking this supplement to decide what's right for you.

Side effects, ingredient by ingredient Lysine

Meds to double-check

Minor interactions only
Known Interaction Concern · database check
Minor only

Only Minor-severity interactions are documented for these ingredients.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Lysine.
  • The most serious interaction on file is rated Minor.
  • For scale: 1 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take a 5-HT4 agonist (a medication that helps move food through your stomach or bowels), L-Lysine may reduce how well it works. Check with your doctor or pharmacist before combining them.

Altogether, these interactions span 1 individual medication.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Only minor medication interactions are documented, and safety information is well characterized.

L-Lysine may help with cold sores if you're looking for evidence-based support. It's generally well tolerated, but high doses and long-term use aren't well studied.

If you're pregnant, breastfeeding, or take any medications—especially those for GI motility—talk it over with your doctor or pharmacist before starting.

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 23, 2012.

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

At a glance

General information

Key facts about L-Lysine, straight from the product label.

Brand XYMOGEN
Net contents 90 Vegetable Capsule(s)
Market status On market
Date entered into DSLD Mar 23, 2012
DSLD ID 6136
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Gluten Free
From the label
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 by XYMOGEN, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
45
IngredientAmount% DV
L-Lysine1000 mg--

Other ingredients: HPMC, Stearic Acid, Microcrystalline Cellulose, Magnesium Stearate, Silica

Tap any ingredient to jump to its full detail below.

Label statements
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

Suggested/Recommended/Usage/Directions

DIRECTIONS: Preferably on an empty stomach, take one to two capsules three times a day, or as directed by your healthcare practitioner.

Precautions

Keep out of reach of children.

Avoid if allergic to any ingredient.

CAUTIONS: Consult your healthcare practitioner before use.

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.

Storage

STORAGE: Keep tightly closed in a cool, dry place.

General Statements

An Essential Amino Acid

This package is completely recyclable (recycle)

Exclusive Professional Formulas • Pharmaceutical Grade • Professional Use Only

General

TC# E0670901 REV. 060711

Brand IP Statement(s)

XYMOGEN 2011

All XYMOGEN(R) Formulas Meet or Exceed cGMP Quality Standards.

L-Lysine is an amino acid essential in human physiology. Lysine is vital for normal growth and for the manufacture of collagen, a substance important for healthy skin, bones, tendons, and cartilage. Supplemental lysine may be appropriate for individuals on a high-arginine diet.*

Formulation

DOES NOT CONTAIN: Wheat, gluten, corn protein, yeast, soy, animal or dairy products, artificial colors, sweeteners, or preservatives.

Seals/Symbols

VEGETABLE CAPSULES

See for yourself

L-Lysine by XYMOGEN label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

What’s inside

The Ingredients in L-Lysine by XYMOGEN

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 container45 Amounts shown are per serving.

L-Lysine

Interacts with
1 drug
1000 mg per serving Form: L-Lysine Hydrochloride

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 & interactions

Other (inactive) ingredients: HPMC, Stearic Acid, Microcrystalline Cellulose, Magnesium Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Lysine by XYMOGEN Drug Interactions

Want to check YOUR meds against L-Lysine?

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 checker
1Drugs
1 Minor

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in L-Lysine 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-Lysine1 drug type · 1 drug

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.

Likelihood Unlikely Evidence D
The maker

Brand information

Manufacturer and brand details for L-Lysine, from the product label.

XYMOGEN

See all XYMOGEN products
Name
XYMOGEN Exclusive Professional Formulas
Street Address
725 S. Kirkman Rd.
City
Orlando
State
FL
ZipCode
32811
Phone Number
800-647-6100
Web Address
www.xymogen.com
Pharmacist Counseling Corner

L-Lysine by XYMOGEN: Common Questions

Does L-Lysine by XYMOGEN interact with any medications?
Yes. Based on its ingredients, L-Lysine has a known interaction with 1 medication. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
L-Lysine contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does L-Lysine actually work for cold sores?
The evidence suggests it's possibly effective—meaning there's some support for it, but it's not definitive. Talk to your doctor or pharmacist about whether it's a good choice for you.
Can I take this if I'm pregnant?
Safety during pregnancy hasn't been well studied, so we can't say for certain either way. Check with your doctor first—they can help you decide what's safest for you and your baby.
What side effects might I notice?
At typical doses, L-Lysine is generally well tolerated. At higher amounts, some people report stomach pain, diarrhea, or indigestion. If you're taking large doses long-term, that safety data is limited.
Can I breastfeed while taking this?
There isn't enough reliable data to know whether it's safe while breastfeeding, so caution is advised. Talk with your doctor or pharmacist to figure out what's best for you and your baby.
Is there anything else in this capsule besides the lysine?
Yes—the capsule also contains inactive ingredients like cellulose, stearic acid, and silica, which help stabilize and form the capsule. They're not active in the way lysine is, but they make the supplement shelf-stable.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if L-Lysine is safe with your meds?

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Ask a pharmacist

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.

L-Lysine label
Sources

Sources & How We Checked

L-Lysine'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.

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
  1. 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
  2. McCune MA, Perry HO, Muller SA, O'Fallon WM. Treatment of recurrent herpes simplex infections with L-lysine monohydrochloride. Cutis 1984;34:366-73.
  3. DiGiovanna JJ, Blank H. Failure of lysine in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Arch Dermatol 1984;120:48-51. DOI
  4. 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.
  5. 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
  6. 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
  7. 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.

See these in context on the Lysine monograph →

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

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