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Dietary supplement

L-Lysine 1000 mg Ingredients & Drug Interactions

by GNC

Other (e.g. Tea Bag) Category: Amino Acid/protein
Most serious interaction: Minor
The interaction bottom line Most serious interaction: Minor

L-Lysine 1000 mg is a dietary supplement by GNC 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 1000 mg by GNC

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 at 1000 mg per dose. The inactive ingredients are povidone, stearic acid, silicon dioxide, and magnesium stearate—all fillers and binders that help hold the tablet together.

Does it work?

Moderate evidence
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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: supports tissue repair and collagen formation.
  • We looked for evidence on: Herpes labialis (cold sores), Pressure ulcers, Wound healing, Tissue integrity.
  • The strongest evidence on file: Lysine is rated "Possibly Effective" for Herpes labialis (cold sores) (Natural Medicines).
  • Also on file: Lysine is rated "Insufficient Reliable Evidence To Rate" for Pressure ulcers.

L-lysine is possibly effective for herpes labialis, commonly known as cold sores. The evidence for child growth, pressure ulcers, and diabetic foot ulcers is insufficient—we don't have enough reliable data to rate how well it works for those uses.

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. The most common side effects are abdominal pain, diarrhea, and indigestion.

High amounts may cause stomach upset, and long-term safety of supplements hasn't been thoroughly studied. There's also one case report of kidney inflammation linked to oral lysine, though this is rare.

Pregnancy and breastfeeding safety data for supplements is limited. Lysine from food is fine, but if you're pregnant or breastfeeding and want to take a supplement, talk with your doctor first—there isn't enough reliable information to know either way.

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 drug used for certain digestive issues—check with your doctor or pharmacist before starting L-lysine. Animal research suggests lysine may reduce how well these medications work, though the interaction is rated minor.

Check your own medication Run your meds through the checker above

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 you're looking for a possibly effective option. It's generally well tolerated, but high doses can upset your stomach and long-term safety isn't fully established.

If you take a 5-HT4 agonist or have any kidney concerns, check with your doctor or pharmacist before starting. Either way, it's worth running your full medication list past them to be sure.

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 Jan 22, 2021.

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 1000 mg, straight from the product label.

Brand GNC
Barcode (UPC) 048107211318
Net contents 90 Vegetarian Caplet(s)
Market status On market
Date entered into DSLD Jan 22, 2021
DSLD ID 242992
Product type Amino Acid/protein
Supplement form Other (e.g. Tea Bag)
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Kosher, Gluten Free, Dairy Free, Sugar 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 1000 mg by GNC, 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 Caplet(s)
Maximum serving Sizes:
1 Caplet(s)
Servings per container
90
UPC/BARCODE
048107211318
IngredientAmount% DV
L-Lysine1000 mg--

Other ingredients: Povidone, Stearic Acid, Silicon Dioxide, Magnesium Stearate

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.
Precautions

Keep out of reach of children.

Storage

Store in a cool, dry place.

Formulation

Supports repair & maintenance of tissue Involved in collagen formation

Potency verified by GNC procedure #5054. Conforms to USP <2091> for weight. Meets USP <2040> disintegration.

No sugar, no artificial colors, no artificial flavors, no preservatives, sodium free, no wheat, gluten free, no corn, no soy, no dairy.

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take one caplet up to three times per day, an hour before meals or on an empty stomach.

Seals/Symbols

Ko Kosher Service

Formula

Ko Kosher Service

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.

See for yourself

L-Lysine 1000 mg by GNC label

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

What’s inside

The Ingredients in L-Lysine 1000 mg by GNC

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) Servings per container90 Amounts shown are per serving.

L-Lysine

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

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: Povidone, Stearic Acid, Silicon Dioxide, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Lysine 1000 mg by GNC Drug Interactions

Want to check YOUR meds against L-Lysine 1000 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 checker
1Drugs
1 Minor

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in L-Lysine 1000 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-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 1000 mg, from the product label.

GNC

See all GNC products
Name
General Nutrition Corporation
City
Pittsburgh
State
PA
ZipCode
15222
Phone Number
1-888-462-2548
Web Address
gnc.com
Pharmacist Counseling Corner

L-Lysine 1000 mg by GNC: Common Questions

Does L-Lysine 1000 mg by GNC interact with any medications?
Yes. Based on its ingredients, L-Lysine 1000 mg 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 1000 mg 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.
Will L-lysine actually help my cold sores?
L-lysine is possibly effective for cold sores, meaning there's some evidence it may help, but it's not proven to work for everyone. If you want to try it, it's generally well tolerated.
What side effects should I watch for?
The most common side effects are stomach pain, diarrhea, and indigestion. High doses are more likely to cause stomach upset. Long-term safety at high amounts isn't well studied, so stick to typical doses.
Can I take this if I'm pregnant or breastfeeding?
Lysine from food is fine, but supplement safety in pregnancy and breastfeeding hasn't been well studied. There isn't enough reliable data to know either way, so check with your doctor first before taking a supplement.
Does L-lysine work for other conditions, like pressure ulcers or wound healing?
The evidence for pressure ulcers and diabetic foot ulcers is insufficient—we don't have enough reliable data to say whether lysine helps. It's only possibly effective for cold sores.
What's actually in this product besides the lysine?
The other ingredients are povidone, stearic acid, silicon dioxide, and magnesium stearate—all inactive binders and fillers that help make the tablet.

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

Not sure if L-Lysine 1000 mg is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

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 1000 mg label
Go deeper

The Full Monographs Behind L-Lysine 1000 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Sources

Sources & How We Checked

L-Lysine 1000 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.

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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