L-Lysine 1000 mg Ingredients & Drug Interactions
by Nutricost
What is this page for?
First and foremost: checking L-Lysine 1000 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 1000 mg is a dietary supplement by Nutricost 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 1000 mg by Nutricost
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine 1000 mg by Nutricost — 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 1000 mg by Nutricost
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 your body uses to build and repair tissues, including skin and immune cells. You're getting 1,000 mg per capsule.
The capsule also holds three inactive ingredients—rice flour, gelatin, and stearic acid—which are just fillers and binders to hold the product together.
Does it work?
Moderate evidence
L-lysine is possibly effective for herpes labialis (cold sores) based on available evidence. For other uses—child growth, pressure ulcers, and diabetic foot ulcers—we don't have enough reliable evidence yet to rate how well it works.
If you're considering it for cold sores, talk with your doctor about whether it fits your treatment plan.
How safe is it?
Well-documented data
L-lysine from food sources is fine, and oral supplements are generally well tolerated at typical doses. High amounts may cause stomach upset, including abdominal pain, diarrhea, and indigestion.
Long-term safety at supplement levels hasn't been thoroughly studied. In pregnancy, lysine from food is not a concern, but supplement use hasn't been well studied—check with your doctor first.
For breastfeeding, there isn't enough reliable information, so caution is advised and a conversation with your pharmacist or doctor makes sense.
Meds to double-check
Minor interactions only
Before you start L-lysine, double-check if you take a 5-HT4 agonist (a medication sometimes used for digestive motility issues). Lysine may reduce how well these drugs work, so your doctor or pharmacist should know you're considering this supplement.
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 might help with cold sores if you're looking for an evidence-based option. It's generally well tolerated, but high doses can cause digestive upset.
If you take a 5-HT4 agonist medication, confirm with your doctor or pharmacist that this supplement won't interfere. Pregnant or breastfeeding—talk it over with 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 Jun 24, 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 1000 mg, straight from the product label.
| Brand | Nutricost |
|---|---|
| Barcode (UPC) | 702669937511 |
| Net contents | 250 Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Jun 24, 2020 |
| DSLD ID | 223395 |
| Product type | Amino Acid/protein |
| Supplement form | Capsule |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Gluten 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 1000 mg by Nutricost, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Lysine | 1000 mg | -- |
Other ingredients: Rice Flour, Gelatin Capsules, Stearic Acid
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
Recommended Use: As a dietary supplement, take 2 capsules with 8-12 oz of water, or as directed by your physician.
Precautions
Warning: This product is only intended to be consumed by healthy individuals 18 years of age or older.
Consult your physician prior to use if you are pregnant or nursing.
Do not exceed recommended use. Improper use will not improve results and is not advised.
Keep out of reach of children.
Do not use if safety seal is broken.
Storage
Notice: Store in a cool, dry place.
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.
FDA Statement of Identity
Dietary Supplement
Formula
L-Lysine as (L-Lysine Hydrochloride) 1,000 mg per serving
Seals/Symbols
Nutricost Quality guaranteed 3rd party tested
Formulation
Non GMO Gluten free product
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine 1000 mg by Nutricost 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 1000 mg by Nutricost
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size2 Capsule(s) Dosage formCapsule Servings per container125 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: Rice Flour, Gelatin Capsules, Stearic Acid. These complete the product’s ingredient list but are not active constituents.
L-Lysine 1000 mg by Nutricost Drug Interactions
HelloPharmacist Interaction Report
Nutricost L-Lysine 1000 mg has documented interactions through its single active ingredient, L-lysine.
The most serious concern is with 5-HT4 agonists (a class of medications used for certain digestive issues), where lysine may theoretically reduce how well these drugs work. Animal research suggests lysine acts as a partial antagonist to the serotonin receptor these drugs target, though human evidence is limited.
Read the full breakdown — every affected drug type, severity by severity
Although we have interaction data for L-lysine, the documented interactions span only 1 individual medication type. If you take a 5-HT4 agonist, check with your doctor or pharmacist before starting this supplement to see if timing or dosing adjustments make sense for you.
Check your own medications below · Editorial policy · How we use AI
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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in L-Lysine 1000 mg interact with 1 drug. Click any drug to see the details.
1 of the 1 ingredient in L-Lysine 1000 mg interact with drugs. Each result below shows which ingredient is responsible. L-Lysine
TegaserodZelnorm
How Tegaserod interacts with L-Lysine 1000 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 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-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 1000 mg, from the product label.
Nutricost
See all Nutricost products- Name
- Nutricost
- Street Address
- 351 E 1750 N
- City
- Vineyard
- State
- UT
- ZipCode
- 84059
- Phone Number
- (866) 438-3694
- Web Address
- www.nutricost.com
L-Lysine 1000 mg by Nutricost: Common Questions
Does L-Lysine 1000 mg by Nutricost 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?
Can I take L-lysine while pregnant?
What side effects might I get from L-lysine?
Is it safe to take L-lysine for a long time?
Can I breastfeed while taking L-lysine?
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.
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 1000 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 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.
- 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