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Dietary supplement

Lysine 1000 mg Ingredients & Drug Interactions

by Nature's Blend

Lysine 1000 mg label
See full label image
Tablet Or Pill Category: Amino Acid/protein
Most serious interaction: Minor
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking 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

The interaction bottom line Most serious interaction: Minor

Lysine 1000 mg is a dietary supplement by Nature's Blend 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.

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Check Your Meds Against Lysine 1000 mg by Nature's Blend

Ask about any prescription or over-the-counter medication and we check it for interactions with Lysine 1000 mg by Nature's Blend — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Lysine 1000 mg by Nature's Blend

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

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

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 for protein synthesis, immune function, and tissue repair. The inactive ingredients are stearic acid, cellulose, croscarmellose sodium, magnesium stearate, and silica — these are binders, fillers, and flow agents that help form the tablet.

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

This product doesn't appear to be marketed for a specific use, so we graded Lysine's overall clinical evidence instead.

Moderate

Some clinical evidence supports Lysine for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Herpes labialis (cold sores) — rated "Possibly Effective" (Natural Medicines).

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, we don't have enough reliable evidence to rate how well 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.

Lysine is generally well tolerated at typical doses. At higher amounts, you may experience stomach upset, abdominal pain, diarrhea, or indigestion.

Long-term safety at high doses hasn't been well studied. For pregnancy, the safety of lysine supplements hasn't been well studied, so talk with your doctor first — lysine from food is fine, but supplements are a different question.

There also isn't enough data on safety while breastfeeding, so caution is advised and discussion with your doctor or pharmacist is a good idea.

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 works on serotonin receptor 4 for GI conditions), check with your pharmacist before adding this — lysine may reduce how well it works. For all other medications, no interactions are documented in our data, but always verify your exact medications with the tool on this page.

Check your own medication Run your meds through the checker above

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.

Lysine may be worth trying if you get cold sores and want to see if it helps prevent or shorten outbreaks. If you're taking a 5-HT4 agonist or are pregnant or breastfeeding, check with your pharmacist first.

For most people at standard doses, it's well tolerated, but stick to the label dose and watch for stomach trouble.

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 Nov 22, 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

At a glance

General information

Key facts about Lysine 1000 mg, straight from the product label.

Brand Nature's Blend
Barcode (UPC) 079854600605
Net contents 50 Tablet(s)
Market status On market
Date entered into DSLD Nov 22, 2022
DSLD ID 274676
Product type Amino Acid/protein
Supplement form Tablet Or Pill
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Lysine 1000 mg by Nature's Blend, 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 Tablet(s)
Maximum serving Sizes:
1 Tablet(s)
Servings per container
50
UPC/BARCODE
079854600605
IngredientAmount% DV
L-Lysine1000 mg--

Other ingredients: Stearic Acid, Cellulose, Croscarmellose Sodium, 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.
Storage

Store in a cool, dry place.

Precautions

Keep out of the reach of children.

Double safety sealed for your protection. Do not use if either seal is broken or missing.

Formulation

Preservative & gluten free. No sugar, starch, artificial colors, artificial flavors, wheat, yeast, or corn added.

This product is manufactured under strict quality control guidelines; therefore, purity and label potency are guaranteed. Made in USA & American Owned

General Statements

Questions/Comments Call 1-800-682-9862

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take one tablet daily, preferably with a meal or as directed by your healthcare professional.

Formula

L-lysine is an essential amino acid. L-lysine may play a role in immune system support.

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 disease.

Seals/Symbols

Lab Tested Potency Assay Guaranteed Release

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Lysine 1000 mg by Nature's Blend label

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

Lysine 1000 mg label

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)
What’s inside

The Ingredients in Lysine 1000 mg by Nature's Blend

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Tablet(s) Dosage formTablet Or Pill Servings per container50 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: Stearic Acid, Cellulose, Croscarmellose Sodium, Magnesium Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Lysine 1000 mg by Nature's Blend Drug Interactions

Want to check YOUR meds against 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

L-Lysine 1

Individual Drug Interactions

The ingredients in Lysine 1000 mg interact with 1 drug. Click any drug to see the details.

1 of the 1 ingredient in Lysine 1000 mg interact with drugs. Each result below shows which ingredient is responsible. L-Lysine

Each ingredient & the kinds of drugs it affects

For each ingredient in 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
L-Lysine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Lysine 1000 mg, from the product label.

Nature's Blend

See all Nature's Blend products
Name
National Vitamin Company
City
Casa Grande
State
AZ
ZipCode
85122
Phone Number
1-800-682-9862
Web Address
www.nationalvitamin.com
Pharmacist Counseling Corner

Lysine 1000 mg by Nature's Blend: Common Questions

Does Lysine 1000 mg by Nature's Blend interact with any medications?
Yes. Based on its ingredients, 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?
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.
Does lysine actually work for cold sores?
The evidence suggests it's possibly effective — some research supports it, but we'd like to see more studies. Many people try it, and some do find it helpful for preventing outbreaks or shortening them. Your results may vary.
What side effects should I watch for?
Lysine is generally well tolerated, but at higher doses you might notice stomach pain, diarrhea, or indigestion. Start at the label dose and stay there unless your doctor says otherwise.
Is it safe to take lysine while pregnant?
The safety of lysine supplements in pregnancy hasn't been well studied. Lysine from food is fine, but talk with your doctor before taking a supplement — they know your individual situation and can give you personalized advice.
Can I take this while breastfeeding?
There isn't enough reliable information on supplement use while breastfeeding. Check with your doctor or pharmacist first — they'll help you decide if it's right for you.
How much lysine should I take?
Follow the dose on the label. The facts we have show that high amounts may cause stomach upset, so don't exceed the recommended amount without talking to your pharmacist.

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

Not sure if 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.

Lysine 1000 mg label
Go deeper

The Full Monographs Behind Lysine 1000 mg’s Ingredients

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

Herb & supplement monograph

Lysine

Interacts with 1 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 try to prevent or shorten cold sores, but...

Read the full Lysine monograph →
Sources

Sources & How We Checked

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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