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Dietary supplement

L-Lysine 1000 mg Ingredients & Drug Interactions

by Best Naturals

Tablet Or Pill 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 Best Naturals 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 Hydrochloride. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of L-Lysine 1000 mg by Best Naturals

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 hydrochloride at 1000 mg per tablet. L-lysine is an amino acid your body uses for protein building and immune support.

The tablet also includes inactive ingredients such as dicalcium phosphate, microcrystalline cellulose, croscarmellose sodium, stearic acid, magnesium stearate, silicon dioxide, and pharmaceutical glaze—these are fillers and binders that help hold the tablet together.

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: protein production and amino acid supplementation.
  • Our graded evidence for these ingredients doesn't cover that particular purpose.

L-lysine is possibly effective for herpes labialis (cold sores). For other uses listed—child growth, pressure ulcers, and diabetic foot ulcers—the evidence isn't established in our data, meaning either not enough reliable studies exist or the results have been mixed.

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 normal doses. At high amounts, it may cause stomach upset, and long-term safety at high doses hasn't been well studied.

The most common side effects from oral use are abdominal pain, diarrhea, and indigestion. There is one rare case report of kidney inflammation linked to oral lysine, though this is not common.

For pregnancy, supplement lysine safety hasn't been well studied, so talk with your doctor before taking it if you're pregnant. For breastfeeding, there isn't enough reliable information, so caution is advised—discuss it with your doctor or pharmacist.

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 for certain gut conditions), confirm with your doctor or pharmacist before using this product—lysine may reduce how well it works. No other medication interactions are documented for the ingredients we could check.

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.

This supplement may help with cold sores. It's generally well tolerated, but at high doses stomach upset is possible and long-term safety data is limited.

If you take a 5-HT4 agonist medication or are pregnant or breastfeeding, talk with your doctor or pharmacist before starting. Check your exact medications with the search tool on this page.

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 16, 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 L-Lysine 1000 mg, straight from the product label.

Brand Best Naturals
Barcode (UPC) 817716013558
Net contents 180 Tablet(s)
Market status On market
Date entered into DSLD Jun 16, 2022
DSLD ID 270640
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, 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 Best Naturals, 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
180
UPC/BARCODE
817716013558
IngredientAmount% DV
L-Lysine Hydrochloride1000 mg--

Other ingredients: Dicalcium Phosphate, Microcrystalline Cellulose, Croscarmellose Sodium, Stearic Acid, Magnesium Stearate, Silicon Dioxide, Pharmaceutical Glaze

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.
Formula

L-Lysine is an essential amino acid that cannot be manufactured by the body and must be obtained through the diet or by supplementation. Lysine is necessary for the production of all protein in the body including hormones, enzymes, and antibodies, as well as carnitine and collagen, which is the structural protein forming all connective tissue such as skin, tendon, and bone. Certain research publications indicate that it may help support the following: Support healthy calcium absorption. Supports healthy immune system. Supports healthy cardiovascular function.

Precautions

Caution: For adults only, if you are pregnant, nursing, taking any medications or have any medical condition, consult your doctor before use.

Caution: For adults only, if you are pregnant, nursing, taking any medications or have any medical condition, consult your doctor before use. Discontinue use and consult your doctor if any adverse reactions occur.

Keep out of the reach of children.

Do not use if safety seal is broken or missing.

Storage

Keep in 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.

Seals/Symbols

Made in USA

GMP Good Manufacturing Practice Product

Formulation

Premium formula

3rd party lab tested

No artificial color, flavor or sweetener, no preservatives, no sugar, no starch, no milk, no corn, no soy, no egg, no lactose, no gluten, no wheat, no yeast, no fish.

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take one (1) tablet one to three times daily, with or between meals, or as directed by your qualified healthcare professional.

General Statements

For additional information call: 1-877-659-6004

See for yourself

L-Lysine 1000 mg by Best Naturals 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 Best Naturals

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 container180 Amounts shown are per serving.

L-Lysine Hydrochloride

Interacts with
1 drug
1000 mg per serving

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 Hydrochloride monograph & interactions

Other (inactive) ingredients: Dicalcium Phosphate, Microcrystalline Cellulose, Croscarmellose Sodium, Stearic Acid, Magnesium Stearate, Silicon Dioxide, Pharmaceutical Glaze. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Lysine 1000 mg by Best Naturals 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-Lysine Hydrochloride1 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.

Best Naturals

See all Best Naturals products
Name
Best Naturals
Street Address
PO Box 394
City
Kenilworth
State
NJ
ZipCode
07033
Phone Number
1-877-659-6004
Web Address
www.shopbestnaturals.com
Pharmacist Counseling Corner

L-Lysine 1000 mg by Best Naturals: Common Questions

Does L-Lysine 1000 mg by Best Naturals 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 this help my cold sores?
L-lysine is possibly effective for cold sores (herpes labialis), meaning some evidence supports it, though results aren't guaranteed. It's worth trying if you're prone to them, but talk with your doctor about what to expect.
What are the most common side effects?
At normal doses, lysine is generally well tolerated. The most common side effects from oral use are abdominal pain, diarrhea, and indigestion. High amounts may cause more stomach upset.
Is it safe to take while pregnant?
Supplement lysine safety in pregnancy hasn't been well studied, so we don't have enough data either way. Talk with your doctor first before taking it if you're pregnant.
What about breastfeeding?
There isn't enough reliable information on supplement lysine during breastfeeding, so caution is advised. Check with your doctor or pharmacist for personalized advice.
How does lysine work?
Lysine is an amino acid your body uses for protein building and immune support. For cold sores, the exact mechanism isn't fully clear, but evidence suggests it may help reduce outbreak frequency or severity.

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

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

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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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