L-Lysine 500 mg Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Lysine 500 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 500 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.
Check Your Meds Against L-Lysine 500 mg by Best Naturals
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine 500 mg by Best Naturals — 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 500 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.
What’s inside
Full disclosure
This product contains one active ingredient: L-Lysine Hydrochloride, an amino acid your body uses for protein synthesis and immune function. The tablet also includes several inactive ingredients — dicalcium phosphate, microcrystalline cellulose, croscarmellose sodium, stearic acid, magnesium stearate, silicon dioxide, and pharmaceutical glaze — which are binders, fillers, and coating materials that help form and preserve the tablet.
Does it work?
Moderate evidence
L-Lysine is possibly effective for cold sores (herpes labialis) — the evidence supports its use for this purpose. For other uses on the label — child growth, pressure ulcers, and diabetic foot ulcers — we don't have enough reliable evidence in our data to rate whether it works.
How safe is it?
Well-documented data
L-Lysine is generally well tolerated at normal doses. High amounts may cause stomach upset, and long-term safety at high doses hasn't been thoroughly studied.
The most common side effects reported orally are abdominal pain, diarrhea, and indigestion. There is one case report of a person who developed kidney inflammation after oral lysine use, though this is rare.
During pregnancy, lysine from food is fine, but safety of the supplement hasn't been well studied — talk with your doctor before taking it. During breastfeeding, there isn't enough reliable information, so caution is advised; check with your doctor or pharmacist for personalized guidance.
Meds to double-check
Minor interactions only
If you take a 5-HT4 agonist (a medication for certain bowel motility problems), check with your doctor or pharmacist before adding this product — lysine may reduce how well it works. For any other medications, use the search tool on this page to verify there are no interactions we haven't documented.
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 supplement option. If you take medications for bowel motility (5-HT4 agonists), mention this supplement to your doctor or pharmacist first.
At normal doses it's generally well tolerated, though high amounts can upset your stomach. It's worth a conversation with your own healthcare provider before you start, especially if you're pregnant, breastfeeding, or taking other medications.
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
General information
Key facts about L-Lysine 500 mg, straight from the product label.
| Brand | Best Naturals |
|---|---|
| Barcode (UPC) | 817716012179 |
| Net contents | 250 Tablet(s) |
| Market status | On market |
| Date entered into DSLD | Jun 16, 2022 |
| DSLD ID | 269820 |
| 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 |
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 500 mg by Best Naturals, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Lysine Hydrochloride | 500 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.
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 aino 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.
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.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine 500 mg by Best Naturals 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 500 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 container250 Amounts shown are per serving.
L-Lysine Hydrochloride
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 Hydrochloride monograph & interactionsOther (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.
L-Lysine 500 mg by Best Naturals Drug Interactions
HelloPharmacist Interaction Report
L-Lysine 500 mg by Best Naturals has one documented interaction: it may reduce the effects of 5-HT4 agonists (medications that work on a specific serotonin receptor in your gut).
The effect is Minor in severity, based on animal research suggesting lysine acts as a partial blocker of this receptor.
Read the full breakdown — every affected drug type, severity by severity
If you take a 5-HT4 agonist — typically used for certain bowel motility issues — let your doctor or pharmacist know before starting this supplement. They can watch whether your medication remains effective or needs adjustment.
Altogether, these interactions span 1 individual medication.
Use the search tool on this page to check your exact medications, and talk with your doctor or pharmacist before combining them with this product.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Lysine 500 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 500 mg interact with 1 drug. Click any drug to see the details.
1 of the 1 ingredient in L-Lysine 500 mg interact with drugs. Each result below shows which ingredient is responsible. L-Lysine Hydrochloride
TegaserodZelnorm
How Tegaserod interacts with L-Lysine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
L-lysine Hydrochloride5-ht4 Agonists Minor
Interaction Summary
Theoretically, lysine may reduce the effects of 5-HT4 agonists.
Read the full L-lysine Hydrochloride + Tegaserod interactionEach ingredient & the kinds of drugs it affects
For each ingredient in L-Lysine 500 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 Hydrochloride
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 500 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
L-Lysine 500 mg by Best Naturals: Common Questions
Does L-Lysine 500 mg by Best Naturals interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Does L-Lysine actually work for cold sores?
What side effects might I get from this supplement?
Is it safe to take L-Lysine while pregnant?
What about while I'm breastfeeding?
What is L-Lysine actually used for in the body?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Lysine 500 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 500 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 500 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