L-Lysine Ingredients & Drug Interactions
by Hard Rhino
What is this page for?
First and foremost: checking L-Lysine 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 is a dietary supplement by Hard Rhino 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 by Hard Rhino
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine by Hard Rhino — 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 by Hard Rhino
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
Hard Rhino's L-Lysine Powder contains one active ingredient: L-Lysine Hydrochloride, an amino acid your body uses to build and repair tissues. The product contains no inactive fillers or other ingredients—it's lysine only.
Does it work?
Moderate evidence
The evidence shows L-Lysine is possibly effective for herpes labialis (cold sores). For other uses—child growth, pressure ulcers, and diabetic foot ulcers—there isn't enough reliable evidence to rate how well it works.
How safe is it?
Well-documented data
L-Lysine is generally well tolerated at typical doses. High amounts may cause stomach upset, and long-term safety of supplement doses is not well studied.
The most common side effects reported are abdominal pain, diarrhea, and indigestion. There is one case report of oral lysine linked to kidney inflammation progressing to chronic kidney failure, though this is rare.
Lysine from food is safe in pregnancy, but the safety of supplement doses during pregnancy is not well studied—check with your doctor first. There isn't enough reliable information on supplement use while breastfeeding, so caution is advised and you should talk with your doctor or pharmacist.
Meds to double-check
Minor interactions only
If you take a 5-HT4 agonist (a type of medication affecting serotonin receptors in the gut), check with your doctor or pharmacist before starting L-Lysine—it may reduce how well your medication works.
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 is a straightforward single-ingredient supplement possibly helpful for cold sores. If you take a 5-HT4 agonist, confirm with your doctor or pharmacist that lysine won't interfere with it.
Talk it over with your own healthcare provider to make sure it fits your situation.
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 Apr 25, 2017.
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, straight from the product label.
| Brand | Hard Rhino |
|---|---|
| Barcode (UPC) | 818136462872 |
| Net contents | 125 Gram(s); 4.4 Oz(s) |
| Market status | On market |
| Date entered into DSLD | Apr 25, 2017 |
| DSLD ID | 72617 |
| Product type | Amino Acid/protein |
| Supplement form | Powder |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Gluten Free, Dairy 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 by Hard Rhino, sourced from the NIH Dietary Supplement Label Database.
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.
Formulation
No added fillers
Allergens: This product contains no soy, dairy, dairy byproducts, eggs, shellfish, wheat, gluten, tree nuts, or sesame seeds.
This is a non-GMO ingredient.
General Statements
Only pure ingredients
Pure powder
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement, take 500 mg (~1/4 tsp) with 8 ounces of water or suitable beverage. Taken 1-3 times daily or as directed by your qualified health professional.
1 Carefully measure out suggested serving size using a microscale. 2 Add to preferred beverage. 3 Mix well. 4 Drink within 10-15 minutes. How to use
Storage: Store in a cool, dry place. Re-seal zipper immediately after use to preserve freshness.
FDA Disclaimer Statement
These statements have not been evaluated by the Food & Drug Administration. This product is not intended to diagnose, treat, cure or prevent any diseases.
Precautions
Warning: Keep out of the reach of children. Do not take this or any other supplement if under the age of 18, pregnant or nursing a baby, or if you have any known or suspected medical conditions and/or taking prescription drug(s) or OTC medication(s).
Do not take this or any other supplement if under the age of 18, pregnant or nursing a baby, or if you have any known or suspected medical conditions and/or taking prescription drug(s) or OTC medication(s).
Always consult with a qualified health physician before taking any new dietary supplement.
Do not use or consume if pressure seal is broken.
Do not use or consume if seal is broken.
Seals/Symbols
Lab tested for purity and quality
Packaged in USA
FDA Statement of Identity
Dietary Supplement
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine by Hard Rhino 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 by Hard Rhino
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size0.5 Gram(s) Dosage formPowder 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: None. These complete the product’s ingredient list but are not active constituents.
L-Lysine by Hard Rhino Drug Interactions
HelloPharmacist Interaction Report
L-Lysine by Hard Rhino interacts with a small medication category.
Through its lysine content, it may reduce the effects of 5-HT4 agonists (a class of drugs that work on serotonin receptors). Animal research suggests lysine acts as a partial blocker of the 5-HT4 receptor, which could theoretically lower how well these medications work—a Minor interaction.
Read the full breakdown — every affected drug type, severity by severity
If you take a 5-HT4 agonist, check your exact medication with your doctor or pharmacist before starting lysine.
Additionally, we hold no interaction data for other drug categories with lysine. Altogether, these interactions span 1 individual medication.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Lysine?
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 interact with 1 drug. Click any drug to see the details.
1 of the 1 ingredient in L-Lysine interact with drugs. Each result below shows which ingredient is responsible. L-Lysine Hydrochloride
TegaserodZelnorm
How Tegaserod interacts with L-Lysine — 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 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, from the product label.
Hard Rhino
See all Hard Rhino products- Name
- Guardian Wholesale
- Street Address
- 1607 West Whispering Wind Drive
- City
- Phoenix
- State
- AZ
- ZipCode
- 85085
- Phone Number
- (866) 961-8378
- Web Address
- HardRhino.com
L-Lysine by Hard Rhino: Common Questions
Does L-Lysine by Hard Rhino interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Does L-Lysine work for cold sores?
What are the side effects?
Is it safe to take during pregnancy?
Is it safe while breastfeeding?
Why is this just lysine with no other ingredients?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Lysine 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’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'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