L-Lysine HCL Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Lysine HCL 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 HCL is a dietary supplement by BulkSupplements.com 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 HCL by BulkSupplements.com
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine HCL by BulkSupplements.com — 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
Ask the Pharmacist
A licensed pharmacist will answer your question by email — free, usually within 24 hours.
Got it — thank you!
A licensed pharmacist will answer within 24 hours. Keep an eye on your email (worth checking spam, just in case).
HelloPharmacist Scorecard of L-Lysine HCL by BulkSupplements.com
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 to build protein and support immune function. There are no inactive ingredients listed.
Does it work?
Moderate evidence
L-lysine is possibly effective for cold sores (herpes labialis). For other uses on file—child growth, pressure ulcers, and diabetic foot ulcers—the evidence isn't established enough in our data to rate it either way.
How safe is it?
Well-documented data
L-lysine is generally well tolerated at typical doses. High amounts may cause stomach upset, including abdominal pain, diarrhea, and indigestion, and long-term safety at high doses isn't well studied.
There's one case report of high-dose oral lysine linked to kidney inflammation that progressed to chronic kidney failure, though this is rare. Supplement safety in pregnancy and while breastfeeding hasn't been well studied—lysine from food is fine, but if you're pregnant or nursing, talk with your doctor before taking a supplement.
Meds to double-check
Minor interactions only
5-HT4 agonists are the main medication class to double-check before taking this product—lysine may reduce how well they work. If you take one, confirm it's okay with your doctor or pharmacist.
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 may help with cold sores. It's generally well tolerated at normal doses, though high amounts can cause stomach upset.
If you're pregnant, nursing, or take a 5-HT4 agonist, check with your doctor or pharmacist first. Run your exact medications through the tool below to be sure.
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 Oct 22, 2021.
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 HCL, straight from the product label.
| Brand | BulkSupplements.com |
|---|---|
| Barcode (UPC) | X000HHF73H |
| Net contents | 500 g; 17.6 oz |
| Market status | On market |
| Date entered into DSLD | Oct 22, 2021 |
| DSLD ID | 254610 |
| 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 HCL by BulkSupplements.com, 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.
General Statements
Clean & pure bulk supplements
FDA Disclaimer Statement
Warning: This product is not intended to diagnose, treat, cure, or prevent any disease.
Precautions
Always consult a physician before taking any dietary supplement.
Keep out of reach of children.
Formulation
Free of: Added sugar, soy, dairy, yeast, gluten, additives
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement, take 750 mg (about 1/3 tsp) once or twice daily, or as directed by a physician.
Storage
Store in a dry, cool place
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine HCL by BulkSupplements.com 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 HCL by BulkSupplements.com
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size750 Milligram(s) Dosage formPowder Servings per container667 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 HCL by BulkSupplements.com Drug Interactions
HelloPharmacist Interaction Report
L-Lysine HCL by BulkSupplements.com has one documented interaction.
Through its L-lysine hydrochloride content, it may reduce the effects of 5-HT4 agonists (a class of drugs that work on serotonin receptors in the gut). Animal research suggests lysine acts as a partial blocker of these receptors, which could theoretically make these medications less effective.
Read the full breakdown — every affected drug type, severity by severity
If you take a 5-HT4 agonist, check with your doctor or pharmacist before starting this supplement. 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 HCL?
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 HCL interact with 1 drug. Click any drug to see the details.
1 of the 1 ingredient in L-Lysine HCL interact with drugs. Each result below shows which ingredient is responsible. L-Lysine Hydrochloride
TegaserodZelnorm
How Tegaserod interacts with L-Lysine HCL — 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 HCL 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 HCL, from the product label.
BulkSupplements.com
See all BulkSupplements.com products- Name
- BulkSupplements.com
- Street Address
- 7511 Eastgate Rd
- City
- Henderson
- State
- NV
- ZipCode
- 89011
- Web Address
- BulkSupplements.com
L-Lysine HCL by BulkSupplements.com: Common Questions
Does L-Lysine HCL by BulkSupplements.com interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Does L-lysine really help with cold sores?
What side effects should I watch for?
Is it safe to take while pregnant?
Can I take this while breastfeeding?
How much L-lysine is in one serving?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Lysine HCL 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 HCL’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 HCL'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