L-Lysine 1 g Unflavored Ingredients & Drug Interactions
by Nutricost
What is this page for?
First and foremost: checking L-Lysine 1 g Unflavored 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 1 g Unflavored is a dietary supplement by Nutricost 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.
Check Your Meds Against L-Lysine 1 g Unflavored by Nutricost
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine 1 g Unflavored by Nutricost — 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 1 g Unflavored by Nutricost
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, an amino acid your body uses to build proteins and fight infection. It comes as an unflavored powder with no other inactive ingredients listed.
Does it work?
Moderate evidence
L-lysine is possibly effective for cold sores (herpes labialis)—evidence supports its use for that purpose. For child growth, pressure ulcers, and diabetic foot ulcers, the evidence isn't established enough to rate it.
How safe is it?
Well-documented data
L-lysine is generally well tolerated at normal doses. High amounts may cause stomach upset, including abdominal pain, diarrhea, and indigestion; long-term safety at high doses hasn't been well studied.
The data on supplement use during pregnancy and breastfeeding is limited, so talk with your doctor or pharmacist before taking it if you're pregnant or nursing.
Meds to double-check
Minor interactions only
If you take a 5-HT4 agonist (a drug that works on serotonin receptors in the gut), confirm with your doctor or pharmacist before adding L-lysine, as it may reduce the drug's effectiveness. No other medication interactions are documented for this ingredient.
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.
If you're looking to manage cold sores, lysine has some evidence behind it. The interaction with 5-HT4 agonists is minor and affects only one medication type, so most people won't be affected—but check your exact medications with your doctor or pharmacist before starting.
Generally well tolerated, though high doses can upset your stomach.
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 Feb 22, 2024.
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 1 g Unflavored, straight from the product label.
| Brand | Nutricost |
|---|---|
| Barcode (UPC) | 702669937740 |
| Net contents | 17.6 Ounce(s); 1.1 lb(s); 500 Gram(s) |
| Market status | On market |
| Date entered into DSLD | Feb 22, 2024 |
| DSLD ID | 306321 |
| Product type | Amino Acid/protein |
| Supplement form | Powder |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Vegetarian, Adult (18 - 50 Years), Gluten 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 1 g Unflavored by Nutricost, 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.
Suggested/Recommended/Usage/Directions
Suggested use: as a dietary supplement, mix 1 scoop daily with 6-10oz of water or as directed by your healthcare professional.
Formulation
Third party tested
Non-GMO Gluten-free
Vegetarian product
Non-GMO product
Precautions
Warning: for healthy individuals 18 years and older. Keep out of reach of children.
Consult a healthcare professional prior to use if you are pregnant or nursing, taking medication, or have a medical condition.
Do not use if safety seal is broken or missing.
Storage
Note: store in a cool, dry place.
General Statements
Contents are sold by weight, not volume. Some settling may occur.
Formula
L-Lysine 1g per serving 500 g per container
FDA Statement of Identity
Dietary Supplement
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
Quality Nutricost Guaranteed
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine 1 g Unflavored by Nutricost 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 1 g Unflavored by Nutricost
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 Gram(s) Dosage formPowder Servings per container500 Amounts shown are per serving.
L-Lysine
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 monograph & interactionsOther (inactive) ingredients: None. These complete the product’s ingredient list but are not active constituents.
L-Lysine 1 g Unflavored by Nutricost Drug Interactions
HelloPharmacist Interaction Report
Nutricost L-Lysine 1 g has one documented interaction—through its L-lysine content with 5-HT4 agonists (a class of drugs that work on serotonin receptors in the gut).
Animal research suggests lysine may reduce how well these drugs work to relieve diarrhea; the interaction is rated Minor. There's only one medication in this category, so the practical impact is narrow, but if you take a 5-HT4 agonist, it's worth confirming with your doctor or pharmacist before starting lysine.
Read the full breakdown — every affected drug type, severity by severity
No interactions are documented for any other drug types. Use the medication checker on this page to look up your exact medications.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Lysine 1 g Unflavored?
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 1 g Unflavored interact with 1 drug. Click any drug to see the details.
1 of the 1 ingredient in L-Lysine 1 g Unflavored interact with drugs. Each result below shows which ingredient is responsible. L-Lysine
TegaserodZelnorm
How Tegaserod interacts with L-Lysine 1 g Unflavored — through 1 ingredient. Tap an ingredient for the detail:
L-lysine5-ht4 Agonists Minor
Interaction Summary
Theoretically, lysine may reduce the effects of 5-HT4 agonists.
Read the full L-lysine + Tegaserod interactionEach ingredient & the kinds of drugs it affects
For each ingredient in L-Lysine 1 g Unflavored 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
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 1 g Unflavored, from the product label.
Nutricost
See all Nutricost products- Name
- Nutricost
- Street Address
- 351 E 1750 N
- City
- Vineyard
- State
- UT
- ZipCode
- 84059
- Phone Number
- (866) 438-3694
- Web Address
- www.nutricost.com
L-Lysine 1 g Unflavored by Nutricost: Common Questions
Does L-Lysine 1 g Unflavored by Nutricost 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 notice?
Is it safe during pregnancy or breastfeeding?
Can I take this if I have kidney problems?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Lysine 1 g Unflavored 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 1 g Unflavored’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 1 g Unflavored'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