L-Lysine Pure Powder Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Lysine Pure Powder 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 Pure Powder 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 Pure Powder by Best Naturals
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Lysine Pure Powder 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 Pure Powder 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
L-Lysine Pure Powder is straightforward — it contains a single active ingredient, L-lysine hydrochloride, in powder form. L-lysine is an amino acid (a building block of protein) that your body either makes or gets from food sources like meat, dairy, and legumes.
Does it work?
Moderate evidence
The evidence is strongest for cold sores: lysine is rated possibly effective for reducing how often you get them and how severe they are when you do. For other uses — child growth, pressure ulcers, and diabetic foot ulcers — the evidence we hold is insufficient to say whether it works.
If you're thinking about lysine for something beyond cold sores, talk with your doctor about what the current science supports.
How safe is it?
Well-documented data
L-lysine is generally well tolerated at normal doses. The most common side effects from taking it by mouth are stomach upset — abdominal pain, diarrhea, and indigestion — though these happen in a minority of people.
High doses may cause more stomach trouble, and long-term safety at large amounts hasn't been well studied. For pregnancy: supplement safety during pregnancy hasn't been well studied, so talk with your doctor before taking it while pregnant.
For breastfeeding: there isn't enough reliable information to know how safe it is, so caution is advised and you should discuss it with your doctor or pharmacist. Lysine from food is fine during both.
Meds to double-check
Minor interactions only
If you take a 5-HT4 agonist (a medication for certain digestive disorders), check with your doctor or pharmacist before starting this product — lysine may reduce its effectiveness. No other medication interactions are documented in our data for the ingredients we hold.
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 is possibly effective for cold sores and is generally well tolerated in typical amounts, though it can cause stomach upset in some people. If you take a 5-HT4 agonist, check with your doctor or pharmacist before starting.
If you're pregnant or breastfeeding, talk with your healthcare provider about whether this supplement is right for you.
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 Pure Powder, straight from the product label.
| Brand | Best Naturals |
|---|---|
| Barcode (UPC) | 817716014579 |
| Net contents | 1 lb(s); 454 Gram(s) |
| Market status | On market |
| Date entered into DSLD | Jun 16, 2022 |
| DSLD ID | 270641 |
| Product type | Amino Acid/protein |
| Supplement form | Powder |
| 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 Pure Powder by Best Naturals, 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.
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 L-Lysine 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
Bottled 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 corn, no soy, no egg, no milk, no lactose, no gluten, no wheat, no yeast, no fish. Sodium free.
FDA Statement of Identity
Dietary Supplement
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement, take 1/4 level teaspoon daily, preferably with meals.
General Statements
For additional information call: 1-877-659-6004
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Lysine Pure Powder 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 Pure Powder by Best Naturals
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size552 mg Dosage formPowder Servings per container822 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 Pure Powder by Best Naturals Drug Interactions
HelloPharmacist Interaction Report
L-Lysine Pure Powder by Best Naturals contains one ingredient — L-lysine hydrochloride — that has a documented interaction.
The most serious interaction is Minor in severity: lysine may reduce the effects of 5-HT4 agonists (a class of medications used for certain gastrointestinal conditions). Animal research suggests lysine acts as a partial blocker of the serotonin receptor 4 (5-HT4), which could theoretically lower how well these drugs work.
Read the full breakdown — every affected drug type, severity by severity
Although this is the only interaction category documented in our data, it affects one individual medication type. If you take a 5-HT4 agonist, check with your doctor or pharmacist before starting lysine to see if timing or dosing changes make sense for you.
You can use the search tool on this page to look up your exact medications and see if any interact with lysine.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Lysine Pure Powder?
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 Pure Powder interact with 1 drug. Click any drug to see the details.
1 of the 1 ingredient in L-Lysine Pure Powder interact with drugs. Each result below shows which ingredient is responsible. L-Lysine Hydrochloride
TegaserodZelnorm
How Tegaserod interacts with L-Lysine Pure Powder — 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 Pure Powder 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 Pure Powder, 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 Pure Powder by Best Naturals: Common Questions
Does L-Lysine Pure Powder 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 really help with cold sores?
What side effects should I expect?
Is it safe to take long-term?
Can I take this while pregnant or breastfeeding?
Is this the same as lysine from food?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Lysine Pure Powder 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 Pure Powder’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 Pure Powder'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