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Dietary supplement

Lysine 350 Ingredients & Drug Interactions

by ProCaps

Lysine 350 label
See full label image
Capsule Category: Amino Acid/protein
Most serious interaction: Minor
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Lysine 350 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

The interaction bottom line Most serious interaction: Minor

Lysine 350 is a dietary supplement by ProCaps 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.

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Check Your Meds Against Lysine 350 by ProCaps

Ask about any prescription or over-the-counter medication and we check it for interactions with Lysine 350 by ProCaps — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Lysine 350 by ProCaps

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.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Lysine 350 contains one active ingredient: L-lysine, an amino acid your body uses for protein synthesis and immune function. The capsule is made with gelatin as an inactive ingredient.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: immune supportive amino acid.
  • We looked for evidence on: Herpes labialis (cold sores), Genital herpes, Protein synthesis, Calcium metabolism.
  • The strongest evidence on file: Lysine is rated "Possibly Effective" for Herpes labialis (cold sores) (Natural Medicines).

Lysine is possibly effective for cold sores (herpes labialis). For other uses — child growth, pressure ulcers, and diabetic foot ulcers — the evidence we hold isn't strong enough to rate it either way.

The evidence, ingredient by ingredient Lysine

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Lysine is generally well tolerated at typical doses. However, high amounts may cause stomach upset (abdominal pain, diarrhea, or indigestion), and long-term safety at supplement doses isn't well studied.

There's one case report of oral lysine linked to kidney inflammation, though this is rare. Supplement safety in pregnancy and breastfeeding hasn't been well studied, so talk with your doctor or pharmacist before using lysine if you're pregnant or nursing.

Lysine from food is fine — the caution applies to supplements.

Side effects, ingredient by ingredient Lysine

Meds to double-check

Minor interactions only
Known Interaction Concern · database check
Minor only

Only Minor-severity interactions are documented for these ingredients.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Lysine.
  • The most serious interaction on file is rated Minor.
  • For scale: 1 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take a 5-HT4 agonist (a medication that acts on serotonin receptors in the gut), check with your pharmacist before adding lysine — it may reduce the drug's effectiveness.

Check your own medication Run your meds through the checker above

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 have cold sores and want to try lysine, this product is generally well tolerated at normal doses. If you take a 5-HT4 agonist or have kidney concerns, check with your pharmacist first.

Pregnant or breastfeeding? Talk to your doctor before starting.

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 May 21, 2025.

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

At a glance

General information

Key facts about Lysine 350, straight from the product label.

Brand ProCaps
Barcode (UPC) 893234
Net contents 360 Easy-To-Swallow Capsule(s)
Market status On market
Date entered into DSLD May 21, 2025
DSLD ID 331573
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), No Allergies, Gluten Free, Dairy Free, Sugar Free
From the label
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 Lysine 350 by ProCaps, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
360
UPC/BARCODE
893234
IngredientAmount% DV
L-Lysine350 mg--

Other ingredients: Gelatin

Tap any ingredient to jump to its full detail below.

Label statements
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 Consume one capsule daily. You can increase your intake as required or as guided by your physician.

General Statements

For questions about the use of this product call 800.800.1200. Questions? Reorders? 800.800.1200 Procaps.com

Andrew Lessman

Formulation

Since 1979, Unsurpassed purity, quality and efficacy. 100% solar production Zero-carbon footprint

100% Solar

Contains no additives or common allergens Contains no milk, soy, yeast, corn, wheat, gluten, sodium, salt, sugar, fat, cholesterol, color, preservative, common allergens, genetically modified (GMO) ingredients or manufacturing additives.

Brand IP Statement(s)

Copyright 2024 ProCaps Laboratories

Formula

Immune supportive amino acid

Lysine 350 is a pure, natural source of the essential amino acid L-Lysine. Lysine is among the most frequently supplemented amino acids, because of its established role in immune system support, as well as its central role in fat burning and energy metabolism. Lysine is one of only nine Amino acids referred to as essential because it cannot be produced by the body and is only available through diet or supplementation. Lysine is vital for the growth and development of all body tissues and is central to the production of energy, since it is a precursor to acetyl CoA synthesis - a critical component of all energy metabolism. Additionally, Lysine is also required to create Carnitine, which is necessary for all fat metabolism. Lysine also plays an important structural role in the formation of collagen - the basic protein structure of skin, bones, joints and connective tissue (tendons, ligaments and cartilage). In short, Lysine is among the most important of our body's amino acids playing a multitude of critical roles in the most vital systems in our body.

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.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Lysine 350 by ProCaps label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Lysine 350 label

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)
What’s inside

The Ingredients in Lysine 350 by ProCaps

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container360 Amounts shown are per serving.

L-Lysine

Interacts with
1 drug
350 mg per serving Form: L-Lysine Hydrochloride

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 & interactions

Other (inactive) ingredients: Gelatin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Lysine 350 by ProCaps Drug Interactions

Want to check YOUR meds against Lysine 350?

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 checker
1Drugs
1 Minor

Ingredients driving the most interactions

L-Lysine 1

Individual Drug Interactions

The ingredients in Lysine 350 interact with 1 drug. Click any drug to see the details.

1 of the 1 ingredient in Lysine 350 interact with drugs. Each result below shows which ingredient is responsible. L-Lysine

Each ingredient & the kinds of drugs it affects

For each ingredient in Lysine 350 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-Lysine1 drug type · 1 drug

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.

Likelihood Unlikely Evidence D
L-Lysine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Lysine 350, from the product label.

ProCaps

See all ProCaps products
Name
ProCaps Labs
City
Henderson
State
NV
ZipCode
89011
Phone Number
800.800.1200
Web Address
ProCaps.com
Pharmacist Counseling Corner

Lysine 350 by ProCaps: Common Questions

Does Lysine 350 by ProCaps interact with any medications?
Yes. Based on its ingredients, Lysine 350 has a known interaction with 1 medication. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Lysine 350 contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Will lysine help my cold sores?
Lysine is possibly effective for cold sores, so it's worth trying if you're prone to them. Results vary person to person, and the evidence is promising but not yet definitive.
What side effects might I see?
Stomach upset — abdominal pain, diarrhea, or indigestion — is the most common issue, especially at higher doses. It's generally well tolerated, but high amounts may cause discomfort.
Is lysine safe if I'm pregnant?
Supplement safety in pregnancy hasn't been well studied. Lysine from food is fine, but if you're thinking about taking a supplement, talk with your doctor first so they can advise you personally.
Can I take it while breastfeeding?
There isn't enough reliable information on supplement lysine during breastfeeding. Check with your doctor or pharmacist for personalized advice.
How much lysine is in each capsule?
Each capsule contains 350 mg of L-lysine.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Lysine 350 is safe with your meds?

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Ask a pharmacist

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.

Lysine 350 label
Go deeper

The Full Monographs Behind Lysine 350’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Lysine

Interacts with 1 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 try to prevent or shorten cold sores, but...

Read the full Lysine monograph →
Sources

Sources & How We Checked

Lysine 350'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.

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
  1. 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
  2. McCune MA, Perry HO, Muller SA, O'Fallon WM. Treatment of recurrent herpes simplex infections with L-lysine monohydrochloride. Cutis 1984;34:366-73.
  3. DiGiovanna JJ, Blank H. Failure of lysine in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Arch Dermatol 1984;120:48-51. DOI
  4. 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.
  5. 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
  6. 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
  7. 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.

See these in context on the Lysine monograph →

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

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