Home
/ Product Reviews
/ Lysine

Lysine Supplements Review

Choose the Best Lysine Supplement. CL Tests Reveal Which Lysine Supplements Provide the Best Quality and Value.

Medically reviewed and edited by Tod Cooperman, M.D.

Updated November 07, 2022 Published February 06, 2016

Summary

What is lysine? Lysine (L-lysine) is an essential amino acid found in many protein-rich foods (see Lysine in Food) and is needed for proper growth and other critical functions (see details in What It Is).
What are the health benefits of lysine? As a supplement, lysine may help prevent cold sores (herpes simplex labialis), genital herpes lesions, and canker sores. Although it is also found in topical products for cold sores, it is not known to be active topically (See details in What It Does).
How much lysine to take? Typical daily dosage is 1,000 to 3,000 mg (see details in Quality Concerns).
Lysine has also been used to prevent/treat feline herpesvirus 1 infection — but there is no clinical evidence to support this use and it is not recommended (see details in What It Does, For Cats).
What did CL's tests of lysine find? CL's tests found that all but one product contained their listed amounts of lysine (see details in What CL Found).
Best value for lysine: The cost to obtain lysine from CL Approved products ranged from 4 cents to 33 cents per 1,000 mg (and up to 72 cents for cat products). See which CL Approved products provide the best value.
To compare product test ratings, ingredients, and prices, see the Results Table.
Lysine safety and side effects: People with kidney disease, gallstones, elevated cholesterol, and glutaric acidemia type I should exercise caution with lysine supplements (see details in Concerns and Cautions).

+— 19 sources

In addition the results of its expert testing, ConsumerLab uses only high-quality, evidence based, information sources. These sources include peer-reviewed studies and information from agencies such as the FDA and USDA, and the National Academy of Medicine. On evolving topics, studies from pre-print journals may be sourced. All of our content is reviewed by medical doctors and doctoral-level experts in pharmacology, toxicology, and chemistry. We continually update and medically review our information to keep our content trustworthy, accurate, and reliable. The following sources are referenced in this article:

Make sure you're choosing the best lysine supplements approved in our tests!

See the Full Review as a Member

Join now at www.consumerlab.com/join/

Lysine supplement brands compared in this review

21st Century L-Lysine for Cats

Andrew Lessman ProCaps Lysine

Carlson L-Lysine

CVS/pharmacy L-Lysine

Douglas Laboratories L-Lysine

Finest Nutrition [Walgreens] L-Lysine

GNC L-Lysine

Nature Made L-Lysine

Pet Naturals of Vermont L-Lysine for Cats

Puritan's Pride L-Lysine

Rexall L-Lysine

Rite Aid Pharmacy L-Lysine

Solaray L-Lysine

Solgar L-Lysine

Source Naturals L-Lysine

Spring Valley [Walmart] L-Lysine

Swanson Free-Form L-Lysine

Up & Up [Target] L-Lysine

Vitacost L-Lysine

Vitamin World L-Lysine

In this comprehensive review of lysine supplements, you'll get test results and quality ratings for 17 lysine supplements for people (including 7 that passed our voluntary Quality Certification Program) and two popular lysine supplements for cats. You'll also get information about an additional lysine supplement similar to one that passed testing. You'll learn:

Which lysine supplements passed or failed testing
How lysine supplements compare on quality and cost and which provide the best value.
What lysine can and cannot do for your health, and your cat's health.

How to read the labels, so you know how much lysine you can really expect from a product without being fooled.
Lysine dosage for uses including cold sores, genital herpes lesions and canker sores.
Concerns, drug interactions, and potential side-effects of lysine.

Join to unlock the full report and get full access to over 1,400 reviews

See the Full Review as a Member

Join now at www.consumerlab.com/join/

Reviews & Articles

Membership & Subscription

About ConsumerLab.com

About Testing

News

Lysine Supplements Review

Choose the Best Lysine Supplement. CL Tests Reveal Which Lysine Supplements Provide the Best Quality and Value.

Summary

Make sure you're choosing the best lysine supplements approved in our tests!