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Lysine: Does It Work for Cold Sores and Which Brands Are Best?

— Reviews the Evidence and Tests Supplements Often Used to Prevent Herpes Eruptions —
White Plains, New York, February 9, 2016 — Lysine is an essential amino acid often taken as a supplement to prevent cold sores, genital herpes lesions, and canker sores. It's also given to cats with feline herpesvirus 1. But does it really work? And which products are best? To find out, recently selected and purchased twelve lysine supplements and tested them to see whether they contained their claimed amounts of lysine and if tablets could properly release their contents.'s review revealed that labeling of one product was misleading and provided only 83.2% of the lysine one might expect from its label. CL also found significant differences in the cost to get lysine from products, which, for the same dose ranged from 4 cents to 33 cents. Among the products which were Approved for Quality by (including seven products tested through CL's voluntary Quality Certification Program), those offering the best value were identified.

Two lysine chews for cats were also tested, one of which provided lysine at a much lower cost than the other.'s Lysine Supplements Review is now available online at The report summarizes the clinical evidence regarding the use of lysine in people and in cats, including information about safety, side-effects and dosage, what to look for on labels, and tests and comparisons the following products: Andrew Lessman ProCaps Lysine-400, Carlson L-Lysine, CVS/pharmacy L-Lysine, Douglas Laboratories L-Lysine, Finest Nutrition [Walgreens] L-Lysine, GNC L-Lysine, Nature Made L-Lysine, Puritan's Pride L-Lysine, Rexall L-Lysine, Rite Aid Pharmacy L-Lysine, Solaray L-Lysine, Solgar L-Lysine 1000 mg, 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, 21st Century L-Lysine -- All Cats and Pet Naturals of Vermont L-Lysine for Cats.

Founded in 1999, is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. Membership to is available online and provides immediate access to reviews of more than 1,000 products from over 400 brands. The company is privately held and based in Westchester, New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products.

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