Ly
Lysine
LysineHydrator
An amino acid added to condition skin and hair. Little research tests what it does on skin.
What it does
It’s one of the amino acids the body can’t make and gets from food. In skin care it’s a conditioning helper, not a headline active.
The evidence, graded
expert consensusUS safety reviewers (2013) assessed α-amino acids, which products use mainly to condition skin and hair. Their index lists phenylalanine, valine, isoleucine and lysine under that report. These amino acids are well established as safe in food, so the reviewers focused on irritation and allergy from use on skin. They judged them safe as used in cosmetics.Burnett 2013 · International Journal of Toxicology ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Also known as
l-lysine
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