Me
Methionine
MethionineHydrator
A sulfur-containing 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. The EU lists it as a skin and hair conditioner that also cuts static.
The evidence, graded
expert consensusUS safety reviewers (2013) assessed the amino acids used in cosmetics, mainly to condition skin and hair; their index lists glycine, proline, serine, alanine, histidine and glutamic acid under that report, and its conclusion list names leucine and methionine. Their safety as food is well established, so the reviewers focused on skin irritation and allergy, and judged them safe as used.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-methionine
Browse all 1238 ingredients — grouped by what they do, each with whatever evidence we can cite.
This page is public so a shared ingredient card always has its sources behind it — and so you can check them without an account.
Want more like this?
Every evidence-based flag cites its source, Drop tells you when your routine is complete, and it helps you simplify — instead of selling you more. The app launches on iOS and Android in October 2026. Rate my routine works today at /rate — no sign-in.