Methionine is an essential sulfur-containing amino acid used in skincare as an antioxidant and conditioning agent, helping protect proteins and lipids from oxidative damage and supporting skin barrier function. It is generally well tolerated at typical cosmetic concentrations.
| Reported effect | How often | Notes |
|---|---|---|
Mild skin irritation or redness | Rare | Occasional transient irritation, mainly at higher concentrations or on sensitive skin. |
Allergic contact dermatitis | Very rare | Isolated sensitization reports; uncommon for amino acid ingredients. |
Mild stinging on application | Rare | Typically self-limited and formulation-dependent. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.