Ergothioneine is a naturally occurring, sulfur-containing amino acid derivative used in skincare as a potent antioxidant that helps protect skin cells from oxidative stress and may support skin barrier function. It is valued for its stability and ability to scavenge free radicals.
| Reported effect | How often | Notes |
|---|---|---|
| Mild skin irritation or redness | Rare | Generally well tolerated; transient irritation possible in sensitive individuals. |
| Contact allergy or sensitization | Very rare | Allergic reactions are uncommonly reported in topical use. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.