Acetyl Tetrapeptide-11 is a synthetic peptide marketed to support skin firmness by stimulating syndecan-1 and collagen-anchoring proteins, helping reinforce the dermal-epidermal junction. It is typically used in leave-on cosmetic formulations at low concentrations for firming and elasticity claims.
| Reported effect | How often | Notes |
|---|---|---|
| Mild localized irritation or redness | Rare | Transient and generally formulation-dependent rather than intrinsic to the peptide. |
| Contact allergy or sensitization | Very rare | Few documented cases; peptides are generally considered low-sensitizing. |
| Stinging or itching on application | Rare | More often linked to other formulation components such as solvents or preservatives. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.