Steareth-21 is a polyethylene glycol ether of stearyl alcohol used as a nonionic emulsifier and surfactant to stabilize oil-in-water emulsions and improve texture in skincare formulations. It is a base/formulation ingredient rather than a treatment active.
| Reported effect | How often | Notes |
|---|---|---|
| Mild skin irritation | Uncommon | Possible transient redness or stinging, more likely on compromised or sensitive skin. |
| Allergic contact dermatitis | Rare | Sensitization to PEG-ether emulsifiers has been reported in patch-test studies. |
| Eye irritation | Uncommon | Can cause irritation if products reach the eyes. |
| Concern over 1,4-dioxane traces | Rare | Ethoxylated ingredients may contain trace 1,4-dioxane impurities unless purified; not a direct skin effect. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.