Cystoseira tamariscifolia is a brown seaweed (algae) whose extract is rich in polyphenols and provides antioxidant and free-radical scavenging activity in cosmetic formulations. It is studied for protective effects against oxidative and UV-induced skin damage.
| Reported effect | How often | Notes |
|---|---|---|
| Contact irritation or mild erythema | Rare | Occasional transient redness or stinging reported in sensitive individuals. |
| Allergic contact dermatitis | Very rare | Hypersensitivity to algal proteins or constituents possible but seldom documented. |
| Iodine sensitivity reactions | Very rare | Marine algae can contain iodine, of theoretical concern for those with iodine allergy or thyroid conditions. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.