Terephthalidene Dicamphor Sulfonic Acid (ecamsule, also marketed as Mexoryl SX) is a photostable organic UVA filter used in sunscreens to protect skin from UVA-induced damage. It is water-soluble and often combined with other filters for broad-spectrum coverage.
| Reported effect | How often | Notes |
|---|---|---|
| Contact irritation (mild stinging, redness) | Uncommon | Generally mild and transient, particularly on sensitive or compromised skin. |
| Allergic contact dermatitis | Rare | Documented in isolated case reports; considered a low-sensitizing filter overall. |
| Photoallergic/photocontact reaction | Very rare | Occasional reports following sun exposure after application. |
| Eye irritation | Uncommon | Can occur if product migrates into the eyes, especially with sweating. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.