Superoxide Dismutase

Superoxide dismutase is an antioxidant enzyme used in low topical concentrations (typically fractions of a percent) to help reduce oxidative stress, and it is generally well-tolerated in clinical and cosmetic use with low rates of irritant reactions. However, as a bio-derived protein (often from yeast/bacterial sources) it can occasionally trigger stinging or hypersensitivity in highly reactive or barrier-impaired skin, so it is not truly inert. In sensitive populations, the main risk is rare delayed sensitization or reactions to the delivery system rather than intrinsic irritancy, supporting a very gentle score. Safety Notes: In commercial skincare, Superoxide Dismutase (SOD) is most often used as a low-dose antioxidant/soothing active in leave-on serums and creams, commonly in the 0.001–0.02% range, with the lowest observed levels (~0.0001%) appearing when it is part of multi-enzyme or fermented/botanical complexes. High-strength consumer-available antioxidant serums and ampoules (non-prescription) have been marketed up to ~0.05–0.10% SOD (typically via stabilized SOD actives or encapsulated forms), with stability and cost usually preventing meaningfully higher true SOD loadings in OTC products; rinse-off products tend to sit at the low end due to short contact time.