Antioxidants are a broad class of ingredients (e.g., vitamin C, vitamin E, ferulic acid, niacinamide, polyphenols) that neutralize reactive oxygen species generated by UV exposure and pollution. They are used to reduce oxidative damage, support photoprotection, and address signs of aging and uneven tone.
| Reported effect | How often | Notes |
|---|---|---|
| Mild transient stinging or irritation | Common | Most often with low-pH formulations such as L-ascorbic acid, especially on sensitive or compromised skin. |
| Erythema (redness) | Uncommon | Can occur with higher concentrations or when combined with other actives. |
| Allergic or irritant contact dermatitis | Rare | Reported with certain antioxidants and their preservatives or vehicle components. |
| Paradoxical yellow-orange skin staining | Rare | Associated with oxidized/degraded vitamin C products. |
| Photosensitivity-like reactions | Very rare | Isolated reports; most topical antioxidants are not considered photosensitizing. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.