7-Dehydrocholesterol is a cholesterol derivative naturally present in skin that converts to vitamin D3 upon UVB exposure. In skincare it functions as a barrier-supporting lipid precursor and provitamin antioxidant.
| Reported effect | How often | Notes |
|---|---|---|
| Mild skin irritation or redness | Rare | Possible in sensitive individuals, generally well tolerated topically |
| Contact dermatitis or allergic reaction | Very rare | Isolated sensitization reports; not commonly documented |
| Photosensitivity-related changes | Very rare | Compound is UVB-reactive, but adverse photoreactions in cosmetic use are seldom reported |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.