Biotin (vitamin B7) is a water-soluble vitamin used in topical formulations as a conditioning agent, though evidence for meaningful benefit to skin, hair, or nails when applied topically is limited. It is more commonly associated with oral supplementation claims for hair and nail health.
| Reported effect | How often | Notes |
|---|---|---|
| Skin irritation or redness at application site | Rare | Topical biotin is generally well tolerated; mild local irritation may occur in sensitive individuals. |
| Allergic contact dermatitis | Very rare | Sensitization to biotin in topical products is uncommon but reported. |
| Interference with laboratory test results | Uncommon | Primarily linked to high-dose oral intake rather than topical use; can skew certain immunoassays. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.