4-n-Butylresorcinol is a resorcinol derivative used in topical cosmetics to reduce hyperpigmentation by inhibiting tyrosinase and tyrosinase-related protein-1, key enzymes in melanin synthesis. It is commonly applied to treat melasma and age-related dark spots.
| Reported effect | How often | Notes |
|---|---|---|
| Mild skin irritation (stinging, burning) | Common | Transient sensation often noted at higher concentrations or on sensitive skin. |
| Erythema (redness) | Uncommon | Localized redness at application site, usually resolving with continued use or reduced frequency. |
| Contact dermatitis / allergic sensitization | Rare | Reported in patch-test studies; resorcinol derivatives carry some sensitization potential. |
| Dryness or scaling | Uncommon | Mild peeling may occur, particularly when combined with other actives. |
| Post-inflammatory hyperpigmentation | Rare | Paradoxical darkening if significant irritation occurs, especially in darker skin types. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.