4-Butyl Resorcinol is a resorcinol-derivative active used topically to reduce hyperpigmentation by inhibiting tyrosinase, the key enzyme in melanin synthesis. It is studied for treating melasma, age spots, and uneven skin tone.
| Reported effect | How often | Notes |
|---|---|---|
| Mild skin irritation (redness, stinging, burning) | Common | Typically transient and dose-dependent, occurring early in use. |
| Dryness or scaling | Uncommon | More likely with higher concentrations or sensitive skin. |
| Contact dermatitis / allergic sensitization | Rare | Patch testing advised in individuals with sensitive or reactive skin. |
| Paradoxical post-inflammatory hyperpigmentation | Rare | May follow irritation, particularly in darker skin phototypes. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.