Hydroquinone
What it is
A potent skin-lightening agent that is considered the gold standard for treating hyperpigmentation, such as melasma and post-inflammatory hyperpigmentation.
How it works
Hydroquinone works by inhibiting tyrosinase, the enzyme necessary for melanin production. This action decreases the production of melanin, leading to a gradual lightening of the skin.
Benefits
- Highly effective at fading dark spots and hyperpigmentation.
- Considered the gold standard for treating melasma.
Formulation notes
Effective concentration: 2% (OTC) to 4%+ (Prescription).
pH range: 3.0 - 5.5
Stability: Highly unstable; oxidizes quickly when exposed to air and light, turning brown.
Safety
Irritancy: Moderate to high, can cause redness and dryness.
Comedogenicity: 0
Warnings: Controversial ingredient; banned in some countries for cosmetic use. Can cause ochronosis (a bluish-black discoloration) with long-term, high-concentration use. Use should be supervised by a dermatologist.
Ratings
Paula's Choice: Best
INCIdecoder: goodie