Kojic Acid.

What it does

Benefits

• Fades hyperpigmentation, melasma, and post-acne dark marks by blocking melanin formation
• Evens out overall skin tone and helps with sun-induced discoloration
• Naturally fermentation-derived alternative to harsher lightening agents
• Has mild antioxidant and antimicrobial properties

Side effects

• Can cause contact dermatitis, redness, or sensitization, especially at higher concentrations or with prolonged use
• Chemically unstable and prone to oxidizing (turning brown) when exposed to air and light, which can reduce effectiveness
• May increase sensitivity, so daily sunscreen is recommended to keep treated spots from re-darkening

Who it's for

People with melasma, sun spots, or post-inflammatory hyperpigmentation looking for a gentler, fermentation-derived brightener

Who should be careful

Those with very sensitive or reactive skin or a known kojic acid allergy; patch-test first, since prolonged use is associated with contact dermatitis and sensitization. Use under medical guidance if pregnant or breastfeeding.