Social media has put kojic acid in the spotlight, with viral soaps and serums claiming the ingredient can fade hyperpigmentation and even out skin tone. E! News spoke with Patricia Heredia, a master aesthetician at SkinSpirit Nordstrom NYC, about what the ingredient actually does.
Heredia described kojic acid as a naturally derived brightening ingredient made through the fermentation of certain fungi. According to her, it helps reduce the look of discoloration by slowing tyrosinase, the enzyme involved in producing melanin.
She said kojic acid and vitamin C can both help brighten skin, but they work differently. Vitamin C acts as an antioxidant that helps protect skin from damage caused by UV exposure and pollution, while kojic acid specifically targets pigment formation.
Heredia said kojic acid is most useful for evening out skin tone and can be helpful for post-acne discoloration, dark marks from ingrown hairs, sunspots, and some forms of melasma. She also noted that it does not bleach the skin; instead, it helps regulate excess pigment while supporting the fading of existing spots.
She added that sunscreen is essential when using kojic acid, and people with very sensitive skin, active eczema, or a weakened skin barrier should be cautious because it may cause irritation. She also advised against layering too many active ingredients at once, saying that overdoing it can damage the skin barrier and potentially worsen inflammation and pigmentation.
