What does tyrosinase do?
Tyrosinase is the key enzyme melanocytes use to convert the amino acid tyrosine into melanin, through a multi-step chemical process. It is the rate-limiting step of melanin production — meaning if tyrosinase activity is reduced, melanin production slows down correspondingly. This makes tyrosinase the primary target for almost every brightening and depigmenting ingredient in modern skincare.
A tyrosinase inhibitor works by binding to or interfering with this enzyme, reducing the rate at which melanocytes can manufacture new pigment. Importantly, this addresses future pigment production — it does not immediately remove pigment that has already formed, which is why tyrosinase inhibitors are always combined with exfoliating or peeling treatments for existing dark patches.
Common tyrosinase inhibitors
Azelaic acid: a well-tolerated, naturally derived acid effective at inhibiting tyrosinase while also having anti-inflammatory and antibacterial properties, making it useful for pigmentation linked to acne. Kojic acid: derived from fungi, one of the more potent tyrosinase inhibitors, though it can be irritating at higher concentrations for sensitive skin.
Tranexamic acid: originally a medical treatment to reduce bleeding, now used topically for melasma specifically — targeting a blood-vessel-related inflammatory pathway linked to UV-triggered pigmentation, not tyrosinase directly. Niacinamide (vitamin B3): a gentle, well-tolerated option that also reduces the transfer of melanin from melanocytes to surrounding skin cells. Vitamin C: an antioxidant that inhibits tyrosinase and also has independent brightening effects.
Why tyrosinase inhibitors are only part of the picture
No tyrosinase inhibitor works effectively without daily SPF. Since UV exposure is the primary trigger for tyrosinase activation, using a brightening product without consistent sun protection means new melanin production continues to outpace the treatment. This is why every pigmentation protocol at Star Aesthetic Centre pairs a tyrosinase-inhibiting home-care routine with mandatory daily Heliocare 360° SPF 50+.