6 Acids with Brightening Superpowers

Acids are powerhouse ingredients essential for healthy, glowing skin. Their exfoliating activity triggers the epidermis into remodel mode, reducing the appearance of fine lines, smoothing texture, and clearing away dull, dead cells to reveal a fresher, brighter appearance. While all acids contribute to surface-level brightening, some excel at addressing excess pigment and promoting even tone from the cells up. Meet the elite: six must-know acids with unique abilities to reveal your skin's luminous potential.

Mandelic acid enhances brightness in two ways. It inhibits the melanin-producing enzyme tyrosinase to block pigment from forming and helps lift surface pigment through exfoliation. Its large molecular structure slows absorption into the skin, making it the gentlest of the AHAs. It also has antibacterial and anti-inflammatory properties to fight acne. Mandelic acid is a particularly good choice for skin of color or sensitive types because of its non-irritating activity.

Kojic acid is a natural skin brightening compound derived from mushrooms. It works by blocking the production of tyrosinase, the enzyme responsible for melanin synthesis. It also helps exfoliate surface pigment and stimulate cell renewal while providing antioxidant protection from photodamage.

Like glycolic acid, its sugar-derived cousin, lactic acid acts directly on melanocytes to inhibit tyrosinase and reduce excess pigment. However, large-molecule lactic acid penetrates less deeply and at a slower rate, placing it among the gentlest of the AHAs. A powerful humectant, lactic acid is an excellent choice for those with dry, sensitive, or reactive skin, or those new to acids in skincare. 

This antioxidant powerhouse interacts with copper to inhibit the melanin-stimulating enzyme tyrosinase, reducing the formation of pigment and encouraging a brighter, more even tone. It also has a potent photoprotective effect, especially when combined with vitamin E, to reduce melanin triggers. As an essential component in collagen synthesis, vitamin C supports a firmer skin structure.

While not technically an acid, vitamin A is converted into retinoic acid in the body, where its potent antioxidant properties get to work. It disrupts the oxidative process induced by environmental stressors to prevent and repair cellular damage, including dark spots. Retinols also brighten skin by accelerating cell turnover, to disperse surface-level pigmentation. As a bonus, this cell signaling agent boosts collagen production to thicken and firm the skin. Retinols are often used in combination with other AHA brighteners to maximize results.