Lactic acid is an alpha hydroxy acid (AHA) derived from milk, fruits, and vegetables, widely used in skincare for its gentle exfoliating, hydrating, and brightening properties. As a water-soluble acid, it works by breaking down the bonds between dead skin cells, allowing them to shed more easily and revealing smoother, more radiant skin underneath. Unlike some other AHAs, lactic acid is known for its humectant properties, meaning it attracts and retains moisture, making it an excellent choice for individuals with dry or sensitive skin.

One of lactic acid’s biggest benefits is its ability to improve skin texture and tone while minimizing the appearance of fine lines, dullness, and hyperpigmentation. It stimulates cell turnover and collagen production, which helps promote firmer, plumper skin over time. This makes it a popular ingredient in anti-aging treatments, chemical peels, and brightening serums. Because lactic acid molecules are larger than those of glycolic acid, they penetrate the skin more slowly, making it a milder and less irritating option for exfoliation.

Lactic acid is often used in concentrations ranging from 5% to 10% in over-the-counter products, such as cleansers, toners, masks, and serums. Higher concentrations, typically above 10%, are found in professional-grade chemical peels. Regular use can help fade sun spots, post-inflammatory hyperpigmentation (PIH), and melasma, making it a go-to ingredient for those dealing with uneven skin tone.

Despite its gentle nature, lactic acid can increase sun sensitivity, so using sunscreen daily is essential when incorporating it into a skincare routine. It pairs well with hydrating ingredients like hyaluronic acid and soothing agents like niacinamide to counteract any potential irritation. Whether used as a mild daily exfoliant or in a stronger treatment, lactic acid is a highly effective ingredient for achieving softer, smoother, and more radiant skin.