The last two on the list are arguably the most common, but how much do you know about AHAs and BHAs—or which type is better suited for what skin type? Here, we provide all you need to know to make an informed choice. Of the AHAs, lactic acid and glycolic acid are often considered some of the most beneficial, as they’ve both been shown to1 increase skin cell turnover, improve moisture content of skin, and reduce the appearance of fine lines. They are also the most studied and researched, which is why you’ll find them in more skin care products. However, there are other forms, like malic and citric acids. Salicylic acid is a BHA, which is particularly beneficial for acne-prone skin3 due to its ability to unclog pores. “It is able to penetrate the skin deeper into pores to help remove dead skin cells, fight bacteria, and control excess sebum,” says board-certified dermatologist Zenovia Gabriel, M.D. As she notes, salicylic acid is also found to be antibacterial, making it particularly effective for acne-prone individuals, as it not only dissolves excess oil, but it targets the acne-causing bacteria building up in the pores. These exfoliating acids are also great at smoothing out the rough, bumpy skin associated with keratosis pilaris. Now, since these acids will be formulated with other ingredients, there’ll be some nuance to each and every product you try. For example, if an acid is buffered with calming ingredients like hyaluronic acid or squalane, it might not be as irritating to those with sensitive skin—even if it’s a “harsher” acid. And on the flip side, a more gentle, hydrating acid may be formulated at a higher concentration and bolstered with other powerful actives, making it stronger. Regardless, here are some general guidelines:
