All products are selected by our editors independently. We may earn affiliate commissions if you buy something.
        Glycolic acid instantly brightens skin, while azelaic acid adds to its list of acclaimed acne-fighting properties. But what about citric acid?
       While it sounds like this summer’s new nail polish shade, citric acid is actually an alpha hydroxy acid (AHA) – and if you have oily skin or clover-leaf-like hyperpigmentation, citric acid comes in handy on your cheeks and forehead.
        Paula Begun, founder of Paula’s Choice skincare, explains that one reason citric acid is less well known is because there has been more research done on its cousins, glycolic and lactic acids. But this in no way diminishes its ability to gently exfoliate dead skin cells, unclog pores, or improve overall skin clarity.
        In nature, citric acid gives lemons and limes their sour bitter taste. In skincare formulations, it’s used to balance the pH of products so they’re not too alkaline, according to Begun.
        Citric acid is classified as an alpha hydroxy acid (AHA). “This is a powerful exfoliator that removes the top layer of dead and dying skin cells for a smoother, more even complexion,” says associate physician and cosmetologist Dr. Kemi Fabusiva. “It inhibits excess melanin production and also helps reduce hyperpigmentation.”
        As an exfoliator: Citric acid is an effective chemical exfoliator in both home products and clinical treatments. Like all AHAs, it dissolves the jelly-like bonds that hold dead cells to the surface of the skin. But unlike glycolic acid, it’s made up of large molecules that don’t easily penetrate the skin. So while citric acid is a weaker exfoliator, it is better tolerated than many other AHAs. “Studies have shown that the effectiveness of citric acid also depends on how long it stays on the skin,” says Dr. Adil Sheraz, Consultant Medical and Dermatological Surgeon. “So if you leave it on as an exfoliator for a few minutes, you can look forward to smoother skin and a more radiant look.”
       Improves skin firmness: Because citric acid speeds up skin cell turnover, it can help boost collagen production, “which can help firm skin by providing structure and support to the epidermis,” says Dr. Fabusiva.
        Kills acne-causing bacteria: “Citric acid is known to have antimicrobial properties,” explains Dr. Fabusiva. “Combined with other ingredients to help reduce oiliness, citric acid has been shown to be an effective acne-fighting ingredient.”
       Antioxidant: Antioxidants protect against environmental damage caused by pollution and UV rays, which have been shown to cause hyperpigmentation.
       Dr. Fabusiva notes that, as with all skin care products, the frequency of application depends on the concentration of citric acid as well as the type of product.
       ”In general, low concentrations in mild formulas can be used daily, while more concentrated serums should only be used once or twice a week,” she says, adding that you should use package instructions as a guide while pay attention to how it feels on the skin, and reduce use if there are signs of inflammation.
        The good news is that if you’re already using vitamin C or hyaluronic acid serums, citric acid is a great addition. As a skin brightener and antioxidant, vitamin C works synergistically with citric acid to improve the appearance of hyperpigmentation and protect against environmental aggressors.
        At the same time, “hyaluronic acid works great with all the ingredients,” says Dr. Fabusiva. “Hyaluronic acid hydrates the skin by drawing moisture from the environment and also helps to reduce any irritation or sensitivity caused by citric acid.”
        “Citric acid is often paired with beta-hydroxy acids (BHAs) like salicylic acid,” says Dr. Sheraz. “However, if you have sensitive skin, start slowly and gradually increase the amount you use. If you use retinoids, then again I would recommend caution: use citric acid during the day and retinoids at night.”
       When it comes to exfoliation, the usual rules apply: If you’re already using a chemical exfoliator, don’t double up on a physical facial scrub, as this can cause inflammation.
        According to Dr. Sheraz, citric acid is generally well tolerated because it is on the weak end of the spectrum. “However, any acid can cause irritation, especially if you have sensitive skin or a condition like rosacea,” he warns. So before using it on your face, do a patch test by applying a little on the inside of your forearm and stop using if irritation occurs.
       ”Citric acid also makes you more susceptible to the sun’s UVB and UVA rays, so using sunscreen is critical,” he adds.