What Is Citric Acid?

Citric acid contains alpha hydroxy acid (AHA). AHAs are a common component used by both skincare enthusiasts and dermatologists to help enhance the texture and general look of the skin.

Citric acid is a weak acid that is present in both plants and animals, especially citrus fruits, and is responsible for the acidic flavour of these fruits. Lemon juice, for example, contains around 5 to 8 percent citric acid. Over a million tonnes of citric acid are generated per year. This product has a variety of applications, including being an acidifier, a flavouring, and a skincare ingredient. 

Citric acid is also widely used in cosmetics and personal care products. Citric acid was used in almost every type of cosmetic product, according to the 2016 Voluntary Cosmetic Registration Program of the United States Food and Drug Administration, with over 10,000 registered uses. It is important to note, however, that these materials are designed by chemists with sensitivity and protection in mind. To reap the advantages of citric acid, it is often safest to use a product that contains citric acid, as lemon juice on its own is too acidic for the skin.

How Citric Acid Works?

In skincare and cosmetic formulations, citric acid acts as an alpha-hydroxy acid, or AHA. AHAs are a kind of chemical compound that consists of a carboxylic acid (-COOH) substituted on the adjacent carbon with a hydroxyl group (-OH). AHAs can be extracted directly from berries, such as citric acid from citrus fruits, or they can be synthesised.

AHAs are well known in the skincare industry for their use in reducing symptoms of ageing such as wrinkles, lines, and pigmentation. AHAs are also commonly used for their ability to stimulate collagen formation. According to a report conducted in the Journal of Dermatologic Surgery, AHA treatments increase collagen production and the proliferation of fibroblast, which results in a reduction in fine lines and wrinkles. 

What Citric Acid Does To The Skin?

Citric acid improves the texture and appearance of the skin by gently exfoliating it and promoting skin cell turnover.

When used properly, citric acid therapies can help brighten skin, lessen the presence of pores, promote the healing of mild acne, diminish the visible colour associated with dark spots, and enhance the appearance of fine lines. Citric acid exfoliates the top layers of skin and sloughs off dead skin cells as added to the skin. Furthermore, the rate of new cell turnover increases, promoting new skin development and helping to reduce the presence of age marks, acne lesions, small lines, and regions of irregular tone and texture.

Reference Sources

  • Fiume, M et al., 2014. ‘Safety Assessment of Citric Acid, Inorganic Citrate Salts, and Alkyl Citrate Esters as Used in Cosmetics’, International Journal of Toxiciology.
  • Bernstein, E, et al., 1997. ‘Citric Acid Increases Viable Epidermal Thickness and Glycosaminoglycan Content of Sundamaged Skin, Dermatologic Surgery, vol. 23, is. 8, pp. 689-694.
  • Babilas, P, Knie, U & Abels, C, 2012. ‘Cosmetic and dermatologic use of alpha hydroxy acids’, Journal of the German Society of Dermatology, vol. 10, is. 7, pp. 488-491.