Ingredients

Citric Acid

Written by Reviewed by the SYNC editorial team Published Last reviewed Editorial standards

Citric Acid — an alpha hydroxy acid derived from citrus fruits that provides light exfoliation and is also widely used to adjust and stabilize the pH of skincare formulas. In addition to smoothing the skin surface, it functions as a chelating agent and antioxidant helper in many products. It appears across a broad range of formulations, often in a supporting role.

Key points

  • Citric acid is an AHA that offers mild exfoliation while brightening the look of the skin.
  • It is very commonly used as a pH adjuster, helping bring acidic products to their target range.
  • It can act as a chelating agent, binding trace metals that might otherwise affect product stability.
  • At low levels it serves a formulation function, while higher levels contribute more to exfoliation.
  • Because it is an AHA, using sunscreen during regular use is advised.

Frequently asked

Is citric acid mainly an exfoliant or a formulation ingredient?

It plays both roles, offering gentle exfoliation at higher concentrations while very often being used in small amounts to adjust a product's pH. Its function depends on how much is included and the product type.

Can citric acid irritate the skin?

At the low levels used for pH adjustment it is usually non-irritating, but higher exfoliating concentrations can cause stinging or sensitivity in some people. Patch testing helps you assess tolerance.

Related topics

This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.

Encyclopedia

Further reading

This entry was written and checked against the sources below. They are published by clinical and scientific bodies, they are listed most readable first, and each one opens in a new tab. They are background for the whole entry rather than footnotes to individual sentences.

  1. Chemical peels (face peels) DermNet NZ Clinical guidance dermnetnz.org
  2. Cosmetics Alpha Hydroxy Acids U.S. FDA Regulatory and safety fda.gov
  3. Guidance for Industry: Labeling for Cosmetics Containing Alpha Hydroxy Acids U.S. FDA Regulatory and safety fda.gov
  4. Evaluating the Efficacy and Safety of Alpha-Hydroxy Acids in Dermatological Practice: A Comprehensive Clinical and Legal Review PubMed Central Peer-reviewed, open access pmc.ncbi.nlm.nih.gov
  5. Cosmetic and dermatologic use of alpha hydroxy acids PubMed Peer-reviewed (abstract) pubmed.ncbi.nlm.nih.gov
  6. Evaluating the Efficacy and Safety of Alpha-Hydroxy Acids in Dermatological Practice: A Comprehensive Clinical and Legal Review PubMed Peer-reviewed (abstract) pubmed.ncbi.nlm.nih.gov

SYNC does not publish medical advice. Nothing here replaces a consultation with a doctor or a pharmacist about your own skin.