What is Citric Acid?
Citric Acid is an alpha hydroxy acid (AHA) found naturally in citrus fruits such as lemons, limes and oranges. The citric acid used in skincare is typically made by fermenting sugars rather than squeezed from fruit.
In most products, citric acid is not the star exfoliant. It is mainly used in small amounts to adjust a formula's pH, which keeps the product stable and skin-friendly. It can also exfoliate, but that needs the right formula and a strength that most products do not reach.
Source
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Found in |
Citric Acid (INCI name) |
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Origin |
Occurs naturally in citrus fruits; cosmetic grade is typically produced by fermentation |
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Also known as |
AHA, fruit acid |
Top features and benefits
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Adjusts and balances product pH |
Helps keep formulas stable |
Can gently exfoliate at the right strength |
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Part of the AHA family |
Widely used in cleansers, toners and serums |
Often supports other acids in a blend |
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Natural fruit-acid origin |
Low-cost, well-known ingredient |
Usually present at low levels |
How Does It Work?
Most of the time, citric acid works behind the scenes. Many skincare ingredients only behave properly within a certain pH range, and citric acid is a simple way for formulators to bring a product to that range. If you see it near the end of an ingredient list, it is most likely doing this job.
As an exfoliating AHA, citric acid loosens the bonds between dead skin cells so they shed more easily. However, the research on this effect has used much higher strengths, around 20 percent, than most skincare products contain, so a typical product with citric acid in it is unlikely to be a strong exfoliant.
Glycolic and lactic acid are better studied for exfoliation and are less likely to sting, so they are usually the first choice when exfoliation is the goal. Citric acid is better thought of as a supporting ingredient that helps the whole formula work.