What it does
- Gently exfoliates and brightens the surface (as an AHA).
- Adjusts and buffers formula pH.
- Chelates trace metals, improving stability and antioxidant performance.
How it works
Citric acid is a multifunctional AHA. At higher levels and low pH it exfoliates; at low levels it is one of the most common pH adjusters and a mild chelator that protects formulas from metal-catalysed oxidation. As an AHA it can increase sun sensitivity when used for exfoliation.
Use level
- Typical use level
- exfoliating ~1–10%; low levels for pH/chelation
Around 1–10% for exfoliation at low pH; small amounts for pH adjustment and chelation.
Formulation considerations
- Water-soluble; low pH drives exfoliation.
- Widely used at low levels to set pH and chelate metals.
- Sun-sensitivity labelling applies when used as an exfoliant.
What it pairs with & what to avoid
Pairs well with
- Other AHAs and hydrators
- Antioxidant systems (as a chelator)
Use with care / avoid
- Skipping sunscreen when used to exfoliate
Regulatory status
Citric acid is listed in the EU CosIng database and is a long-established multifunctional ingredient.
Common questions
What does citric acid do in skincare?
It works as a gentle AHA exfoliant and, at low levels, as a pH adjuster and metal chelator that aids stability.
What percentage of citric acid is used?
Around 1–10% for exfoliation; much less for pH/chelation.
Does citric acid make skin sun-sensitive?
As an AHA it can, when used for exfoliation — use daily sunscreen.