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Ingredient

Lactic Acid

An alpha hydroxy acid that exfoliates and also acts as a humectant, so it is often chosen as a gentler option.

  • CAS 50-21-5

What it is there to do

  • Exfoliant

    Loosens or dissolves the bonds between surface skin cells.

  • Humectant

    Draws water into the upper layers of the skin or hair.

Where this comes up

The notes BeautySignal puts beside this ingredient when it is on a label.

  • Contains exfoliating acids

    This product contains an exfoliating acid. These work by loosening the bonds between surface skin cells, and are usually introduced gradually.

    Why we mention it

    Concentration and pH change the effect substantially, and neither is usually disclosed, so an absolute statement would be misleading.

What we don't know

  • Where it comes from — plant, mineral, synthetic — isn't recorded.
  • No published rule in our reference names it. That is about the rules, not safety.
  • How much of it is used in any particular product. We hold no concentrations at all.

This is information about an ingredient, not medical advice, and not a judgement about any product that contains it. Back to the reference.