The multiple benefits of acids have made chemical exfoliants very popular.
What affects how well they perform? The type of acid? The concentration?
The answer is "Yes" to both of the above, but there is more to it.
Types of acids
There are 2 types of acids, AHAs (alpha-hydroxy acids) and BHA (beta-hydroxy acid). Both exfoliate by loosening the skin layers, though each are better in different aspects.
AHAs (up to 15%)
- water soluble
- increase moisture levels in the skin as they are also humectants
- suitable for all skin types especially dry; best for dullness, hyperpigmentation, evening out skin tone
- smaller the molecular size, stronger the exfoliation smallest = glycolic acid; largest = lactobionic acid
- e.g. glycolic, lactic, malic, tartaric, mandelic, lactobionic acids
- oil-soluble; can enter pores removing clogs/sebum within
- anti-inflammatory, anti-bacterial
- suitable for normal to oily skins; best for congestion/blemishes
- only 1 BHA used in cosmetics - salicylic acid
BHA (up to 2%)
The type and amount of acid are only half the story. There are other things that affect the exfoliant's effectiveness.
- pH of product
Should be within pH 3 to 4. Any lower is too irritating; any higher makes the acid lose its exfoliating property.
- Length of contact time
Leave-on products give acids more time to work compared to masks or cleansers.
- Accompanying irritants
Low pH amplifies the irritancy potential of other irritants also present. Ingredients to avoid are alcohol, fragrance (including essential oils), imidazolidinyl urea and isothiazolinones.
- Inherent skin condition of user
The same product can feel/have different effects on different individuals. Someone with a thick outermost skin layer will be less sensitive to temporary tingling, redness or peeling.
The Perfect Exfoliant
There is a lot to think about when formulating a chemical exfoliant - too strong gives you uncomfortable side effects; and too mild wouldn't deliver the benefits.
A successful formula delicately balances effectiveness and level of 'irritation' for your skin. You can hunt around for the right one, or let us custom formulate your perfect exfoliant for maximum performance minus any irritation.