Skincare ingredients can be confusing, especially when it comes to chemical exfoliants. AHA? BHA? PHA? What are they? What’s the difference? Is glycolic acid an AHA or a BHA?
Don’t worry, I’ve got you!
Here’s everything you need to know…
What Are Chemical Exfoliants?
Chemical exfoliants increase the rate that your skin naturally exfoliates itself. They do this by breaking down the bonds that hold your dead skin cells together which makes it easier for them to be shed from the surface of your skin.
There are three main types of chemical exfoliant; alpha-hydroxy acids (AHAs), beta-hydroxy acids (BHAs), and polyhydroxy acids (PHAs).
What Are AHAs?
AHAs are water-soluble acids made from sugars and fruits that help exfoliate your skin. They do this by removing calcium ions from the bonds that hold your skin cells together which weakens the bonds and enables exfoliation to take place.
AHAs are mainly used to treat:
- Sun damage
- Hyperpigmentation (e.g. dark marks, age spots, melasma, etc)
- Fine lines and wrinkles
- Enlarged pores
- Uneven skin tone
There are a wide variety of AHAs to suit every skin type.
What Are BHAs?
BHAs are oil-soluble acids that can penetrate deeper into your pores to exfoliate dead skin cells and oil. They can also help exfoliate the surface of your skin.
BHAs are mainly used to treat:
- Acne
- Oily skin
- Enlarged pores
- Fine lines and wrinkles
Is Glycolic Acid an AHA or BHA?
Glycolic acid is an AHA. In fact, it’s the most widely studied AHA and the most effective due to its low molecular weight. A low molecular weight means that a substance has small molecules that can penetrate your skin with more ease.
Other AHAs include:
- Lactic acid
- Malic acid
- Tartaric acid
- Mandelic acid
- Citric acid
Although acids with smaller molecules are more effective, they’re also more likely to cause skin irritation. The larger the molecule, the slower it penetrates your skin and the less likely it is to cause irritation.
How To Use Glycolic Acid and Other AHAs
Glycolic acid should only be used 1-3x per week unless it’s in a cleanser or a multi-ingredient product intended for daily use (as they’re usually tested for irritation potential).
Using glycolic acid too frequently can cause skin barrier damage which can leave your skin feeling dry and irritated, as well as making a number of skin conditions worse.
Glycolic acid should always be applied to dry skin as damp skin is more permeable (things can go in and out easier) which means an increased risk of irritation.
If you’re using glycolic acid or other AHAs then you need to be extra vigilant with your sun protection as these exfoliants increase your skin’s sensitivity to the sun.
Choosing the right acid for your skin type is mainly down to personal preference but here are some examples of acids that work particularly well for a specific skin type:
- Normal skin – glycolic acid
- Oily skin – salicylic acid
- Combination skin – mandelic acid
- Dry skin – lactic acid
- Sensitive skin – malic acid
Pairing acids with hydrating ingredients like hyaluronic acid and ceramides or ingredients that increase your skin’s natural production of these ingredients (e.g. n-acetyl glucosamine, glucuronic acid, niacinamide) can help keep your skin barrier strong and prevent irritation.
Summary – Is Glycolic Acid an AHA?
Yes, glycolic acid is an AHA and a very effective chemical exfoliant. It has a wide range of benefits for your skin but may initially cause some irritation. If you have sensitive skin, you may find that other AHAs are a better option for you and if you have particularly oily skin then salicylic acid may be the best choice of chemical exfoliant for you.
