7 types of acids in skincare and how to choose the correct one?

I feel like there isn’t a woman that doesn’t use some sort of an active ingredient in skincare, especially acids. But, do you know what is the best acid for your skin type and how to use it?

Classification of acids in skincare

There are many different types of acids in skincare, but we can divide them into 3 main groups, based on their primary function:

1. AHA – an alpha-hydroxy acid
2. BHA – beta-hydroxy acid
3. PHA – poly-hydroxy acid

AHAs (alpha-hydroxy acids in skincare)

AHAs are a group of acids derived from fruits, milk, nuts or sugar. We can use them in a variety of anti-ageing products in form of serums, toners and creams. Alternatively, we can use them as treatment called a chemical peel..

Overall, alpha-hydroxy acids main purpose is to exfoliate.

Along with exfoliation, AHAs can also help with:

• reducing the appearance of wrinkles
• reducing hyperpigmentation
• brightening the complexion
• prevent acne breakouts
• reducing the appearance of scars

6 most often used types of alpha-hydroxy acids in skincare are:

1. glycolic acid – derived from sugar, the best option for oily skin, helps regulate sebum production
2. malic acid – derived from apples, it’s hydrating and calming
3. tartaric acid – derived from grapes, an excellent antioxidant
4. citric acid – derived from citrus fruits and corns, brighter complexion, increases skin density, anti-ageing
5. lactic acid – derived from milk and other carbohydrates, helps with hyperpigmentation, antimicrobic, regulates the pH of the skin
6. mandelic acid – derived from bitter almonds, helps with hyperpigmentation and acne

Importantly, we should note that people with very sensitive skin and rosacea should not use alpha-hydroxy acids.

BHAs (beta-hydroxy acids)

Besides AHAs, BHAs are also a group of acids. But, in skincare, we predominantly use salicylic acid. Salicylic acid naturally occurs in white willow tree bark, sweet birch and evergreen trees oils. Just as with AHAs, the main purpose of BHAs is also to exfoliate.

Except for exfoliation, BHAs can also help with:

• cleaning the pores (dissolving the oils in pores)
• fighting inflammation
• soothing the redness
• fighting acne and breakouts

Concentrations of beta-hydroxy acids in skincare can range between 0.5% and 5% depending on the product. Generally, we should start with the lowest concentration using it only once or twice a week and work your way up.

PHAs (poly-hydroxy acids)

PHAs are also a group of acids that are a great alternative to AHAs. Not only that they have the same effect as AHAs, but also they have much fewer side-effects. Hence, PHAs being the perfect choice for sensitive skins. This is because they have a larger molecular structure than AHAs so they penetrate the skin much slower. Because of that, poly-hydroxy acids exfoliate the skin much slower and cause less irritation on sensitive skins.

Poly-hydroxy acids:

• exfoliate the skin and increase cell renewal
• are anti-inflammatory
• work as an antioxidant
• lock in the moisture

Most often used poly-hydroxy acids in skincare are:

1. lactobionic acid – it’s an oxidized form of lactose, derived from milk, soothing for the skin, exfoliates, antioxidant and anti-ageing
2. gluconolactone – exfoliates, anti-ageing

Which acid to choose?

Choosing the correct acid for your skin type is the hardest part. There is so many available, and every day there is another article saying how you need that exact acid to have the perfect skin.

In short, the easiest way to determine which acid is the best for you is to know which problem you want to treat. Also, you need to be aware of your skin type, not just the condition. As well as that, you need to understand if your skin is dry or dehydrated because they’re not the same thing. In case you need a reminder, I wrote about the difference here.

With this in mind, I made a table you can use for reference.

Are you using any acid in your skincare routine? Have you found the perfect one?