Our essential guide to skincare acids

If you are experiencing breakouts then don’t panic - there are plenty of amazing skincare ingredients out there that will help to tackle spots and blemishes. Right at the very top of the list are skincare acids; absolute must-have skincare actives to include in your routine if you have blemish prone skin.

What are skincare acids?

Skincare acids can be found in loads of different products (anything from a cleanser to an overnight cream), and are mainly used as chemical exfoliants to loosen the bonds between skin cells. This helps to shift dead cells from the skins surface, which makes many acids go-to ingredients for not only brightening skin, but also for getting rid of unwanted dirt, oil and skin debris that can clog pores and lead to breakouts.

However, there are quite a few skincare acids out there and some will suit skin prone to sensitivity, while others are more potent to give a more intense result. They also have a range of different skincare benefits, so here’s our need-to-know essential guide:

AHAs vs BHAs

Most skincare acids are classed as either alpha hydroxy acids (AHAs) or beta hydroxy acids (BHAs).

  • AHAs are water soluble and work mainly on the skin surface, so are generally used to deliver brighter, more radiant skin.

  • BHAs are oil soluble and so can penetrate more deeply into skin and bind themselves to sebum, so are great for unclogging pores (which we why we love a BHA as they are brilliant at helping to clear congested skin! 💛).

So now you know your AHAs from your BHAS, here’s the headlines for the most common acids you can add into your skincare regime:

  • Glycolic Acid: A small molecule AHA which can penetrate more deeply than other AHAs, so it can help to stimulate collagen production to tackle lines and wrinkles as well as helping to brighten and even out skin tone. The downside is that it can cause irritation if used in high levels so you may need to build up tolerance when first using it.

  • Lactic Acid: A larger molecule AHA which means it can’t penetrate as deeply as Glycolic. Although the results from using Lactic vs Glycolic might not be as dramatic, the benefit of using a larger molecule size like Lactic Acid is that people who have more sensitive skin might tolerate it better. Add it into your routine to brighten skin, improve skin texture and reduce the signs of pigmentation. Bonus - it also helps to draw moisture to the skin so can help skin prone to dryness too.

  • Malic Acid: Derived from apples, Malic Acid is increasing in popularity because of its large molecule size, making it super gentle. Like Lactic, it also helps to draw moisture to the skin. So although Malic might not pack as much of a punch as Latic or Glycolic, it’s again good for those with sensitive skin. It also can help to reduce the production of melanin, helping to prevent hyperpigmentation.

  • Mandelic Acid: Derived from bitter almonds, Mandelic Acid helps to brighten and even skin tone in line with other AHAs. However, it’s also useful to fight blemishes by helping to control excess sebum production. It’s larger molecule size also means its gentler than some other AHAs.


There is really only one BHA that is commonly used in skincare:

  • Salicylic Acid: An absolute hero ingredient for helping to fight blemishes (you might have noticed it’s in quite a few of our Clear Skin Days products!). It is often recommended by experts to help treat mild acne, and it works by penetrating skin to help dissolve the debris that can clog up pores, as well as acting as an anti-inflammatory to calm blemishes. Basically, its a must-have ingredient for tackling acne and oily skin.

So now you know the basics for the most common AHAs and BHAs, there are a few other skin acids that are worth considering adding to your skincare routine:


Polyhydroxy acids (PHAs) are less well known than AHAs and BHAs, but are a group of acids regarded as a more gentle option to an AHA or BHA. Probably the best known of these is Gluconolactone, which has a very large molecule size so it still exfoliates and brightens skin but is less irritating than more potent acids. It is also a humectant so helps to keep skin moisturised.

Hyaluronic Acid

Hyaluronic Acid works completely differently to AHAs / BHAs and PHAs, so the name is a bit of a decoy. HA is found naturally in the body as a sugar, and holds water to keep moisture in our skin and joints. You will spot HA in pretty much any hydrating skincare product out there, and it works by drawing in moisture to skin to keep skin plumped and dewy. Basically, it’s not a chemical exfoliator like the rest of the acids mentioned above, but we thought it was mentioning in case of the name confusion. Plus it’s a total powerhouse of a skincare ingredient so we love to talk about HA whenever we get the chance :)

How should I use skincare acids?

So now that you know your Mandelic from your Salicylic, how should you start introducing acids into your skincare routine? For Hyaluronic Acid, this can be introduced anytime as its sole purpose is to hydrate your skin. For exfoliating acids (AHAs, BHAs and PHAs), if you are new to acids and your skin is prone to sensitivity, then you should ideally introduce an acid gradually into your routine a couple of times a week. To be safe, always check the “how to use” on the packaging label to provide the right guidance on how many times a week you should use the product. And lastly, we hate to nag but please remember to always wear sunscreen!


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