Salicylic Acid

What is it?

Salicylic acid is derived from willow bark, it belongs to a class of ingredients called salicylates. It’s structure is a little complicated, but understanding it is important to learning why (and how) it works so well.

When it comes to skincare products, there are two classes of acids you’ll see often: beta hydroxy acids (BHAs) and alpha hydroxy acids (AHAs). Salicylic acid is a beta hydroxy acid. This means the hydroxy part of the molecule is separated from the acid part by two carbon atoms, as opposed to an alpha hydroxy acid where they’re separated by one carbon atom.

Both alpha and beta hydroxy acids exfoliate the skin, but AHAs are water-soluble, while BHAs are oil-soluble. Generally, oil-soluble ingredients penetrate through the lipid layers between the skin cells more readily. In other words, oil-soluble ingredients can penetrate the skin at a deeper level than their water-soluble counterparts.

AHAs work well on the skin’s surface to loosen old, dead skin and reveal fresh newer skin. Salicylic acid works deeper and is able to penetrate into the pores to unclog them.

Benefits for your skin?

Salicylic acid can get deep into your skin to do its job. This quality is precisely what makes it such a potent ingredient for targeting acne — especially for blackheads and whiteheads.

Once it penetrates the skin, salicylic acid dissolves skin debris that clogs pores, acts as an anti-inflammatory, and also helps red, inflamed pimples and pustules go away faster.

The ingredient can penetrate so deeply into skin that actually breaks down the connections between skin cells. Once it has penetrated the skin, the acid part of the molecule can dissolve some of the intracellular ‘glue’ that holds skin cells together.

How to use in your skincare routine?

As with any exfoliant, it’s best to start slow if you have sensitive skin or are prone to irritation. Salicylic acid-based products are safe to use daily once the skin has acclimatised. If you have oily skin, you are more likely to be able to tolerate this quicker.

If your skin type is dry or sensitive, it’s more likely that salicylic acid could cause some irritation initially so a more gradual introduction may be required.