Salicylic Acid and Acne – Everything You Need to Know
With up to 85% of Australians experiencing acne in their lifetime1, salicylic acid is a skincare ingredient worth getting to know. Able to penetrate pores to remove built-up skin cells, it’s a common ingredient in many acne skincare products. But what IS salicylic acid, exactly? And what do you really know about the relationship between salicylic acid and acne?
To help you on your path to clearer skin, we’ve created a go-to guide to this anti-acne acid. From the benefits of salicylic acid to its potential side effects and role in controlling breakouts, here’s everything you need to know. Read on!
What is Salicylic Acid?
Glycolic acid, lactic acid and salicylic acid are all chemical compounds known as hydroxy acids. While closely related, the first two are part of the alpha hydroxy acid (AHA) family, whereas salicylic acid is the most common beta hydroxy acid2, or BHA. Naturally occurring, it is obtained from willow bark3.
(In this article, we’ll discuss the practical differences between AHAs and BHAs. However, if you’re interested in chemistry, this article gives a good explanation of the structural difference between alpha and beta hydroxy acids.)
Like AHAs, salicylic acid is widely used as a chemical exfoliant in cosmetic formulations to promote smoother, even skin. However, salicylic acid also has a deeper, pore-unclogging action that makes it the hero ingredient in many anti-acne skincare products. Glycolic acid, lactic acid and salicylic acid are all chemical compounds known as hydroxy acids. While closely related, the first two are part of the alpha hydroxy acid (AHA) family, whereas salicylic acid is the most common beta hydroxy acid2, or BHA. Naturally occurring, it is obtained from willow bark3.
What Does Salicylic Acid do to Skin?
A keratolytic compound4, salicylic acid helps to dissolve or break down the bonds that hold skin cells within the outer layer of skin (stratum corneum). In other words, it promotes the shedding of dead skin cells to reveal a smoother complexion. For this reason, topical salicylic acid is used in the management of acne, as well as dry skin conditions such as psoriasis and dandruff, and in stronger concentrations for the therapeutic removal of calluses and warts5.
While AHAs share this keratolytic or peeling action, there is one major difference. Because AHAS are water-soluble, most of the exfoliating activity occurs on the skin’s surface. Salicylic acid, on the other hand, is oil-soluble. This makes the BHA more compatible with oily skin types, and enables it to get deeper into the pores to remove dead skin cells and clear the pathway of sebum.
As it delivers a dual exfoliation – both on the skin’s surface and inside the pores – salicylic acid is a particularly beneficial ingredient for those with congested, oily and acne-prone skin. And the go-to ingredient for tackling blackheads.
Salicylic Acid for Acne-Prone Skin
Abnormal shedding of cells6 and an excess of oil in acne-prone skin can lead to a ‘plug’ (made from dead skin cells and sebum) forming within a hair follicle (or pore). This clogged hair follicle, or comedo, can be closed – as in the case of whiteheads – or open. Open comedones appear as blackheads, with the discolouration caused by oxidisation when the plug comes in contact with oxygen.
But what about red and inflamed pimples and cysts? When bacteria proliferates within these blocked pores, inflammation occurs. This can result in an ‘eruption’ in the form of a pustule on the skin’s surface.
So, how does salicylic acid work to treat acne? Much of the answer lies in how it exfoliates.
Unlike manual exfoliators and scrubs which can damage the skin and spread bacteria (thereby making acne worse), salicylic acid exfoliates the skin’s surface, while also gently yet thoroughly exfoliating pores from the inside.
As we’ve mentioned, salicylic acid is oil-soluble. This means it is able to cut through oil and lipids to penetrate clogged pores and dissolve plug-forming debris. Not only does this dissolving, deep exfoliating action help with clearing current blemishes, it also helps reduce breakout recurrence.
Salicylic Acid Benefits
It’s clear, then, that salicylic acid has many benefits for those with oily, acne-prone skin. Removing dead skin cells and clearing up excess sebum, it helps to unclog pores and prevent future breakouts.
Here’s a quick snap-shot of salicylic acid’s benefits for acne:
- Improves skin texture by removing dead skin cells on the surface of the skin.
- Helps remove blockages within pores. Dissolving the intercellular glue that binds dead skin cells, it helps prevent clogged pores and can assist in reducing breakout recurrence.
- Soothes breakouts due to anti-inflammatory properties.
- In turn, reduces redness of blemishes.
- Helps prevent blackheads.
- Antibacterial action.
- Helps minimise large pores (by reducing blockages).
- Can be less irritating to sensitive skin than Benzoyl Peroxide (another commonly used acne-fighting ingredient).
- Helps reduce appearance of fine lines and wrinkles.
- Helps reduce pigmentation and signs of sun damage.
Salicylic Acid Side Effects
As it penetrates the pores and increases cell shedding, the main side effects associated with salicylic acid are dryness and sensitivity. Additionally, salicylic acid products are not suitable for those allergic to aspirin, as both belong to a family of compounds called salicylates7. It may also be unsuitable for use if pregnant.
- While generally mild for over-the-counter skincare products (which come in lower percentages), salicylic acid side effects can include:
- Dryness & peeling
- Irritation, stinging, burning
- Flushing, redness, hot sensation
- Allergic reaction, e.g. rash It is important to follow usage instructions and seek medical advice immediately if you think you may be experiencing an adverse reaction.
What Percentage of Salicylic Acid is good for Acne?
While it depends on the type of product, salicylic acid used in over-the-counter skincare is considered most effective at a 1-2% concentration8. Keeping the concentration relatively low helps to minimise the chance of dryness or irritation.
For something stronger, a course of several professional salicylic acid peels for acne may also be recommended by your dermatologist. These are performed in a dermatologist’s office or skin clinic, using a higher percentage of the BHA to resurface the skin.
How to Layer Salicylic Acid
Care should be taken when combining salicylic acid with certain ingredients, particularly retinol. While retinol can also be beneficial for acne-prone skin, products containing salicylic acid should not be layered with those containing retinol, as the combination can be extremely drying. It’s therefore important to space out applications and follow the advice of your dermatologist.
As well as moisturising ingredients to combat dryness, daily use of a high-level, broad spectrum sunscreen is essential in when using salicylic acid. A non-comedogenic, mattifying sunscreen can further assist with reducing shine in acne-prone skins.
Salicylic Acid Products
Salicylic acid is formulated into a range of skincare products, from cleansers to peels, moisturisers and targeted acne treatment products.
Salicylic Acid Cleansers and Gels
As salicylic acid cleansers have limited contact with the skin compared to a leave-on product, a higher percentage may be required for anti-acne benefits. According to the Mayo Clinic, a body wash or soap will be most effective at a 0.5-5% concentration of salicylic acid9.
In La Roche-Posay’s range for oily and acne-prone skin, the Effaclar Micro-Peeling Purifying Gel Cleanser for face and body contains both 2% salicylic acid and salicylic acid derivative, beta-lipohydroxy acid (LHA). Powerfully micro-exfoliating and purifying pores, it is also formulated with Zinc to reduce sebum, and glycerin to prevent unwanted dryness.
Salicylic Acid Cream
Also designed for daily use, salicylic acid creams allow more intensive delivery of the BHA and should be applied after cleansing. If used in the morning, they should always be followed with high-level sun protection.
Effaclar Duo (+) is La Roche-Posay’s daily moisturiser for oily, acne-prone skin, formulated with salicylic acid and LHA to slough away dead skin cells and unclog pores. Soothing redness with niacinamide and helping protect against red and brown marks with procerad, it targets the root cause of acne to minimise and manage breakouts.
With an anti-oxidation and anti-sebum action, Effaclar K (+) is an anti-blackhead moisturiser for combination and oily skin. As well as micro-exfoliating and removing pore build-up with LHA and salicylic acid, it contains mattifying ingredient Airlicium™ and carnosine to reduce oxidation.
Consumer trials revealed a 33% reduction in blackheads in four weeks*. * Cosmetoc-clinical study on 55 subjects.
8. Moghimipour E. Hydroxy Acids, the Most Widely Used Anti-aging Agents. Jundishapur J Nat Pharm Prod.2012.7(1):9-10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3941867/