What is salicylic acid and how does it clear up spots?
There's a bewildering number of skincare ingredients out there that claim to help balance our complexions, but salicylic acid is the one that's really worth knowing. It's stood the test of time and gets a united seal of approval from derms for its ability to fight acne, unclog pores, control oil and calm skin.
Few ingredients dive into pores and extinguish blemishes quite like it. But how exactly does salicylic acid work? And how should you use it to maximise its benefits, without overstimulating your skin?
To find out, we asked a host of respected skin experts to break down this ingredient, what its benefits are, who should (and shouldn't) use it and how to incorporate it into a routine for the best results.
- What is salicylic acid?
- How does salicylic acid work?
- What are the benefits of salicylic acid for skin?
- What is the difference between salicylic acid and glycolic acid?
- Can you use salicylic acid every day?
- Can salicylic acid damage your skin?
- Who should avoid salicylic acid?
- What are the best salicylic acid products to fight acne?
Best salicylic acid skincare
What is salicylic acid?
Salicylic acid is a type of exfoliating acid called a Beta Hydroxy Acid (BHA). It gently dissolves the sticky glue that binds oil and dead skin cells together inside your pores. In doing so, it helps to disperse the gunk that can build up and turn into spots.
It can improve the look of bumpy ‘chicken skin’ (a.k.a keratosis pilaris) and reduce the scaly skin associated with psoriasis. Salicylic acid is also responsible for the anti‐inflammatory action in aspirin, so it's good for calming angry flare-ups.
Originally derived from white willow bark, salicylic acid is now predominantly created in a lab. You can find salicylic acid in everything from salicylic acid cleansers to body washes and serums.
How does salicylic acid work?
Salicylic acid is a tiny skin compound that has the ability to actually enter pores, rather than showboating about on top. One way salicylic acid does this is by travelling through the skin barrier, a protective layer made up of oily lipids.
"Because a blocked pore is deep, you have to get past this waterproof barrier by mimicking the lipid structure," notes skin and laser expert Debbie Thomas. “An oil-soluble [also known as lipid-soluble] ingredient like salicylic acid does just that.”
In terms of benefits, this means salicylic acid is able to penetrate deep into pores to exfoliate skin from within, explains Dr Jason Thomson, dermatologist and Head of Medical at Skin & Me.
Seriously worth the hype.
What are the benefits of salicylic acid for skin?
While it's tempting to over-cleanse or over-exfoliate to help prevent breakouts, this is far more likely to make matters worse. As soon as you disrupt the skin's top layer (also called the skin barrier), it produces more oil to compensate for the dryness.
A simpler and more effective approach is to incorporate salicylic acid into your routine because it dissolves the blockages – such as oil, dead skin and leftover makeup – that can make such a huge difference to spots. Here's how it can help…
Salicylic acid is mainly used to minimise breakouts. Spots may be most visible on the surface of the skin, but they actually form inside the hair follicles. Pores that aren't properly ‘cleaned out’ often result in pimples, blackheads, whiteheads and other blemishes.
According to Debbie, there are three stages to a spot. "The first is an overproduction of oil and excess dead skin build-up that creates the blocked pore and blackhead. Then the bacteria get into the blocked pore, where they are able to grow. The body wants to destroy it, which is when you get the redness and swelling," she adds.
The beauty of salicylic acid is that it's closely associated with aspirin, which also comes from the willow tree family. “By using salicylic acid on a spot, you can prevent and reduce the inflammation that often leads to scarring and pigmentation marks,” Debbie adds.
And, alongside the work it does inside pores, salicylic acid also gently exfoliates the surface of the skin to lift away the grime and dead cells that block pores in the first place. "Clearing away the dead and dry skin on the surface allows salicylic acid to operate more effectively in clearing clogged pores, keeping oil at bay and preventing blemishes,” confirms Dr Murad.
Psoriasis is a common autoimmune skin condition that can lead to scaly patches on the knees, elbows, upper body and scalp. “Psoriasis causes an acceleration in skin cell turnover,” Dr Thomson explains. “Salicylic acid can be used to treat it because it can break down the bonds holding the skin together, making it softer and allowing it to shed more easily.”
Salicylic acid also has anti-inflammatory properties, which is why it's often found in prescription creams for psoriasis as well as many over-the-counter creams.
Keratosis pilaris, commonly referred to as 'chicken skin’, is characterised by small, hard bumps on the upper arms, thighs and cheeks. “The bumps are caused by a buildup of keratin, a key protein in skin, hair and nails,” says Dr Thomson.
“In keratosis pilaris, the keratin forms a scaly plug that blocks the opening of the hair follicle, leading to patches of rough, bumpy skin,” he continues. “Salicylic acid can help improve the appearance of keratosis pilaris over time by softening and exfoliating these keratinous skin bumps.”
What is the difference between salicylic acid and glycolic acid?
Both salicylic and glycolic acids are classed as hydroxy acids and chemical exfoliants. But that's where the similarities end.
“Glycolic acid is an alpha-hydroxy acid (AHA), whereas salicylic acid is a beta-hydroxy acid (BHA) with bigger molecules as it works superficially on the skin's surface,” says GP and aesthetician Dr Ahmed El Muntasar. Salicylic acid is small enough to enter and de-clog pores, but “glycolic acid has even smaller molecules, so it goes deeper and stimulates collagen production,” Dr El Muntasar explains.
Can you use salicylic acid every day?
Most people can use salicylic acid every day but it depends on the product and your individual skin tolerance.
Skin specialist and A-list facialist, Shane Cooper, says: “If it's a small amount of salicylic acid in a cleanser, for example, it is generally OK for everyday use [for most skin types]. But if it is in any other skincare product, I would recommend using it in moderation as salicylic acid can sometimes irritate the skin.”
In practical terms, this means using a salicylic acid serum once a week if you have sensitive skin; otherwise, start with three times a week and work up from there, adds Shane.
Can salicylic acid damage your skin?
With a few exceptions, salicylic acid is generally tolerated by most skin types. But there is one key side effect to be aware of. “Salicylic acid can be drying,” says Debbie, “which may lead to flaking and then irritation." So, use it in moderation (as suggested above) and rehydrate skin by ensuring you're topping up the hydration levels with a good barrier-building moisturiser.
It's also important to wear sunscreen while using salicylic acid-based skincare. “Salicylic acid, like retinoids, can increase your skin's sensitivity to the sun and lead to quicker sunburns and skin damage,” Dr Thomson notes. “Use a sunscreen with an SPF of at least 30, even on cloudy days, and limit sun exposure while using products with salicylic acid,” he says.
The answer to your skincare prayers.
Who should avoid salicylic acid?
While salicylic acid is excellent for those with oily and acne-prone skin, not all skin types can tolerate this ingredient. “You shouldn’t use salicylic acid if you are allergic to aspirin,” warns Shane. “Those with super sensitive skin or rosacea may also want to avoid it, as salicylic acid can cause irritation.”
Overall, salicylic acid is safe to use during pregnancy, says Shane. “But be aware that skin can change and become more sensitive as a result of hormone changes,” he adds.
What are the best salicylic acid products to fight acne?
To work, salicylic acid needs to be in a high enough percentage – between 0.5%-2% –rather than be buried at the bottom of an ingredients list.
The salicylic acid product you decide to incorporate into your routine comes down to personal choice, but as Debbie points out, "it is important not to overuse it and to balance active products containing salicylic acid with nourishing ones.”
1. Salicylic spot patches
Pimple patches are a great option for treating surface-level breakouts while also helping to prevent picking, which can speed up the healing process.
One of our top picks is Starface's Hydro-Star + Salicylic Acid Patches. These combine hydrocolloid with 1% salicylic acid to help shrink blemishes and can be worn both day and night. Clinically proven to draw out bacteria, they’re designed to visibly reduce pimples – often in just one night.
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For on-the-spot relief, apply Kate Somerville Eradikate Blemish Spot Treatment or Murad Rapid Relief Spot Treatment directly to an emerging pimple with a clean cotton bud.
A salicylic acid cleanser, such as the No7's Derm Solutions Salicylic Acid Purifying Cleanser or CeraVe SA Smoothing Cleanser is a generally good starting point.
You may prefer to sandwich your spot-fighting treatment between your cleanser and serum, in which case a clarifying lotion (a little like a toner or an essence) might be a better fit.
Good options include La Roche-Posay Effaclar Clarifying Lotion, which has the added benefit of containing the brand's soothing thermal spring water for sensitive skin types, Paula’s Choice Skin Perfecting 2% BHA Liquid Exfoliant and Medik8 Press and Clear.
Serum buffs may like to switch to 111Skin's 3 Phase Anti Blemish Booster – a triple threat of salicylic acid, anti-bacterial colloidal silver and kojic acid to unclog pores, minimise redness and improve the look of post-acne hyperpigmentation.
Or simply add one to two drops of Pai Salicylic Acid Clarifying Booster, which contains 100% natural salicylic acid derived from white willow bark and wintergreen, into your regular serum.
Check out our helpful guides on banishing acne on different parts of your body, hormonal acne, back acne and how to get rid of acne scars.
In need of professional skin help? Check out our guide to every type of facial to figure out your treatment options.
