It Might Sound Weird, But Here's Why You Should Use Salicylic Acid in Your Hair

There's a good chance you've swiped salicylic acid onto your face as part of your skincare routine. It's a miracle worker when it comes to fighting acne and exfoliating skin. That's because it's a BHA, which means that it's an oil-soluble form of hydroxy acid, so it's able to penetrate deep into your skin's pores. 

One thing you might not know is that salicylic acid is also a great ingredient to add to your haircare routine. You might feel iffy about putting acid on your scalp, but it's worth it—keep reading to find out why.

What are the benefits of using salicylic acid on hair?

Rachel Westbay, MD, FAAD, board-certified dermatologist at Marmur Medical says that salicylic acid gives the most benefits to the scalp rather than the hair itself. Since it improves scalp health, however, salicylic acid may also support hair growth since it's creating a better environment for hair to grow in.

When it comes to scalp health, salicylic acid is particularly useful if you struggle with dandruff. "Because salicylic acid is a keratolytic agent, meaning it exfoliates dead skin cells by breaking cell-to-cell adhesion, it can remove scaly, flaky skin and thus improve the appearance of dandruff," says Westbay. Since buildup of dead skin cells can cause your scalp to itch, salicylic acid can also help relieve itchiness.

"Salicylic acid significantly benefits the scalp," says Shab Reslan, NYC trichologist and hair expert "Having a balanced scalp is the first step to having healthy hair, and can impact hair growth and loss." 

If you have oily hair, salicylic acid will help mitigate some of that oil. "As salicylic acid has a particular affinity for oil, it is incredibly effective at reducing oil on the scalp surface," says Westbay. "This is a benefit because seborrheic dermatitis—the medical condition known to the public as 'dandruff'—is largely caused by a yeast called Malassezia furfur that requires oil to survive. Also, by stripping away the outermost layer of the epidermis, salicylic acid allows oil, dead skin, and product buildup to be washed away."

Which hair types are salicylic acid best for?

Any hair type can use salicylic acid, but you'll get the most benefit from the BHA if you have oily hair or a dry, flaky scalp. Westbay recommends skipping this ingredient if you have sensitive skin unless you ease into it gradually or do a patch test. "I also would advise against using it if the skin on the scalp is broken, irritated, or compromised," she adds.

The best hair products that contain salicylic acid:

This is Maiman's pick for a hair product containing salicylic acid. "This lightweight leave-in treatment is formulated with salicylic acid as well as aloe and colloidal oatmeal to fight irritation and help relieve dryness," she says.  The addition of charcoal helps to mattify and reduce oil. I really like that the sheer formula doesn't weigh down hair or interfere with styling. It can be applied directly to the scalp when hair is dry or damp and massaged in.

This scalp serum is all about calming inflammation and oil production. With salicylic acid to exfoliate, an ingredient called Fluidipure 8G to neutralize scalp redness, and panthenol to hydrate, it's a powerhouse for a healthier head of hair. "I recommend using this before every other shampoo day until the build-up is clear, then continue on a regular weekly or bi-weekly schedule to maintain a balanced, healthy and clear scalp environment ideal for your best hair growth," says Reslan.

If you're looking for the ultimate dandruff relief, this scalp conditioner is both soothing and effective.  Climbazole and piroctone olamine help get rid of dandruff, and a blend of rosemary oil, menthol, salicylic acid, ginger extract, and oat helps calm an irritated scalp. 

This clarifying serum enlists the help of both AHAs and BHAs by blending salicylic acid with glycolic acid. These two hydroxy acids ensure exfoliation and oil dissolution, niacinamide aids in healthier hair growth, and micellar water gently removes impurities. 

Scalp scrubs have the benefit of being both effective and feeling like a treat. This one contains rice as a gentle physical exfoliator but also has salicylic acid as a chemical exfoliant. Plus, it's hydrating and nourishing to boot. Work it into hair for two or three minutes for best results. 

If your scalp is feeling dull and in need of a refresh, this anti-dandruff shampoo has both salicylic acid and caffeine to exfoliate and rejuvenate. It's color safe, so you don't have to worry about it stripping your hair. 

If you've tried everything to no avail, it's time to call in this treatment shampoo. Salicylic and lactic acids work together to clarify and remove dead skin and buildup from the scalp. With 3% salicylic acid, this shampoo is a heavy hitter. Plus, cooling agents peppermint, tea tree, and spearmint oil help provide relief for a stressed-out scalp. 

This dandruff-fighting shampoo from Neutrogena is a consistently reliable choice for stubborn flakes. It uses salicylic acid as its main ingredient to treat the scalp and leave it refreshed. 

Keratin helps improve hair strength, while salicylic acid purifies the scalp. This shampoo makes hair feel lighter and provides tons of volume. 

Use this shampoo whenever you wish your hair had a reset button. Apple cider vinegar helps detox your scalp, and salicylic acid lifts oil.

A soothing mask is just what the doctor ordered for an inflamed, itchy scalp. This two-pack of masks protects hair while exfoliating and calming. Leave it on for up to 20 minutes for a luxe ritual.

Calling all blondes! This shampoo was formulated with light hair in mind by helping preserve color while it helps your scalp be its healthiest. 

Consider this a primer for your head. Use before you shampoo to prep your scalp before you wash and style. It soothes itchiness while treating irritation. 

Salicylic acid works in tandem with tea tree oil to provide fast relief. This two-in-one product helps clear up dry skin and redness.