Salicylic Acid
sal-ih-SIL-ik AS-id
What Is Salicylic Acid?
Salicylic Acid is a beta hydroxy acid (BHA) derived from willow bark that is oil-soluble, allowing it to penetrate into pores and dissolve sebum buildup. It is a proven exfoliant for the scalp and is the active ingredient in many medicated dandruff shampoos. Its ability to dissolve the glue holding dead skin cells together makes it excellent for treating flaky, buildup-prone scalps.
Source: Willow bark (natural) or synthesized from phenol
Origin: Semi-synthetic
Also known as: BHA, Beta Hydroxy Acid, 2-Hydroxybenzoic Acid
What Does Salicylic Acid Do to Your Hair?
Salicylic Acid dissolves the intercellular lipid bonds that hold dead skin cells together on the scalp surface, promoting gentle exfoliation. It penetrates into hair follicles and pores to dissolve excess sebum and product buildup. It also has anti-inflammatory and mild antimicrobial properties that help reduce scalp irritation and dandruff symptoms.
Best For
Dandruff-prone scalp, product buildup, oily scalp, scalp psoriasis, seborrheic dermatitis
Not Recommended For
Very dry scalp, sensitive skin with compromised barrier, open scalp wounds
Concentration Matters
0.5-3%
Hair Type Compatibility
Method Compatibility
Safety & Regulation
Safe at OTC concentrations (1-3% for scalp products). Can cause dryness and irritation if overused. Not recommended during pregnancy (though topical scalp use is generally considered low risk). May increase sun sensitivity. Should not be used with other strong exfoliants simultaneously.
FDA Status: Approved
FDA-approved as an OTC active ingredient for dandruff and seborrheic dermatitis treatment at 1.8-3% concentration. Also approved for acne and wart removal at different concentrations.
EWG Score: 3/10
HairAide Verdict
Salicylic Acid is one of the most effective scalp exfoliants available and HairAide's top recommendation for anyone dealing with flaky, buildup-heavy scalps. Use a salicylic acid shampoo once or twice a week and follow with a moisturizing conditioner. It provides visible improvement in scalp flaking within just a few uses.
Products That Contain Salicylic Acid
Anti-dandruff shampoos, scalp scrubs, clarifying treatments, scalp serums
Alternatives to Salicylic Acid
If you want to avoid Salicylic Acid, look for products with these ingredients instead:
Zinc Pyrithione, Ketoconazole, Glycolic Acid, Tea Tree Oil
Frequently Asked Questions
Yes, Salicylic Acid has a safety rating of 7/10 and is generally considered safe for use in hair products. Safe at OTC concentrations (1-3% for scalp products). Can cause dryness and irritation if overused. Not recommended during pregnancy (though topical scalp use is generally considered low risk). May increase sun sensitivity. Should not be used with other strong exfoliants simultaneously.
Salicylic Acid is CG-method approved and is generally considered safe for curly hair.
Yes, Salicylic Acid is approved for the Curly Girl method.
Some alternatives to Salicylic Acid include: Zinc Pyrithione, Ketoconazole, Glycolic Acid, Tea Tree Oil
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