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Skin Actives

Salicylic Acid

Also known as: BHA, Beta hydroxy acid, 2-Hydroxybenzoic acid

The oil-soluble exfoliant (BHA) that clears pores from the inside — the workhorse of acne skincare and the anti-acne OTC drug standard.

  • By IngredientWiki Editorial Team
  • Fact-checked by IngredientWiki Editorial Team
  • Updated 2026-09-25
  • 2 min read

In short

Salicylic acid is a beta hydroxy acid (BHA) with one property that made it the cornerstone of acne treatment: it is oil-soluble. Unlike water-soluble AHAs that work on the skin's surface, salicylic acid penetrates into oil-filled pores, dissolving the debris that forms blackheads and breakouts, while also calming inflammation. Originally derived from willow bark, it is now produced synthetically and is an FDA-recognized OTC acne drug ingredient at 0.5–2%.

  • Oil-soluble BHA that exfoliates inside pores
  • OTC acne standard: 0.5–2% in cleansers, toners, and spot treatments
  • Also a keratolytic used for warts and dandruff at higher strengths
  • Historically derived from willow bark; today produced synthetically

What is Salicylic Acid?

Salicylic acid's story begins with willow bark, whose pain-relieving and fever-reducing properties led to aspirin (acetylsalicylic acid). In skincare, it is used as an exfoliant with a unique twist: being oil-soluble, it travels through sebum to work inside the pore, breaking down the glue between dead skin cells where most water-based actives never reach. That makes it the standard first-line OTC ingredient for blackheads, whiteheads, and mild acne.

Where it comes from

Natural sources

  • Willow bark and wintergreen leaves (historical sources of salicin/salicylic acid)

How it's made

Modern cosmetic and pharmaceutical salicylic acid is synthesized chemically.

What it does in products

  • Keratolytic: dissolves dead-cell bonds inside pores
  • Anti-inflammatory action on active breakouts
  • Regulates pore congestion (blackheads, whiteheads)
  • Higher strengths remove warts, corns, and scalp scale

Benefits

Clearing blackheads and whiteheads

strong evidence

By dissolving the plug of dead cells and sebum inside pores, salicylic acid directly targets comedonal acne — the kind that is hardest to reach with surface exfoliants.

Treating mild inflammatory acne

strong evidence

Salicylic acid is an FDA OTC monograph acne ingredient, with decades of trial data showing modest but real reductions in pimples and lesions at 0.5–2%.

Skin texture and oil control

moderate evidence

Regular use smooths rough texture and, by clearing congestion, can make pores appear smaller over weeks.

Wart and corn removal

strong evidence

At 10–40% (medicated plasters and paints), salicylic acid dissolves hardened keratin, a first-line OTC wart treatment.

Side effects & safety

Dryness and flaking (common)Especially during the first weeks; start 2–3 times per week and increase gradually.
Stinging on broken or over-exfoliated skin (uncommon)Do not apply to open wounds or raw, peeling areas.
Salicylate sensitivity reactions (rare)People allergic to aspirin or NSAIDs should patch-test; avoid use on large body areas.

Safety considerations

  • Low-concentration topical use on small areas is generally considered acceptable, but many obstetric guidelines advise avoiding salicylic acid peels and large-area application during pregnancy. Ask your provider.
  • Combining with retinoids, benzoyl peroxide, or AHAs increases irritation — split them across days or day/night.
  • Increases sun sensitivity; daily sunscreen is recommended.
  • Not for: Aspirin/NSAID allergy (caution), broken or infected skin

How it's used

In skincare

Daily products: 0.5–2% in leave-on or rinse-off formats. Begin with a 0.5–1% formula two to three nights per week. Higher concentrations (up to 30%) are professional peels; 10–40% medicated products treat warts.

Regulatory status

  • Salicylic acid is an FDA OTC monograph drug ingredient for acne (0.5–2%) and for wart removal (10–40%). In general cosmetics it is used under the FD&C Act.
  • INCI name on cosmetic labels: Salicylic Acid.
  • The CIR Expert Panel has assessed salicylic acid as safe in cosmetics within concentration limits.

Popular products containing Salicylic Acid

  • Skin Perfecting 2% BHA Liquid Exfoliant — The iconic leave-on BHA tonerPaula's Choice · skincare
  • SA Cleanser — Gentle daily wash-off optionCeraVe · skincare
  • Oil-Free Acne Wash — Classic 2% drugstore cleanserNeutrogena · skincare

Product names and brands are shown for reference and belong to their respective owners.

BHA vs AHA: which one do you need?

Both are chemical exfoliants, but they specialize differently. BHAs (salicylic acid) are oil-soluble and penetrate pores — ideal for blackheads, oily skin, and breakouts. AHAs (glycolic, lactic) are water-soluble surface exfoliants — better for dullness, texture, and dry skin. Combination skin often benefits from alternating both, while sensitive skin should choose one at a low concentration.

Frequently asked questions

How often should I use salicylic acid?

Start with two to three nights per week and increase to nightly or every other night if tolerated. Wash-off products (cleansers) can be used daily with less risk, but leave-on formulas deliver more of the active.

Can I use salicylic acid and retinol together?

They target different aspects of acne and can be combined by alternating nights, or by using salicylic acid in the morning and retinol at night. Using both at once raises irritation risk, especially early on.

Does salicylic acid thin the skin?

No — the opposite is true at typical concentrations. By removing the outer dead layer, it temporarily thins the stratum corneum visually, but regular exfoliation has been shown to stimulate a healthier, denser epidermis over time.

The bottom line

Salicylic acid is the go-to OTC active for congested, breakout-prone skin because it works inside the pore, not just on the surface. Use it 2–3 times weekly at 0.5–2%, expect a few weeks of adjustment, and pair it with sunscreen and a simple moisturizer.

References

  1. Salicylic acid compound summary. PubChem (National Library of Medicine). https://pubchem.ncbi.nlm.nih.gov/compound/338
  2. Rulemaking history for OTC acne drug products (salicylic acid monograph). U.S. Food and Drug Administration. https://www.fda.gov/drugs/status-otc-rulemakings/rulemaking-history-otc-acne-drug-products
  3. Salicylic acid in dermatology — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=salicylic+acid+acne+vulgaris
  4. Cosmetic Ingredient Review — salicylic acid safety assessment. Cosmetic Ingredient Review. https://www.cir-safety.org/ingredients