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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.

White crystalline powder in a glass dish with a laboratory spatula
Editorial illustration

Salicylic acid is an established topical keratolytic used under U.S. OTC conditions for acne and warts. Concentration, vehicle, treated area, and directions matter, and evidence for consumer acne products should not be transferred to professional-strength peels.1, 4

  • Oil-soluble BHA that exfoliates inside pores1, 4
  • OTC acne standard: 0.5–2% in cleansers, toners, and spot treatments1, 4
  • Also a keratolytic used for warts and dandruff at higher strengths1, 4
  • Historically derived from willow bark; today produced synthetically1, 4

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.3, 1

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.1, 4, 3

Salicylic acid is an established OTC acne active for comedonal acne, within labeled concentrations and directions.

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%.4, 3, 1

Guidelines include topical salicylic acid as an acne option, though comparative evidence is smaller than for some first-line agents.

Skin texture and oil control

moderate evidence

Regular use smooths rough texture and, by clearing congestion, can make pores appear smaller over weeks.3, 1

Keratolysis can improve surface texture and congestion; higher strength or frequency also raises irritation risk.

Wart and corn removal

strong evidence

At 10–40% (medicated plasters and paints), salicylic acid dissolves hardened keratin, a first-line OTC wart treatment.2, 5

Salicylic acid is included in the FDA OTC wart-remover monograph and systematic reviews support a modest benefit with sustained use.

Evidence scope and limitations

The review covers topical salicylic acid used under U.S. OTC acne and wart-remover conditions; cosmetic exfoliation and medical-strength peels are not treated as the same exposure.

  • Concentration, vehicle, treated surface area, and occlusion materially change absorption and irritation.
  • Evidence for OTC acne concentrations cannot be transferred to professional chemical peels.

Evidence last checked: 2026-09-26

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
1, 2

Amounts studied & product use

These figures describe research or common product use, not a personal dose or treatment recommendation.

In skincare studies and products

The FDA OTC acne monograph covers 0.5–2% salicylic acid; wart products use substantially higher monograph concentrations for a different indication. Professional peel evidence and wart-treatment strengths should not be transferred to daily facial cosmetics.

1, 2, 5

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.
1, 2

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.

3, 1

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.1, 4

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.1, 4

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.1, 4

The bottom line

Salicylic acid has clear, use-specific evidence for acne and warts. More concentrated or more frequent use increases irritation without guaranteeing a better result.

References

  1. Rulemaking history for OTC acne drug products. U.S. Food and Drug Administration (2025) · government guidance
  2. OTC Monograph M028: Wart Remover Drug Products for Over-the-Counter Human Use. U.S. Food and Drug Administration (2021) · government guidance · OTC Monograph M028
  3. Management of acne vulgaris: a review. JAMA (2021) · other · PMID 34812859
  4. Guidelines of care for the management of acne vulgaris. Journal of the American Academy of Dermatology (2024) · clinical guideline · PMID 38300170
  5. Topical treatments for cutaneous warts. Cochrane Database of Systematic Reviews (2012) · systematic review · PMID 22972052

Revision history

  1. Replaced search-result citations with exact sources, mapped claims to evidence, and reassessed evidence strength.