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Tuesday, October 13, 2026Index last updated Oct 9
The Index  ·  Beta-hydroxy acid

Salicylic acid

Salicylic Acid

Oil-soluble exfoliant with decades of acne data; capped at 2 % in EU leave-on products.

StrongMultiple RCTs, consistent
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Written bytheskindex
Reviewed byNot yet reviewed
Last updated19 Sept 2026
Sources3 cited

Salicylic acid is a lipophilic hydroxy acid, which is why it can work inside the sebum-filled follicle where water-soluble acids can't. It loosens corneocyte adhesion, has mild anti-inflammatory activity (it is the active metabolite of aspirin), and thins the follicular plug[3].

The evidence

Low-concentration daily use (0.5–2 %) reduces both comedonal and inflammatory acne lesions in controlled trials[1]. As a professional peel at 20–30 % it improves texture and post-inflammatory pigmentation[3].

Limits

The EU caps leave-on products at 2 % following the SCCS's 2019 review, which was driven by systemic exposure modelling rather than skin irritation[2]. Pair with niacinamide; alternate with retinol rather than layering.

Evidence by claim

Graded separately; the entry grade is the best-supported claim
Reduces comedones and inflammatory acne lesions[1][3]
Strong
Improves texture and pigmentation as a peel (20–30 %)[3]
Moderate

Safety & limits

Source and region, always
2 % · leave-on — Maximum 2 % in leave-on and 3 % in rinse-off products (other than shampoo); not for children under 3 except shampoo.[2] EU UK
2 % · leave-on — OTC acne monograph permits 0.5–2 %. US
2 % · leave-on — Hotlist limit 2 % for leave-on cosmetics; higher concentrations are drugs. CA

Sources · 3

Numbered as cited in the text
  1. [1]Zander E, Weisman S. Treatment of acne vulgaris with salicylic acid pads. Clinical Therapeutics (1992)
  2. [2]Scientific Committee on Consumer Safety (SCCS/1601/18). Opinion on salicylic acid (CAS 69-72-7) (2019)regulation
  3. [3]Arif T. Salicylic acid as a peeling agent: a comprehensive review. Clinical, Cosmetic and Investigational Dermatology (2015)doi:10.2147/CCID.S84765

Revision history

16 Sept 2026Entry createdTheSkindex Desk