Ingredient Beauty BenefitsAcid · Salicylic Acid
Salicylic acid: the evidence comes from clinic-strength peels, and Korea's cosmetic limit is 0.5%
Most acne trials used 30% peels performed in a clinic. What Korea allows as an acne functional claim is 0.5%, and only in rinse-off cleansers. There is a sixtyfold gap between those two numbers.
Last checked Sep 16, 2026
- In pregnancy
- ! Use with care
- Irritation
- Moderate
- Daytime use
- ! Sunscreen required
Not a measurement — reported irritation grouped into five steps. It varies between people. If you are pregnant or breastfeeding, check with a doctor or pharmacist before use. This page is not medical advice.
Salicylic acid is oil-soluble, so it is described as reaching inside pores filled with sebum. Chemically that description is unobjectionable.
The question is what concentration the evidence came from. Search the literature and the acne trials are mostly 30% peels — a clinic procedure, not something you use at home. The evidence at cosmetic strengths is a separate matter, and thinner than you would expect.
Contents
What is established
The same ingredient at a different strength, in a different formula, is a different product. These are the conditions the studies used.
Korea's listed acne amount is 0.5%, and only for rinse-off products
Annex 4, item 6 of the Regulation on the Review of Functional Cosmetics lists exactly one active for acne: salicylic acid at 0.5%.
Three conditions come with it. The product type is restricted to human cleansing products (soap-based preparations); the forms allowed are lotion, solution, cream and solid; and the directions are fixed as 'rinse off thoroughly with water immediately after use'.
So under Korean rules, the only salicylic acid products that may carry 'helps relieve acne-prone skin' are rinse-off cleansers. A leave-on toner or serum with the same ingredient at the same strength may not use that wording.
Benzoyl peroxide and adapalene are not on this list. In Korea they are licensed as acne medicines, not cosmetics.
A 30% peel worked, but it was compared against another peel
A double-blind, split-face randomised trial in 36 people, almost all Fitzpatrick type IV–V. One side received a 30% salicylic acid peel, the other Jessner's solution.
Both sides showed clear reductions from baseline in inflammatory and non-inflammatory lesion counts and in post-acne hyperpigmentation scores (P < .001 for each). But there was no significant difference between the two. Burning, stinging and exfoliation were the common complications.
What this supports is 'a 30% salicylic acid peel does about as much as Jessner's solution'. With no vehicle arm, the trial cannot say whether peeling beats doing nothing.
And 30% is a clinic procedure strength. It is a different object from the cosmetics this page covers.
- Randomised controlled trial in people · 36 participants · Compared with another active ingredient · Funding not declared · Endpoint scores from blinded assessors PMID 32447767
We could not find acne evidence at cosmetic strengths (0.5–2%)
At the 0.5–2% used by toners and serums on the shelf, we found no human trial counting acne lesions against a vehicle control (PubMed, checked 16 September 2026).
Absence is not proof of no effect. But the sentence 'salicylic acid is a proven acne ingredient' usually cites the peel trials above, at 15 to 60 times the strength of what you buy for home use.
If evidence turns up, this entry and its level will change.
How to use it
- Starting with a rinse-off product is the safer route, and it is where the Korean functional evidence sits.
- With leave-on products, start two or three times a week and see what your skin tolerates.
- Do not layer it with retinol on the same night. Irritation rises sharply.
- Use sunscreen while your stratum corneum is thinning. The photosensitivity data are not as clear as for AHAs, but there is nothing to lose.
Cautions
- In pregnancy this needs checking, particularly at high strengths over large areas. Ask a doctor or pharmacist.
- Avoid it if you are allergic to aspirin and related salicylates.
- Acne is a medical condition. Cosmetics are not for treating disease; with significant inflammatory acne, seeing a clinician is faster.
- A 30% peel is a clinic procedure. Do not improvise one at home because the ingredient name matches.
With a new ingredient, apply a small amount somewhere inconspicuous, such as the inner arm, for two days first. Stop if it reddens or stings.
Related skin concerns
What this article relies on
- 기능성화장품 심사에 관한 규정 [별표 4] 자료제출이 생략되는 기능성화장품의 종류 — 식품의약품안전처고시 제2025-88호식품의약품안전처 · 시행 2025-12-16 · Checked on 2026-09-16
- 화장품법 시행규칙 제2조(기능성화장품의 범위) — 총리령 제2109호식품의약품안전처 · 시행 2026-04-02 · Checked on 2026-09-16
- PubMed — 미국 국립의학도서관 문헌 데이터베이스National Library of Medicine · Checked on 2026-09-16