International non-proprietary name · Benzoyl Peroxide

Benzoyl peroxide: in an analysis pooling 179 trials, it worked best combined with a retinoid

Name: Benzoyl peroxide: in an analysis pooling 179 trials, it worked best combined with a retinoid
Published: 2026-09-16

A network meta-analysis of 179 randomised trials and about 35,000 observations found that the most effective topical option for mild-to-moderate acne was a retinoid combined with benzoyl peroxide, reducing lesion counts by 26.16% more than placebo. In Korea, single-ingredient products are available over the counter.

Last checked Sep 16, 2026

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What it is: A compound that breaks down releasing oxygen. In Korea, single-ingredient products are over the counter — no prescription needed.
What it is used for: Acne, and inflamed acne in particular.
How it is said to work: It is said the oxygen released makes the environment hostile to the acne bacterium, which does not like oxygen. Because it works this way, resistance is thought to be hard for the bacterium to develop.

There are no numbers and no citations in this box. What has been established, and how far, is below.

At a glance

Category: Over the counter — ask the pharmacist
How well established: Strong evidence
Concentration studied: 2.5–5%
Length of the studies: Not disclosed

“Concentration studied” and “Length of the studies” are taken straight from the research on this page. They are not a recommended dose, and the figure for each finding is written out in the text.

This is not how large the effect is but how well confirmed it is. It shows the highest grade among the findings on this page.

Whether and how to use it is decided with a doctor or pharmacist.

Korean classification Over-the-counter medicineVerified against: 의약품안전나라 — 의약품등 정보검색 (품목 허가사항) · Checked on 2026-09-16

Benzoyl peroxide is a topical medicine for acne. It is not a cosmetic, and it is not on Korea's list of functional-cosmetic acne actives — that list holds one entry, salicylic acid at 0.5%, restricted to rinse-off cleansers.

It is not on the prohibited-ingredients list either; we did not find it in Annex 1 of the Regulation on Safety Standards for Cosmetics. It is absent from the cosmetic column not because it cannot go in a cosmetic, but because products using it against acne are regulated as medicines.

What is established

Strong evidenceConcentration studied 2.5–5% · gel

Combined with a retinoid, it was the most effective topical option for mild-to-moderate acne

A network meta-analysis pooling 179 randomised controlled trials, roughly 35,000 observations and 49 treatment classes, published to May 2020. The outcome was percentage change in total lesion count from baseline.

For mild-to-moderate acne the most effective topical option was a retinoid combined with benzoyl peroxide — mean difference 26.16% against placebo (95% credible interval 16.75 to 35.36%).

Chemical peels (salicylic or mandelic acid) scored higher at 39.70% (12.54 to 66.78%), but with a far wider interval, and the authors noted the evidence there was more limited and warrants further research.

Oral treatments — antibiotics, hormonal contraceptives — did not appear effective for mild-to-moderate acne.

This is one of the rare entries on this site carrying strong evidence: 179 pooled trials, placebo comparison, and lesion counts as a clinical endpoint.

Randomised controlled trial in people (179) · 35,000 participants · Compared with vehicle (same formula minus the active) · Funding not declared · Endpoint clinical events (cancers, lesion counts) PMID 35789996 · abstract read

Ingredient dataConcentration studied 2.5–5%

In Korea, single-ingredient products are over the counter; antibiotic combinations are prescription-only

The Korean drug register lists 16 products with benzoyl peroxide as an active ingredient (checked 16 September 2026).

Single-ingredient products such as Benzac AC gel 2.5% are over the counter and can be bought at a pharmacy, while combinations with clindamycin such as Duac gel 3% and 5% are prescription-only.

The same substance is classified differently depending on what it is mixed with. The versions containing an antibiotic are controlled more tightly because of resistance.

Known risks

It bleaches. Towels, pillowcases and clothing lose colour. Keep it off dyed hair too.
Dryness, scaling, redness and stinging are common, which is why low strengths are the usual starting point.
Severe hypersensitivity reactions are rare but reported. If your face swells or you have trouble breathing, stop and seek care immediately.
Evidence that higher concentrations work better is not clear; the increase in irritation is.

What is not established

The figure above belongs to the combination. The effect size of benzoyl peroxide alone is not the number quoted here.
We found no established data on use during pregnancy. Ask a pharmacist or doctor.
The balance of benefit and risk over long-term use is not settled.

Whether and how to use it is decided with a doctor or pharmacist.

What this article relies on

Unless marked otherwise, a paper was read to the abstract. Only papers whose full text we opened are marked as such.

의약품안전나라 — 의약품등 정보검색 (품목 허가사항)식품의약품안전처 · Checked on 2026-09-16
PubMed — 미국 국립의학도서관 문헌 데이터베이스National Library of Medicine · Checked on 2026-09-16