Mitigates BPO-induced erythema, dryness, and barrier disruption while supporting sebum regulation and post-acne mark clearing.
Read the passportSource4
벤조일퍼옥사이드 · 전성분
Benzoyl Peroxide
A potent lipophilic organic peroxide and gold-standard dermatological antimicrobial agent that releases free-radical reactive oxygen species inside pilosebaceous follicles, rapidly killing Cutibacterium acnes without inducing bacterial resistance while dissolving follicular keratin plugs.
GentlenessGentle — four of fiveEvidenceIndicativeTopical
- INCI
- BENZOYL PEROXIDE
Also called BPO · Dibenzoyl Peroxide · Benzoyl Superoxide · Benzoylis Peroxidum
Early-stage page
This ingredient page is still early. We're actively researching before it's ready to stand fully on its own — check back as more sections are verified.
The short answer
Four lines, each compressed from the section it links to. Every line carries the sources of the claim it compresses.
- What it does
Bactericidal Contact Time and Antibiotic-Resistance Protection
See the evidence - Who should pause
eczema or active dermatitis
See safety in full - Where it goes
targeted treatment or cleanser step · day or night
See how to use it - What shows, and when
2 weeks: Noticeable reduction in inflammatory papule and pustule counts and diminished oiliness.
Source1
See the timeline
How to use it
Where it sits in the seven-step ladder, and the record's own fields for the habit.
아침DayDay: used
저녁NightNight: used
day or night
Cleanser클렌저 sits here
Toner토너
Essence에센스
Serum세럼
Eye cream아이크림
Moisturizer크림
Sunscreen자외선차단제
Filled steps are where Benzoyl Peroxide commonly appears. No product is recommended.
Everything here comes from the sources below. None of it is a product recommendation.
- Time of day
- day or night
- Where it sits
- targeted treatment or cleanser step
- Starting frequency
- daily or every other day
- Amount
- pea-sized amount for full face or thin layer on affected areas
- Application
- Apply a thin layer to clean, dry skin on acne-prone areas. For short-contact therapy, apply cleanser or gel for 1 to 5 minutes, then rinse thoroughly with water. Always wash hands after application to avoid bleaching fabrics.
- Storage
- Store in a cool, dry place away from direct heat, open flames, and sunlight. Ensure container is tightly closed.
Plays well with / keep apart
One card per pair. Where the partner has its own passport, the name links to it.
Do layer it with
Combines BPO's bactericidal ROS activity with Adapalene's RAR-selective comedolytic and anti-inflammatory action.
Read the passportSeparate it from
Benzoyl peroxide can oxidize and degrade traditional unencapsulated tretinoin molecules when applied simultaneously.
Apply tretinoin at night and benzoyl peroxide in the morning, or choose encapsulated/stabilized formulations.
What to expect, and when
The record's own timeline. Each step keeps the source of the study it came from.
- Immediate
Bactericidal action begins within 30 seconds to 15 minutes inside C. acnes-colonized follicles at typical concentrations.
Source2
- 2 weeks
Noticeable reduction in inflammatory papule and pustule counts and diminished oiliness.
Source1
- 12 weeks
Significant clearance of facial acne lesions and improved Global Acne Grading System scores in a combination formula.
Source3
Is this safe for me
Everything the record says about suitability, consolidated. Pause-first comes first.
Pause first
- eczema or active dermatitis
- severely compromised skin barrier
- known allergy to organic peroxides
Pause means check first, not never.
Before you start
Can cause initial mild-to-moderate erythema, dryness, peeling, and contact sensitization; bleaches colored fabrics, towels, and hair upon contact.
Best match
acne-prone skin
inflammatory papules and pustules · oily skin · comedonal congestion · antibiotic-resistant acne
Routine
targeted treatment or cleanser step
Pregnancy and breastfeeding
Not medical advice · ask your own clinician
Pregnancy. A 2011 dermatology review of skin-care product safety in pregnancy names hydroquinone (high systemic absorption) and tretinoin (evidence controversial) as the actives of concern, and states that most other topical skin-care products act locally and produce minimal systemic absorption; Benzoyl peroxide is not named among the flagged concerns 4. This is general topical-product reasoning rather than an ingredient-specific safety trial. If you are pregnant, ask your doctor before use.
Breastfeeding. Topical application is applied locally with minimal expected systemic absorption; no ingredient-specific breastfeeding safety trial was located. As a general precaution common to topical actives, avoid applying directly to the breast or nipple area, since incidental transfer to a nursing infant has not been studied for this ingredient. If you are breastfeeding, ask your doctor before use.
| Common, and it usually settles | Stop using it |
|---|---|
| Mild stinging, warmth, or transient dryness upon initial application, followed by gradual skin accommodation within 2 weeks. | severe burning |
| persistent intense swelling | |
| widespread allergic contact dermatitis hives |
Allergen history
Not yet researched
Research in progress — check back soon. How we verify
Who should not use it
Not yet researched
Research in progress — check back soon. How we verify
What it will not do
- The rapid 30-second bactericidal action demonstrated with 5%-10% rinse-off cleansers cannot be replicated by 1.25%-2.5% leave-on gels without sufficient skin contact time.
- The potent antibacterial free-radical oxidation executed by topical benzoyl peroxide does not modulate systemic hormone levels or decrease sebaceous gland size.
- The localized follicular clearance provided by BPO cannot prevent new acne breakouts if discontinued prematurely, as it does not permanently alter genetic predisposition to follicular hyperkeratinization.
The evidence
One card per claim. Concentration, form, population and limitation sit with it, always visible.
Grade legend
- Indicative
- Limited
- Moderate
- Strong
Bactericidal Contact Time and Antibiotic-Resistance Protection
IndicativeAchieves bactericidal clearance of Cutibacterium acnes within 30 seconds at 5% and 10% concentrations (15 minutes at 2.5%, 60 minutes at 1.25%). When combined with the antibiotic clindamycin, protects against the development of antibiotic resistance that occurs with clindamycin used alone, and restores activity against clindamycin-resistant strains.1,2
- Tested concentration
- 1.25% to 10.0%
- Which form
- Micronized Benzoyl Peroxide
- Population and duration
- In-vitro broth microdilution and time-kill assays; 31 clinical C. acnes strains for the resistance-development portion
- Limitation
- Both findings are in-vitro; actual in-vivo skin contact time and antibiotic-resistance protection may vary. The antibiotic-resistance finding is specifically about protecting against resistance to clindamycin when combined, not a claim that bacteria cannot adapt to BPO's own oxidative mechanism in every context.
Inflammatory Acne Lesion Reduction in a Combination Formula
IndicativeA topical medical device cream containing 4% benzoyl peroxide, 0.05% pure retinol, 0.5% retinol palmitate, 1% mandelic acid, and glycyrrhetic acid reduced Global Acne Grading System (GAGS) scores by 39% at the midpoint and 69.2% by week 12, applied twice daily.3
- Tested concentration
- 4.0%
- Which form
- Micronized Benzoyl Peroxide
- Population and duration
- 20 patients with mild-to-moderate facial acne applying the formulation twice daily for 12 weeks
- Limitation
- Open-label single-center pilot study of 20 subjects testing a five-active combination product; the independent contribution of benzoyl peroxide alone is not isolated.
The clinical recordHow it works · Forms · Manufacturing · Regulations · Study ledger · Gaps · Sources
How it works
- Follicular Free-Radical Oxidation
Decomposes inside the pilosebaceous duct to generate reactive oxygen species (ROS) that damage and destroy Cutibacterium acnes cell membranes.
What that rests on: in-vitro microbiological assay
Source1
- Corneocyte Desquamation and Keratolysis
Oxidizes structural desmosomal proteins in hyperkeratotic follicular plugs, accelerating dead cell shedding and clearing comedones.
What that rests on: clinical dermatological evaluation
Source3
Reading the label
| Attribute | Micronized Benzoyl Peroxide |
|---|---|
| Official INCI | BENZOYL PEROXIDE |
| Where it comes from | Synthetic organic peroxide formed by reacting benzoyl chloride with hydrogen peroxide |
| How it is made | Synthesized via controlled oxidation and processed through micro-milling to yield micronized particles suspended in aqueous gels, lotions, or wash bases for enhanced follicular penetration. |
| Gentleness | Potent oxidizing agent that may cause transient dryness, mild erythema, or peeling during the initial weeks of therapy. |
How it is actually made
- Synthesized industrially through the reaction of benzoyl chloride with sodium peroxide or hydrogen peroxide in alkaline aqueous media. The resulting precipitate is washed, purified, wet-milled into micronized crystals, and formulated into hydrous gels or suspensions to ensure chemical stability.
Where the ceiling is set
United States
- The rule
- US FDA OTC Topical Acne Drug Monograph, 21 CFR 333.310(a)
- What it allows
- Benzoyl peroxide is an approved active ingredient for OTC acne drug products at 2.5 to 10 percent, confirmed against the live regulation text.
What the evidence rests on
Study records
In-vitro susceptibility and resistance-development assay2025
Criticality of Benzoyl Peroxide and Antibiotic Fixed Combinations in Combating Rising Resistance in Cutibacterium acnes
For 6 of 7 clindamycin-resistant acne-associated strains, adding BPO enhanced antibiotic activity. Bacterial cultures repeatedly exposed to clindamycin plus BPO did not develop antibiotic resistance, which occurred with clindamycin alone.
Where it falls shortIn-vitro isolated clinical bacterial strains; does not itself demonstrate that bacteria cannot develop resistance to BPO's own oxidative mechanism in general.
Source1
In-vitro time-kill bactericidal assay2022
Minimum Contact Time of 1.25%, 2.5%, 5%, and 10% Benzoyl Peroxide for a Bactericidal Effect Against Cutibacterium acnes
1.25%, 2.5%, 5%, and 10% BPO required 60 min, 15 min, 30 sec, and 30 sec respectively for bactericidal clearance, against both antibiotic-resistant and antibiotic-susceptible strains.
Where it falls shortIn-vitro broth microdilution assay; actual in-vivo skin penetration times may vary.
Source2
Open-label prospective clinical pilot study, 20 patients2019
Clinical evidence on the efficacy and tolerability of a topical medical device containing benzoylperoxide 4%, retinol 0.5%, mandelic acid 1% and lactobionic acid 1% in the treatment of mild facial acne
GAGS score reduced 39% at the midpoint and 69.2% by week 12; comedonic lesions -44%/-65%, papular lesions -49.4%/-62%, pustular lesions -43%/-80% over the same timepoints. Well tolerated with mild, transient side effects.
Where it falls shortOpen-label single-center pilot study with 20 subjects testing a five-active combination product.
Source3
Dermatological narrative review2023
The Rational of a Fixed Combination of Benzoyl Peroxide and Niacinamide in the Treatment of Acne Vulgaris: A Narrative Review
Niacinamide could reduce BPO-related skin irritation and erythema and counteract BPO's negative effect on transepidermal water loss; a fixed combination could optimize efficacy and tolerability.
Where it falls shortReview synthesizing preliminary/preclinical literature; not itself a clinical trial.
Source4
What is still missing
Not yet researched
Research in progress — check back soon. How we verify
Sources on file
- Ghannoum et al. Clin Cosmet Investig Dermatol (2025)(opens in a new tab)
- Boonchaya et al. Clin Cosmet Investig Dermatol (2022)(opens in a new tab)
- Garofalo et al. Clin Cosmet Investig Dermatol (2019)(opens in a new tab)
- Narrative Review, J Cosmet Laser Ther (2024)(opens in a new tab)
- 21 CFR 333.310(a) — US FDA OTC Topical Acne Drug Monograph(opens in a new tab)