Does benzoyl peroxide help acne scars?

Benzoyl peroxide is an acne medicine. It kills the bacteria that make pimples red, and by clearing acne it lowers the number of pimples that could leave a scar or a dark mark. No trial Skinli found shows it fading or smoothing scars you already have. This guide explains the difference between scars and marks, what benzoyl peroxide can and cannot do for each, what trials of benzoyl peroxide gels found about new scars, and what treats existing scars. For the ingredient as a whole, see the benzoyl peroxide guide.

Skinli gives general education. A dermatologist is the right person to assess and treat acne scars.

Scars and marks are different

People use "acne scar" for two different things:

	Acne scar	Acne mark
What it is	A change in the skin's shape: a pit or a raised bump	A flat change in color, such as red or brown, left after a pimple
Why it happens	The body made too little or too much collagen while healing	The AAD calls dark spots after acne hyperpigmentation
Does it fade on its own?	The AAD says scars "can fade" but "rarely go away"	The AAD says dark spots "can last much longer than the acne"
What treats it	Retinoids for mild scars; procedures for deeper ones	Sunscreen, and ingredients such as azelaic acid or a retinoid

The American Academy of Dermatology (AAD) explains the collagen part: "If your body makes too little collagen, depressions or pits form as your skin heals," and "when your body makes too much collagen," you see a raised scar. Collagen is the protein that gives skin its support. Skinli's guide to types of acne scars covers each kind, and how long dark marks take to fade covers marks.

What causes acne scars

The AAD says scars are more likely when you:

• "Had acne that went deep into your skin, like a deep and painful pimple, such as an acne cyst or nodule." It adds, "the deeper the acne goes into your skin, the more likely it is to cause a scar."
• "Picked, popped, squeezed, or scratched the acne."
• "Have a close blood relative who gets acne scars."

It also says "it is not possible to predict who will develop acne scars." Some people with every risk never scar, and some with none do.

Where benzoyl peroxide fits: prevention

The AAD's advice on acne in skin of color puts it simply: "Prevent dark spots and scars by treating acne early." It says "studies show that treating acne when it's just beginning can prevent acne from getting worse," and that when acne becomes moderate to severe before treatment starts, people with skin of color have a higher risk of dark patches and keloids, a type of raised scar.

Benzoyl peroxide is one of the treatments that clears acne. The AAD's 2024 acne guideline gives it a "strong" recommendation, and the AAD says it "reduces acne-causing bacteria on your skin." Fewer inflamed pimples means fewer chances for a scar to form. That is its role for scars, and it is a useful one.

What the trials found about new scars

Two trials tested a prescription gel that combines adapalene, a retinoid, with benzoyl peroxide. Both used a split-face design: one side of each person's face got the medicated gel and the other side a gel without medicine.

Trial	People	Gel	After 6 months, medicated side	Side without medicine
2017, Journal of the European Academy of Dermatology and Venereology	31 adults with moderate acne and 10 or more scars	Adapalene 0.1% / benzoyl peroxide 2.5%	Scar count stayed level; mean 11.58 scars	Scar count rose; mean 13.55 scars
2018, American Journal of Clinical Dermatology	67 people with moderate or severe acne and 10 or more scars	Adapalene 0.3% / benzoyl peroxide 2.5%	Scar count fell 15.5%; mean 9.5 scars per half face	Scar count rose 14.4%; mean 13.3 scars per half face

In the 2017 trial, the share of people whose scars were rated "almost clear (hardly visible scars)" rose from 9.7% to 45.2% on the treated side and did not change on the other. Acne spots fell by 65% on the treated side and 36% on the other. The 2018 trial was funded by Galderma, a company that sells an adapalene and benzoyl peroxide gel, and its investigators were paid to run the study. The 2017 trial had 31 people, which its authors list as a limitation.

These trials show that treating acne well, with both ingredients, can stop scars from increasing. They cannot say how much of the effect came from benzoyl peroxide and how much from adapalene, a retinoid, which the AAD says can help with scarring on its own. No trial Skinli found tested benzoyl peroxide alone on scars.

Matching each problem to a treatment

Problem	What the sources say treats it	Where benzoyl peroxide fits
Active pimples	Benzoyl peroxide, retinoids and other acne medicines	Treats them, which prevents new scars
Pitted scars	Procedures that make new collagen, and retinoids for mild scars	No trial Skinli found shows it filling pits
Raised scars and keloids	A dermatologist's treatment	No trial Skinli found tests it
Dark marks	Azelaic acid or a retinoid, and daily sunscreen	Prevents new marks by clearing acne

For marks, the AAD says "azelaic acid can also treat the dark spots that appear when acne clears," and "if you develop dark spots after acne clears, a retinoid can help lighten these spots." For skin color, the AAD calls the worry that benzoyl peroxide causes light spots on the skin "a myth." See does benzoyl peroxide bleach.

What treats existing scars

The AAD says "if you have mild acne scarring, a retinoid or salicylic acid can make scarring less noticeable." For deeper scars, dermatologists use procedures, and the AAD says the plan depends on "the type of acne scars you have, how many scars you have, your age and skin tone, your budget" and other factors. The AAD lists these treatments for depressed, or pitted, scars:

Treatment	What the AAD says it does
Chemical peel	Helps the body make more collagen and elastin, so pits look less noticeable
Fillers	Add volume to depressed scars; most give temporary results
Laser treatment	Resurfaces the skin; as it heals, it makes collagen and elastin
Microneedling	Tiny needles puncture the skin so it makes new collagen and elastin
Radiofrequency	Waves help the skin make collagen and elastin
Scar surgery	Removes or lifts a scar

Raised scars "require different treatment," the AAD says, because they form when the body makes too much collagen. Skinli's acne scar treatment guide compares the options, and tretinoin for acne scars covers the retinoid most studied for scars.

A routine that treats acne and marks together

The AAD recommends "treating acne and dark spots at the same time." Skinli's 12-week plan does this:

Time	Steps
Night	Gentle face wash; benzoyl peroxide 2.5% gel and adapalene 0.1% gel on the whole area that gets pimples; moisturizer
Morning	Gentle face wash; moisturizer; azelaic acid 10% cream from week 5 for flat marks; sunscreen SPF 30

The gels treat the acne, which prevents new scars and marks. The azelaic acid cream works on flat marks, and sunscreen keeps them from darkening. The plan adds the mark cream only when photos show flat red or brown marks. The free Skinli acne plan decides this from a photo of your skin.

Strength and scars

A stronger benzoyl peroxide does nothing extra for scars. For acne itself, a 1986 study found 2.5% cleared red pimples as well as 10% with less irritation, and the AAD advises starting with 2.5% to avoid "dry, irritated skin or a burning sensation." Irritated skin looks redder, which can make marks look worse for a while. The strengths guide covers the numbers.

Protecting skin while acne clears

• Do not pick. The AAD lists picking, popping, squeezing and scratching as causes of scars.
• Use sunscreen every day. Skinli's plan uses SPF 30 each morning, because sun makes marks darker.
• Give treatment time. The AAD says acne treatment takes "at least 6 to 8 weeks before you start to see fewer breakouts." Keep using the same treatment for that whole time instead of switching products every week.
• Treat deep acne early. Painful nodules and cysts are the acne most likely to scar, and they need a doctor, not only store products.

When to see a dermatologist

See a dermatologist if you have deep, painful acne, if new scars keep forming, or if you want treatment for scars you already have. A dermatologist can match treatment to your scar type and skin tone. Skinli gives general education. A doctor is the right person to diagnose and treat your skin.