Chemical peels for acne scars: which peel, risks

A chemical peel is an acid solution that a dermatologist puts on the skin to remove its outer layers in a controlled way. As the skin heals, it makes new collagen and elastin, two proteins that give skin support and stretch. The American Academy of Dermatology (AAD) says "when the skin has more of both, depressed acne scars tend to be less noticeable." Peels come in many strengths, and one technique places a strong acid inside each scar. This guide covers which peels dermatologists use for acne scars, what studies found for each scar type, the healing time and the risks. For every other option, see acne scar treatment.

Dermatologists also use peels for flat discoloration, which is a separate problem from scars. If your marks are flat and only the color has changed, start with dark marks after pimples and hyperpigmentation.

How peels are grouped

The AAD groups peels by depth, and depth decides both results and recovery:

• Refreshing or "lunchtime" peels affect the top layer. They heal in days and often need 3 to 5 sessions.
• Medium peels go deeper and need a week or two to heal.
• Deep peels go deepest. The AAD says you receive general anesthesia, which puts you to sleep, and the peel "must be performed in a surgical setting." A person can have only one deep peel.

A 2017 review in the journal Scars, Burns and Healing adds that deep peels "require sedation," medicine that makes you sleepy or unconscious, "and have the potential to cause cardiotoxicity," meaning harm to the heart. The AAD explains that with a deep peel, the skin is treated one small section at a time to limit the effects on the heart and lungs.

For acne scars, the AAD's scar page says a dermatologist chooses the strength: "Peels are available in strengths ranging from mild to strong. Your dermatologist will determine which strength best meets your needs. Mild and medium peels often require more than one treatment session. For example, if you have a mild peel, you may need 3 to 5 treatments, which are given every 2 to 4 weeks."

Peels used for acne scars

The 2017 review looked at 12 studies of peels for acne scars, most of them in people with ice pick scars. These are the main types:

Peel	How it is used	What the studies found
Glycolic acid	Whole-face peel, often every 2 weeks	Modest gains on ice pick and boxcar scars; no change in rolling scars in one study
Salicylic acid with mandelic acid	Whole-face peel	Compared with glycolic acid in one study; the numbers are below
Trichloroacetic acid (TCA), 20 percent	Whole-face peel	In one study of 25 people, 28 percent had marked improvement and all improved to some degree
TCA CROSS	A strong TCA solution placed into the base of each scar with a fine tool	Excellent improvement in most patients with ice pick scars in several studies
Phenol	Deep peel under sedation	Large improvement in small studies; the most risk

NICE, the UK body that writes treatment guidelines, lists one peel by name. For severe scarring that persists a year after acne clears, it says a specialist team should "consider CO2 laser treatment (alone or after a session of punch elevation) or glycolic acid peel."

What the studies found for each scar type

Ice pick scars. These deep, narrow holes responded best to TCA CROSS. In one study in the 2017 review, 30 people with mainly ice pick scars had treatment every two weeks for four sessions. Excellent improvement, meaning more than 70 percent, was seen in 73.3 percent of them. In another study of 53 people with several types of sunken scars, TCA CROSS gave 66 percent of them more than 50 percent improvement at three months, and 81.1 percent said they were satisfied with the treatment. The review concluded that "ice pick scars seem to be particularly responsive to treatment with chemical peels, especially when treated with TCA CROSS."

Boxcar scars. In a study of 44 people who had six glycolic acid or salicylic-mandelic peels two weeks apart, boxcar scars improved by 20.1 percent with glycolic acid and 23.3 percent with the salicylic-mandelic peel. Ice pick scars in the same study improved by 10.4 and 13.2 percent. Deep boxcar scars resist surface treatments, the review says.

Rolling scars. In the same study, "there was no change in rolling scars with either of the two agents." Rolling scars are pulled down by bands of tissue under the skin, so they usually need treatment below the surface, such as subcision.

The evidence has limits. A 2016 Cochrane review, which pools trials to judge how strong the evidence is, found "a lack of high-quality evidence" for every acne scar treatment. In one trial it included, a chemical peel and microneedling gave similar improvement, but the peel caused dark patches in 6 of 12 people, compared with none of 15 after microneedling. In another, 7 of 43 people (16 percent) could not tolerate the peel. A 2018 review describes a 28-person trial in which a CO2 laser worked better than TCA CROSS. The guides on laser treatment and microneedling cover those options.

Healing time by depth

The AAD's peel page gives this timeline:

Peel depth	Healing time	What to expect at home
Refreshing or lunchtime	1 to 7 days	Redness, then scaling for 3 to 7 days. Lotion until healed, then daily sunscreen. Makeup usually right away
Medium	7 to 14 days	Redness and swelling that worsens for 48 hours, possible blisters, crusting. Daily soaks and ointment, antiviral medicine for 10 to 14 days, no sun until healed. Makeup after 5 to 7 days
Deep	14 to 21 days	Bandages, several soaks a day, antiviral medicine, and "total sun avoidance for 3 to 6 months." Makeup after at least 14 days

The AAD says a deep peel "requires recuperation at home for 2 to 3 weeks."

Side effects and risks

The AAD says that with an experienced doctor, "side effects tend to be mild." Possible side effects include:

• "Persistent redness that may last for months."
• "Temporary darkening of the skin."
• "Lighter skin color (medium and deep peels)."
• Scarring, which the AAD says is rare when a dermatologist does the peel.

The AAD says the risk of infection or scarring rises if you do not protect your skin from the sun, do not care for the wound as told, scratch or pick at scabs, wear makeup before the skin heals, or use a tanning bed. It also says: "If your skin dries and cracks, it can scar."

Darker skin. The AAD says people with skin of color can safely have a peel, "but they should see a dermatologist who has expertise using chemical peels to treat darker skin tones. Without this knowledge, people who have skin of color (i.e., African American, Asian, Latino) can develop permanent pigment problems." The guide dark spots on darker skin explains why darker skin forms dark patches more easily.

Before a peel

The AAD's acne scar page says your dermatologist may give you "pre-peel priming" instructions to follow at home for 2 to 4 weeks. This "can include taking an antiviral medication or applying a retinoid," and it helps results and reduces side effects. The 2017 review adds that tretinoin is often used before medium and deep peels so the acid goes in evenly and dark patches are less likely. See tretinoin for acne scars.

Tell your dermatologist, the AAD says, if you are taking or have ever taken isotretinoin, a prescription pill for severe acne; about all other medicines, herbs and supplements; if you get cold sores; if your skin scars easily; and about past cosmetic treatments. Protect your skin from the sun before the peel, too.

The AAD suggests asking:

• Will a board-certified dermatologist do the peel?
• How many peels has the doctor done on people with my skin coloring?
• What results can I expect, and what are the side effects?
• Will I have downtime?
• How much will it cost?

Why strong peels at home are risky

In July 2024, the FDA warned consumers "not to purchase or use certain chemical peel skin products without appropriate professional supervision due to risk of serious skin injuries." It said many products sold online and in beauty stores contain trichloroacetic, glycolic, salicylic and lactic acid "in varying concentrations that are too high to be used safely at home." These products "may cause severe chemical burns, pain, swelling, infection, skin color changes, and disfiguring scars." The FDA added that it "has not approved any chemical peel products." The AAD repeats the advice: buy and use a chemical peel only under the supervision of a licensed, trained provider such as a dermatologist.

Cost and insurance

The AAD says "chemical peels are considered a cosmetic treatment. Insurance does not cover the cost of cosmetic treatments." Prices depend on the peel and the number of sessions, and this guide found no independent medical source that lists them. Ask for the full cost at the consultation.

When to see a dermatologist

See a dermatologist once your acne is under control and your scars bother you. The AAD says scar treatment usually begins after acne is controlled, because new breakouts can cause new scars. Skinli gives general education and is not a doctor. The free Skinli acne plan helps with active acne. To find out which scar type you have before the visit, read types of acne scars.