Laser treatment for acne scars: results and risks

Laser treatment for acne scars uses focused light to damage the scarred skin in a controlled way, so the skin heals with new collagen, the protein that gives skin its support. As the skin heals, sunken scars become shallower and the surface looks smoother. The American Academy of Dermatology (AAD) says dermatologists now use lasers for many kinds of scars. It also describes the limit: with laser treatment, "you're replacing one scar with another less-noticeable scar." This guide covers the kinds of lasers, what studies found, the recovery, the risks and the questions to ask. For every other option, see acne scar treatment.

Lasers treat scars, meaning dents and raised bumps in the skin. Flat red or brown marks left by pimples are a separate problem that usually fades with time; see dark marks after pimples.

How a laser treats acne scars

The AAD's acne scar page says: "Dermatologists use lasers to resurface skin with acne scars. As your skin heals after laser resurfacing, it produces collagen and elastin, which can diminish the appearance of scars." Elastin is a protein that lets skin stretch and return to shape. The AAD says a dermatologist may also use a laser "to contour skin around acne scars," smoothing the edges of a dent.

Lasers for acne scars fall into three groups, explained in a 2018 review of 59 studies in the journal Scars, Burns and Healing:

Type	What it does	Pros and cons
Ablative laser	Removes the top layer of skin and part of the layer below	Strongest results, with more pain, longer recovery and more risk of color changes
Fractional ablative laser (for example fractional CO2)	Removes skin in tiny columns and leaves the skin between them untouched	Faster recovery than full ablative lasers
Non-ablative laser	Heats the deeper layer and leaves the surface in place	Safer and less downtime, with smaller results

"Fractional" means the laser treats a fraction of the skin at a time, in a pattern of tiny dots. The skin between the dots helps the treated areas heal faster.

Dermatologists also use other devices on scars. The AAD's general scar page says lasers and pulsed-dye light can lessen a scar's color, such as redness, and it shows a raised scar that became less noticeable after two pulsed-dye laser treatments. Radiofrequency devices use electrical energy to heat the skin. The AAD says radiofrequency microneedling "is safe for all skin tones," and that some small studies suggest it can give results like a laser with less downtime.

What the evidence shows

There are many studies of lasers for acne scars, and most are small. Here is what the main reviews and guidelines say.

• A 2016 Cochrane review. This type of review pools trials to judge how strong the evidence is. It found "a lack of high-quality evidence" for every acne scar treatment. In one trial of 64 people, fractional laser was more likely than a non-fractional, non-ablative laser to give scar improvement that people noticed themselves at 24 weeks. The review put that evidence in the lowest of its four quality grades.
• The 2018 review in Scars, Burns and Healing. It found fractional CO2 laser had the most studies, 20 in all. "Rolling and boxcar scars were found to respond the best while ice-pick scars responded the least." It concluded that ablative lasers seem to give the largest improvement, with "significant pain and downtime" and a risk of lasting changes in skin color.
• NICE, the UK body that writes treatment guidelines. For severe scarring that persists a year after acne clears, it advises referral to a dermatologist-led team and says to "consider CO2 laser treatment (alone or after a session of punch elevation) or glycolic acid peel." Punch elevation is a minor scar surgery for deep scars; the AAD describes scar surgery in which the dermatologist "surgically lifts the scar from the underlying tissue." NICE's committee said there was evidence that these options showed some success in improving the appearance of scars.
• A 2022 international consensus. A panel of 24 dermatologists and plastic surgeons from 12 countries agreed that energy devices, lasers included, are "a first-line treatment for a variety of acne scar types," meaning a first choice. A consensus is expert opinion, a weaker form of evidence than a trial.

The type of scar matters. The 2018 review explains that ice pick scars reach down into the lower layer of the skin or the fat beneath it, and "are likely deeper than the depth that can be reached with conventional lasers." For those, dermatologists often add another treatment. The guide types of acne scars explains the types.

Limits the AAD names

The AAD's page on laser treatment for scars lists ten things to know. These are the ones about results:

• "When you have laser scar treatment, you're replacing one scar with another less-noticeable scar."
• "Your results depend largely on the skills of the person performing the laser treatment."
• "You may need more than one laser treatment." The AAD says this is often necessary with non-ablative lasers, which have no downtime.
• "It can take months to see the results from laser scar treatment, and you may notice little improvement at first."
• Treatment plans often combine methods. The AAD's example is a laser for deep acne scars plus a filler.

Side effects and risks

The main risks are pain, recovery time and changes in skin color. The Cochrane review found that in the trials that recorded pain, every participant reported it. The 2018 review found that aggressive laser settings caused dark patches in 55 to 100 percent of patients in one study, and that lower settings, sun avoidance and sunscreen lowered the risk.

The AAD adds three warnings:

• A tan or sunburn stops treatment. "If you show up for laser treatment with a tan or sunburn, your dermatologist cannot treat you. Using a laser could cause a serious burn or discolor your skin."
• Sun after treatment can scar. "If the sun's harmful rays hit your treated skin, you can develop another scar."
• Training matters. When the person using the laser lacks medical training, the AAD says, "it can even be dangerous."

Lasers and darker skin

Darker skin has more melanin, the pigment that gives skin its color, and the risk of dark or light patches after treatment is a common concern. The 2018 review says radiofrequency energy, unlike lasers, "is not absorbed by melanin," which may make it safer for people with dark skin. The 2022 consensus included advice on acne scar treatment in skin of color. If you have brown or black skin, ask how many people with your skin tone the dermatologist has treated with the chosen device. The guide acne on darker skin covers related care.

How to prepare

The AAD says "a medical consultation is crucial before any laser treatment," and that if someone offers treatment before a consultation, you should leave and find another provider. Tell the dermatologist if you get cold sores, have diabetes or another medical condition, smoke, or take any medicines or supplements. The AAD's acne scar page also asks you to list every acne treatment you have used in the last two years, because some scar treatments cause side effects during or soon after certain acne medicines.

Before treatment, the AAD says dermatologists recommend that patients:

• Quit smoking for at least 2 weeks.
• Stop vitamin E, aspirin and other medicines and supplements that can delay healing, as your doctor directs.
• Stop skin care products that contain a retinoid or glycolic acid for 2 to 4 weeks. See tretinoin for acne scars for how this affects a retinoid routine.
• Take medicine to prevent cold sores, if you get them.
• Avoid the sun, tanning beds and sunlamps.

Recovery and aftercare

Recovery depends on the laser. Non-ablative lasers have no downtime, the AAD says. Ablative lasers need more healing time. After any laser, the AAD's aftercare page says:

• Follow your dermatologist's instructions and use the products they recommend.
• Apply sunscreen every day to the treated skin: broad-spectrum, water-resistant, SPF 30 or higher.
• Avoid spending time outdoors during the day "for 6 to 8 weeks," even on cloudy or cool days.
• Expect some swelling or discoloration, which "typically goes away in a few days."
• Keep treating acne, because "new acne breakouts could cause new acne scars."

Cost and insurance

The AAD says insurers "consider laser treatments cosmetic treatments," and that health insurance "generally does not cover the cost of cosmetic treatments." Its acne scar page says the same of all acne scar treatment. This guide found no independent medical source that lists laser prices, and the cost depends on the laser, the clinic and the number of sessions. Ask for the total cost of the full series at the consultation.

Questions to ask the dermatologist

• Which type of laser do you recommend for my scars, and why?
• How many sessions will I need, and how far apart?
• How much downtime should I plan for after each session?
• What is my risk of dark or light patches with my skin tone?
• Would another treatment, such as subcision or microneedling, help more for my scar type?
• What is the total cost?

When to see a dermatologist

See a board-certified dermatologist when scars bother you and your acne is under control. The AAD says scar treatment usually starts once acne is under control. Skinli gives general education and is not a doctor. The free Skinli acne plan can help with the acne that comes first.