Treating acne scars effectively depends on what type of scar you’re dealing with and how deep it goes. No single treatment works for all scars, but most people see noticeable improvement within three to six months using the right approach, and sometimes a combination of approaches works best. The key is matching the treatment to the scar type.
First, Know What You’re Actually Treating
Many people searching for acne scar treatments are actually dealing with post-inflammatory hyperpigmentation (PIH), not true scars. PIH shows up as flat spots of discoloration, ranging from pink and red to brown or purple, left behind after a breakout heals. It’s sometimes called “pseudo scarring” because it doesn’t damage the skin’s structure. These marks fade on their own over time, though they can linger for months.
True acne scars involve structural changes to the skin. They fall into a few categories:
- Ice pick scars: Deep, narrow holes that look like the skin was punctured with a sharp instrument.
- Boxcar scars: Wider depressions with sharply defined edges, like a shallow box pressed into the skin.
- Rolling scars: Broad, wave-like depressions caused by bands of scar tissue pulling the skin surface downward.
- Hypertrophic or keloid scars: Raised tissue where the body overproduced collagen during healing.
If your marks are flat and just darker than surrounding skin, you likely have PIH and can focus on gentler topical treatments or light-based therapies. If the texture of your skin has changed, you’re working with true scarring and will benefit from the more intensive options below.
Topical Retinoids for Mild Scarring
Retinoids (vitamin A derivatives available by prescription or over the counter) are the most accessible starting point. They work by speeding up skin cell turnover and gradually stimulating the deeper layers of skin to produce fresh collagen. This process is slow. It takes roughly six months of consistent use before retinoids meaningfully affect scar depth, because the remodeling process in the deeper skin layers happens on a longer timeline than surface-level changes.
In one clinical study, 56% of participants using a prescription-strength retinoid gel showed a one- to two-grade improvement in their atrophic scars after 24 weeks. Another study found a 21.7% decrease in visible scarring at 24 weeks, increasing to 26.9% at 48 weeks. These aren’t dramatic before-and-after transformations, but for mild, shallow scarring, retinoids can produce a real and compounding improvement over time. They’re also a good complement to in-office procedures.
Microneedling
Microneedling uses a device studded with fine steel needles (typically 1.5 to 2 mm long) that puncture the skin’s surface in a controlled pattern. The idea is counterintuitive: you’re creating tiny injuries to trigger the body’s wound-healing response, which breaks apart the dense, disorganized collagen bundles that form scar tissue and replaces them with new collagen and elastin. For deeper scars, needles up to 2.5 to 3 mm may be used, though this is less common.
Microneedling works well for boxcar and rolling scars, with noticeable improvement typically visible within three to six months. Most treatment plans involve multiple sessions spaced several weeks apart. A numbing cream is applied beforehand. The procedure itself causes redness and mild swelling that resolves within a day or two for most people.
Laser Resurfacing
Lasers are one of the most effective tools for acne scars, and they come in two main categories. Ablative lasers (like fractional CO2) vaporize tiny columns of damaged skin, creating micro-wounds that force the body to rebuild with fresh collagen. Non-ablative lasers (like the 1410 nm diode) work differently: they heat columns of tissue beneath the surface without breaking through the outer layer of skin, triggering collagen remodeling from below while leaving the surface intact.
You might assume the more aggressive option would deliver better results, but clinical evidence suggests otherwise. In a head-to-head study where patients received three monthly sessions of each type on opposite sides of the face, both lasers produced statistically significant improvement in scar appearance. The difference between the two was not significant for any scar subtype. Collagen production was slightly higher on the ablative side (39.7% vs. 37.8%), but this gap wasn’t meaningful.
The practical difference is in recovery. Ablative lasers cause more redness, swelling, and peeling, with longer downtime. Non-ablative lasers are gentler on the surface, meaning less visible healing. Three sessions spaced one month apart is a common protocol for both. Visible improvement often takes three to six months to fully develop, and complete healing can stretch to a year for deeper scars.
TCA CROSS for Ice Pick Scars
Ice pick scars are notoriously stubborn because they’re so narrow and deep. A technique called TCA CROSS (Chemical Reconstruction of Skin Scars) targets them specifically. A dermatologist dips a fine, blunt-tipped instrument (often something as simple as a toothpick) into a high-concentration trichloroacetic acid solution (70 to 100%) and applies it directly to the base of each individual scar. The acid causes a controlled chemical injury at the bottom of the scar, and as the tissue heals, new collagen fills in the depression from below.
Each application takes only about 10 seconds per scar, just until the surface turns white (a sign called “frosting”). Multiple sessions are usually needed, and the procedure targets one scar at a time rather than treating large areas of skin. This precision is what makes it effective for the type of scarring that lasers and microneedling struggle to reach.
Subcision for Rolling Scars
Rolling scars look wavy because fibrous bands of tissue beneath the skin are pulling the surface downward. Subcision addresses this directly: a needle is inserted beneath the scar to physically sever those tethering bands, releasing the skin so it can sit flat again. The small pocket of space created underneath also fills with blood, which eventually becomes new connective tissue that adds volume.
This approach works best for rolling scars specifically. Deeper boxcar and ice pick scars don’t respond as well. In one study of 45 patients who received subcision combined with microneedling, 95.6% showed improvement by at least one grade, with only mild redness, swelling, and soreness lasting one to two days. Subcision also pairs well with fractional CO2 laser and platelet-rich plasma (PRP) injections. Larger, more noticeable rolling scars tend to improve more dramatically than small or shallow ones.
Combining Treatments
Because different scar types respond to different treatments, many dermatologists use a combination approach. A common strategy might involve subcision to release tethered rolling scars, TCA CROSS to raise the floor of ice pick scars, and fractional laser to smooth boxcar scars and improve overall texture. Microneedling can be layered in between more aggressive sessions to keep collagen remodeling active.
This isn’t about doing everything at once. A treatment plan is usually staged over several months, with each procedure targeting a different aspect of the scarring. The total timeline from first treatment to final results often spans six months to a year.
Special Considerations for Darker Skin
People with darker skin tones (Fitzpatrick skin types IV through VI) face additional risks when treating acne scars. The same inflammation that triggers healing can also trigger the skin to release excess melanin, creating new dark spots, effectively trading one cosmetic problem for another. In more severe cases, aggressive treatments can cause keloid scarring, where scar tissue continues growing beyond the boundaries of the original wound.
Harsher treatments are more likely to cause this kind of rebound damage. Gentle products and conservative treatment settings reduce the risk. Lasers, chemical peels, and resurfacing procedures can still be effective for darker skin, but the settings and protocols need to be adjusted by someone experienced with these skin types. If done incorrectly, these procedures can worsen both scarring and hyperpigmentation. This is one situation where the expertise of the person performing the procedure matters as much as the procedure itself.
Realistic Expectations
No treatment erases acne scars completely. The goal is significant improvement in depth, texture, and visibility. For most people, boxcar and rolling scars respond well to microneedling or fractional laser, with noticeable improvement within three to six months. Ice pick scars are harder to treat and typically require multiple targeted sessions over several months before results become visible. Hypertrophic and keloid scars can be reduced with corticosteroid injections or laser therapy, with improvement appearing within three to six months and full results taking up to a year.
Patience is built into the biology. Collagen remodeling happens gradually, and the skin you see three months after a procedure is still actively healing and improving. Many people continue to see gains for six to twelve months after their last session.