Ablative Laser · Resurfacing · Collagen Remodeling
CO2 Fractional Laser
How this page was made
This page was written with AI assistance and reviewed against the sources listed under References below. It is general information only, not medical advice. See our full disclaimer for how SHEA creates and reviews treatment information.
01
What it is
Fractional CO2 laser is an ablative resurfacing treatment. CO2 laser energy is absorbed by water in the skin and removes microscopic columns of tissue while leaving areas of surrounding skin untreated. The treatment also creates thermal injury around those columns, followed by wound healing and collagen remodeling.
The word fractional matters. Traditional fully ablative CO2 resurfacing removes the surface across the entire treated area, while fractional treatment creates separated microscopic treatment zones. This allows untreated skin between those zones to contribute to healing, although fractional CO2 still involves more visible recovery than non-ablative treatments.
02
Why people consider it
- Atrophic (indented) acne scars
- Uneven or rough skin texture
- Wrinkles and other signs of photoaged skin
- They are comparing a more intensive resurfacing treatment with treatments that generally involve less recovery
03
What the experience is like
Anesthetic methods vary according to the treatment area, device settings, and clinic protocol. During treatment, the laser is applied across the selected area in a controlled pattern.
Redness, swelling, crusting, and peeling can occur during recovery. How noticeable these are, and how long they last, depends partly on treatment density, energy settings, treatment area, and individual skin response.
Skin may remain pink or sensitive after the initial surface healing. Pigment changes are also possible, which makes post-treatment sun protection particularly important. More than one session may be recommended for some concerns, especially acne scarring.
04
Limitations & considerations
Post-inflammatory hyperpigmentation
Post-inflammatory hyperpigmentation (PIH) is an important consideration with fractional CO2 resurfacing, particularly in darker skin phototypes. In one small study of nine Chinese participants with Fitzpatrick skin types III and IV, PIH was observed in 55.5% at one month and 11.1% at six months after a single full-face treatment. Those figures come from one specific device, protocol, and very small study, so they should not be treated as a general PIH rate for every Asian patient or every fractional CO2 treatment.
- Darker skin phototypes have a greater tendency to develop pigment changes after fractional resurfacing, but risk varies with the individual, device, treatment settings, and protocol
- Older practice commonly involved delaying ablative laser procedures for months after oral isotretinoin. More recent fractional CO2 research has challenged a universal waiting period, including studies in people treated concurrently with isotretinoin. Current or recent isotretinoin use should still be disclosed so the treating clinician can assess the individual situation
- CO2 facial resurfacing can reactivate herpes simplex. If you have a history of cold sores, tell the clinician before treatment so they can decide whether antiviral prophylaxis is appropriate
- A history of poor wound healing, keloids, or hypertrophic scars should be discussed before treatment
- Possible complications include prolonged redness, pigment changes, infection, acne-like eruptions, and scarring. Fractional treatment reduces some of the risks associated with traditional full-field ablative resurfacing but does not eliminate them
- No specific degree of scar, wrinkle, or texture improvement can be guaranteed
Evidence note
A randomized controlled trial of 13 participants with atrophic acne scars compared three monthly fractional CO2 treatments with untreated control areas on the same participants. Blinded physician assessment found improvement in scar texture and atrophy through six months. Participants generally described the improvement as mild to moderate. The study was small, and one author received a research grant and loan of the fractional CO2 laser from the device manufacturer.
A separate study evaluated a single full-face fractional CO2 treatment in nine Chinese participants with Fitzpatrick skin types III and IV. It reported statistically significant improvement in several measured concerns, including texture, wrinkles, enlarged pores, and acne scars. PIH occurred in 55.5% at one month and 11.1% at six months. Because this involved only nine participants and one specific device and protocol, the findings should not be generalized into an expected result or complication rate for all Asian skin. Henry H. Chan, one of the study authors, disclosed being a stockholder of Solta Medical, the manufacturer of the Fraxel Re:pair system studied.
The traditional recommendation to postpone ablative laser treatment for six months after isotretinoin has also been questioned by newer evidence. A 2024 randomized split-face trial found better acne-scar scores with fractional ablative CO2 performed concurrently with isotretinoin than with treatment delayed until six months after isotretinoin cessation. A 2025 prospective study in Thai participants with Fitzpatrick skin type III or higher likewise found no greater overall post-laser erythema or edema in participants receiving isotretinoin concurrently. These findings apply to the studied protocols and populations and do not mean that isotretinoin can be ignored during treatment planning.
References
Peer-reviewed literature.
1. Hedelund L, Haak CS, Togsverd-Bo K, Bogh MK, Bjerring P, Haedersdal M. Fractional CO2 laser resurfacing for atrophic acne scars: a randomized controlled trial with blinded response evaluation. Lasers in Surgery and Medicine, 2012;44(6):447–452.
Peer-reviewed · RCT (n=13) · Manufacturer grant/equipment loan to one author
2. Chan NPY, Ho SGY, Yeung CK, Shek SYN, Chan HH. Fractional ablative carbon dioxide laser resurfacing for skin rejuvenation and acne scars in Asians. Lasers in Surgery and Medicine, 2010;42(9):775–783.
Peer-reviewed · Clinical study (n=9) · Fitzpatrick III–IV · Author stock ownership disclosed
3. Taleb E, Gallo ES, Salameh F, Koren A, Shehadeh W, Artzi O. Fractional ablative CO2 laser and oral isotretinoin: a prospective randomized controlled split-face trial comparing concurrent versus delayed laser treatment for acne scars. Lasers in Surgery and Medicine, 2024;56(1):54–61.
Peer-reviewed · Randomized split-face trial · Concurrent vs delayed isotretinoin
4. Rujirawan P, Charoenchaipiyakul K, Krithin S, Washrawirul C, Kumtornrut C. Ablative Fractional CO2 Laser Treatment With and Without Oral Isotretinoin: A Study on Side Effects and Acne Scars Improvement in Southeast Asians. Lasers in Surgery and Medicine, 2025;57(8):678–684.
Peer-reviewed · Prospective study · 50 enrolled, 45 completed · Fitzpatrick III or higher
5. Beeson WH, Rachel JD. Valacyclovir prophylaxis for herpes simplex virus infection or infection recurrence following laser skin resurfacing. Dermatologic Surgery, 2002.
Peer-reviewed · Clinical study · HSV prophylaxis after facial laser resurfacing
6. Metelitsa AI, Alster TS. Fractionated laser skin resurfacing treatment complications: a review. Dermatologic Surgery, 2010.
Peer-reviewed · Complications review · No significant commercial interest reported