CO2 laser resurfacing

What it is

• Each pass vaporizes a thin layer and heats the collagen beneath, which shrinks and is rebuilt over the following months (PMID 9801677, PMID 9464299).
• Fully ablative resurfacing treats the whole surface; healing takes longer, and redness can last months (PMID 8629842, PMID 9537005).
• Fractional resurfacing treats tiny columns and leaves bridges of normal skin, so the surface heals in days (PMID 15216537, PMID 17311274). Raising the energy deepens the columns; raising the density treats more of the surface (PMID 19951188).

Where it came from

• Pulsed CO2 lasers were reported in the mid-1990s, with large improvements in lines around the mouth and eyes and new collagen seen on biopsy (PMID 8629842, PMID 8823015, PMID 9464299).
• The cost showed in large series: redness lasting months, temporary darkening, infections and, later, lasting lightening of treated skin (PMID 9537005, PMID 10071310).
• In 2004 fractional treatment was introduced, and in 2007 the first fractional CO2 laser: the skin surface healed within about a day between the treated columns (PMID 15216537, PMID 17311274). Complication rates fell well below those of fully ablative treatment (PMID 20100273).
• In 2025 expert panels published consensus guidance on both fractional and fully ablative CO2, covering who should not be treated, preventive medicines, aftercare and complications (PMID 39434507, PMID 40495549).

Who it suits

• Fine and moderate wrinkles around the mouth and eyes, and sun-damaged facial skin (PMID 8823015, PMID 8629842). Lines made by muscle movement, such as frown lines, respond least (PMID 8823015).
• Crepey upper eyelid skin and lines around the eyes, sometimes in place of or before eyelid surgery (PMID 15056134, PMID 34618888).
• Lighter skin types carry the lowest pigment risk; darker skin types (IV to VI) have more darkening after treatment, and settings are adjusted for them (PMID 41968192, PMID 39434507).
• Fully ablative treatment is not advised while taking isotretinoin for acne; the evidence does not support delaying fractional treatment (PMID 28658462).
• People with past cold sores need antiviral medicine around treatment (PMID 10193975).

How it is done

• On a 2025 expert panel, nearly all used numbing cream and most used nerve blocks; nearly all gave antibacterial and antiviral medicine to prevent infection (PMID 39434507).
• The surgeon sets energy and density for the depth wanted and adjusts settings for darker skin (PMID 19951188, PMID 39434507).
• Several gentler fractional sessions gave better results, higher satisfaction and shorter downtime than one aggressive session (PMID 37464979).
• Around the mouth, laser and dermabrasion gave similar results; dermabrasion healed faster, and laser gave slightly more improvement in one study (PMID 10871933, PMID 11083571).

Results and how long they last

• In one early fully ablative series, lines around the eyes and mouth improved by about 90% on average (PMID 8823015); full-face treatment improved wrinkle scores by about 45% in another (PMID 18645090).
• Improvement held at one and two years, and biopsies showed continued repair of sun damage (PMID 9464299, PMID 10071310). In Asian skin, fractional results held at five years (PMID 25400224).
• Fractional CO2 improved wrinkles and folds more than two non-ablative fractional lasers in a large series (PMID 28032173). A meta-analysis of small randomized trials found no difference in results between ablative and non-ablative lasers (PMID 35107665).
• Lower eyelid treatment satisfied nearly all patients in a large series (PMID 33481534). Fractional CO2 before upper blepharoplasty raised collagen in the eyelid skin, and lines kept improving to six months (PMID 34618888).

Risks and how surgeons lower them

• Fully ablative: in a large series every patient had redness, lasting a mean of 4.5 months; temporary darkening affected about 1 in 3, more in darker skin; acne flares, small white cysts or rashes about 1 in 10; cold sores about 1 in 14; scarring and lasting lightening under 1 in 100 (PMID 9537005).
• Lasting lightening (hypopigmentation) is the main late side effect, linked to the amount of sun damage before treatment (PMID 10071310). It appeared in about 1 in 8 to 1 in 16 patients in other series (PMID 18645090, PMID 14726880).
• Infection: about 1 in 25 fully ablative procedures, between days 2 and 10, more after full-face treatment and airtight dressings (PMID 9236870). Antiviral medicine kept 9 in 10 patients free of cold sores, though about 1 in 3 with past cold sores still had one (PMID 10193975).
• Fractional: complications are much less common, but serious ones occur, mostly on sensitive areas such as the neck and in darker skin (PMID 20100273, PMID 27115980). About 1 in 15 fractional CO2 patients had a complication in a large series, and all resolved (PMID 28032173).
• Darker skin: darkening is the most frequent complication, especially in types IV to VI; fully ablative CO2 and erbium carried the highest risks of scarring and infection (PMID 41968192).
• Eyelids: after lower eyelid treatment, darkening affected about 1 in 10, scars were small and rare, and no lid turned out (PMID 33481534). Combined with lower blepharoplasty, about 1 in 60 had a lid pulled down that needed surgery (PMID 35947796).

Recovery

• After a single fully ablative pass, the skin surface healed in about five to six days; redness lasted about a month, and nearly half had darkening that faded over about three months (PMID 12534517).
• After multi-pass fully ablative treatment, redness lasted a mean of 4.5 months (PMID 9537005).
• New skin grows from hair follicles; a covering dressing sped the start of healing (PMID 10839420).
• Downtime after fractional treatment was about four days after gentler settings and seven after one aggressive session (PMID 37464979).

With a facelift

• In one series, 1 of 10 patients whose whole lifted (undermined) facelift flap was lasered lost full-thickness skin at the flap tip; laser over skin that was not lifted did not raise complications (PMID 11910322).
• Pooled studies found full-thickness skin loss in about 1 in 10,000 and superficial skin slough in about 1 in 500 when laser and facelift were combined; full energy over lifted skin went with more slough (PMID 41063540).
• Lower eyelid CO2 is often done in the same session as lower blepharoplasty (PMID 33481534, PMID 35947796).

Questions to ask a surgeon

• Fractional or fully ablative for my skin, and why? (PMID 35107665)
• How long will I be red, and when can I go out? (PMID 9537005)
• What is the risk of darkening or lightening for my skin type? (PMID 41968192)
• Will I take antiviral and antibiotic medicine? (PMID 39434507)
• If I am having a facelift too, how will you treat the lifted skin? (PMID 41063540)

Open questions

• Ablative or non-ablative: randomized trials found no difference in results (PMID 35107665); a broader review found fewer lasting complications with ablative lasers (PMID 33084193).
• Lines around the mouth: a review proposes combining injections, microneedling and lasers (PMID 34838938).
• Skin of color: one recent study recorded no darkening in types I to IV with no data for V and VI (PMID 42121348); darkening remains the most reported complication in IV to VI (PMID 41968192).
• Standards rest on expert consensus (PMID 39434507, PMID 40495549).
• Healing aids: nanofat and a growth factor were tested after CO2 with no difference between them (PMID 41890322).

Terms

• Ablative laser: removes (vaporizes) the outer skin layers (PMID 33084193).
• Fully ablative (confluent) resurfacing: laser passes cover the whole treated surface (PMID 40495549).
• Fractional resurfacing: narrow columns of injury with untreated skin between them, which speeds healing (PMID 15216537, PMID 17311274).
• Microscopic treatment zone: one column of fractional injury (PMID 15216537).
• Pass: one complete sweep of the laser over an area; more passes go deeper (PMID 9801677).
• Reepithelialization: new surface skin covering the wound (PMID 10839420).
• Postinflammatory hyperpigmentation: temporary darkening during healing (PMID 9537005).
• Hypopigmentation: lasting lightening of treated skin (PMID 10071310).
• Dermatochalasis: excess upper eyelid skin (PMID 15056134).
• Fitzpatrick skin type: I to VI scale of skin color; higher types carry more pigment risk after laser (PMID 41968192).

Papers