Written by Alexander Bonato, MD, board-certified in Internal Medicine by the American Board of Internal Medicine (ABIM) · Updated November 13, 2026
The short answer: Fractional CO2 laser resurfacing treats a grid of microscopic columns of skin to improve wrinkles, uneven texture, sun damage and atrophic scars such as acne scars. Afterward, skin typically feels like a sunburn, with crusting and flaking for up to about two weeks. Redness or pinkness often lasts about 1 to 2 weeks and can last longer after deeper settings. Results depend on the settings, your skin and the concern being treated, and no single study predicts every patient’s outcome.
At Bonato MD Aesthetics in Medford, candidacy is assessed individually. Skin tone, medications, healing history, recent sun exposure and other treatments all affect whether we proceed, modify the plan or recommend waiting. To see how we approach it, visit our CO2 laser resurfacing in Medford page.
I've hit a golf ball off a roof. I've hit one onto an actual road, the kind with moving cars on it. By hole four on one particularly bad day, I'd left enough divots that the fairway looked like something had recently grazed through it. At this point I only play courses that already have a few problems. Nothing I do is going to be what ruins them.
That's not really a golf story. It's a story about what happens when you apply a lot of force without quite enough precision. It also happens to be the exact problem a fractional CO2 laser was built to solve. I'm a physician board-certified in Internal Medicine (American Board of Internal Medicine), practicing aesthetic medicine at Bonato MD Aesthetics in Medford, and fractional CO2 resurfacing has a large body of published research behind it, including many randomized trials, though many of them are small. It's also one where the settings matter more than the power, which is a lesson I clearly never applied to a 7-iron.
This post is the explainer: how the laser works, what the research shows and where its limits are. For candidacy, preparation and booking, our fractional CO2 laser resurfacing service page has the details.
What Fractional CO2 Laser Resurfacing Actually Does
A CO2 laser puts out light at a wavelength, 10,600 nanometers, that water absorbs well (Reference 4). Skin is mostly water, so the energy gets soaked up fast, right at the surface and down into the dermis underneath it. "Fractional" is the important word here. Instead of treating the entire surface at once, the laser fires through a scanner that breaks the beam into an array of tiny columns, each a few hundred microns wide, depending on the device and energy, in a grid pattern across the treatment area (References 4, 5).
Each column vaporizes a small cylinder of tissue and leaves a ring of controlled heat damage around it. The skin between those columns is left intact. That untouched tissue is the reservoir your body uses to heal fast, migrating new cells in from the sides instead of having to rebuild an entire surface from scratch (Reference 4). You leave with a visible pinprick grid and some redness. Then, over the following weeks and months, your skin remodels collagen around those points (Reference 6), which is why texture can keep improving for several months after treatment.
It's the same logic as aerating a lawn. You're not trying to kill the grass. You're poking a controlled pattern of holes in it so it grows back thicker than it started.
What It's Used For
In practice, fractional CO2 resurfacing gets used for a fairly wide range of things:
Wrinkles and fine lines (rhytids), especially the static ones that stick around at rest
Uneven texture and general photoaging from sun damage
Atrophic scars, including acne scars, and, with less certain evidence, raised (hypertrophic) scars
Uneven pigment as part of sun damage
Stretch marks
The evidence behind these uses is not equal. For atrophic acne scars there are pooled analyses of randomized trials (References 2, 7). For wrinkles, this post covers one small randomized trial (Reference 1). For raised scars it is very low certainty (Reference 8), and for stretch marks the studies show improvement, though complete clearance is uncommon (References 9, 10). For individual sun spots, head-to-head trials found other lasers worked better than fractional CO2 (References 11, 12), which is why I describe pigment here as part of sun damage rather than as spot removal. I've got real trial data in hand for two of the items above, wrinkles and acne scars, so let's look at the actual evidence instead of listing indications like a brochure would.
The Science, Simplified: Wrinkles
A 2025 randomized trial in China tested a Lumenis UltraPulse CO2 laser on wrinkles around the eyes (Reference 1). Thirty people enrolled and twenty completed the study. Each person was assigned to one of three energy-and-density settings, and one side of each face also got hydroquinone, a skin-lightening medication, to help prevent darkening. Only that comparison was split-face; both sides received laser.
Only the lower-energy, higher-density setting showed a statistically significant drop in the Fitzpatrick wrinkle score. Ratings by the doctors and patients did not differ significantly between the three settings. Darkening after treatment was less common on the side that used hydroquinone. Follow-up continued for six months after the second treatment.
That supports careful parameter selection. It does not establish one ideal setting for every device, skin type or treatment area. I didn't find any study in this post that used the Phoenix CO2 in our office, so their exact settings don't transfer directly.
The study was small, with only about 3, 11 and 6 people left in the three groups after dropouts, and Lumenis provided part of its funding. These are useful findings, not a prediction of your individual result.
The golf lesson survives: dialed in beats maxed out.
The Science, Simplified: Acne Scars
For acne scars, I'm leaning on pooled analyses of randomized trials rather than any single study (References 2, 7). Here's the part that matters: these analyses mostly compare lasers against other established scar treatments already in use, such as non-ablative lasers and radiofrequency microneedling, not against doing nothing.
Those analyses find that ablative fractional laser, the family CO2 belongs to, improves acne scars somewhat more than non-ablative lasers (Reference 7) and than radiofrequency microneedling (Reference 2), and they report more pain with it (References 2, 7). The 2026 analysis of eight trials (249 patients) also found longer redness, and about four times the risk of darkening, with fractional CO2 compared with radiofrequency microneedling (Reference 2). The trials are small, the summaries I read don't say which lasers were used, and I didn't find one that used our Phoenix CO2. These are abstract-level summaries, not a prediction for any one patient.
If acne-scar texture is your main complaint, the pooled trials suggest CO2 can improve it, and somewhat more than some alternatives. If you're hoping it clearly beats microneedling or other established scar treatments across the board, the evidence doesn't establish that. It's a useful option, but these pooled results do not establish that it is superior, or equivalent, to every alternative. I'd love to tell you this is the one laser to end all lasers. The data won't let me sell you that.
Who's a Good Candidate—and When We Wait
Candidacy depends on your skin, the concern being treated and your ability to follow the preparation and recovery plan. Here is how I approach it at Bonato MD Aesthetics.
Skin Tone Changes the Plan
Expert consensus for facial skin rejuvenation favors lighter skin (Fitzpatrick types I–III) as the best candidates for CO2 resurfacing, and darker skin tones are generally considered more susceptible to darkening afterward (Reference 14). Darkening is usually temporary, though it can take months to fade and can occasionally be lasting (References 1, 17). That consensus comes from a panel of 21 dermatologists and plastic surgeons chosen for their experience with one manufacturer's laser, and several of its authors have ties to that manufacturer, Lumenis. It is expert opinion, not trial data.
In my practice, CO2 resurfacing gives its most predictable results in Fitzpatrick types I–III. Treating types IV–VI is off-label. I consider it case by case, after an individual assessment, with modified settings and a series of gentler sessions, and for many people another treatment is a better fit. A consultation is an assessment, not an automatic promise that we will proceed.
Published pigmentation rates vary considerably across studies because patients, devices, settings and care protocols differ. One 2023 review of 14 studies found darkening after CO2 treatment ranging from 0% to 100%, and it found no clear difference by skin type, though the studies were small, inconsistent and mostly in Fitzpatrick type IV patients (Reference 3). That variation does not mean skin tone is irrelevant or that a percentage from one study predicts your risk.
When We Reschedule
At our practice, we postpone treatment for:
An active infection or cold sore in the treatment area.
Recent sun exposure or tanning within four weeks, or self-tanner within two weeks.
Dermal filler within four weeks or neurotoxin treatment within two weeks.
Isotretinoin use within the past month.
An active acne or rosacea flare that needs to settle first.
Pregnancy or breastfeeding.
These are our scheduling policies. Your individual assessment may lead to a longer wait.
Medications and Healing History Need a Conversation
Tell me about diabetes, keloid scarring, autoimmune disease, previous radiation, poor healing, metal hardware near the treatment area and any other relevant medical history. These findings require assessment; they are not all automatic exclusions.
If you've ever had cold sores, tell me before we schedule. Patients with that history start an antiviral one day before treatment.
Daily prescribed blood thinners are not an automatic exclusion under our practice policy. Keep taking prescribed blood thinners or aspirin as directed. Any change is up to the physician who prescribed them, so please don't stop them on your own to prepare for laser treatment.
If you have used isotretinoin at any point in the past six months, tell us. We generally defer CO2 treatment until at least one month after the last dose, but that is not automatic clearance to proceed. I assess your skin and may recommend waiting longer.
Tell us about any lesion, persistent rash or history of skin cancer in the treatment area before scheduling.
The goal is a treatment plan that fits your skin—not getting everyone through the same checklist.
Where This Fits
If scar texture is your main concern and you want the fuller comparison against another option we offer, our microneedling for acne scars post walks through that alternative in more detail. If your scars are the narrow, deep kind, our ice-pick scars post explains why they behave differently. If you'd rather have less downtime, the 1927 nm thulium laser post covers our gentler 1927 nm option. And if you want to know exactly what the week after this treatment looks like, day by day, that's our CO2 laser recovery post, because it deserves more than a paragraph here. For milder sun damage, my post on TCA chemical peels for photoaging covers another option.
Frequently Asked Questions
Does it hurt?
There's real discomfort, not nothing. Patients in the wrinkle trial rated discomfort 3 to 7 out of 10 after treatment, and most rated it under 4 (Reference 1). Right afterward the skin typically feels like a sunburn. Redness and swelling follow, then crusting and flaking for up to about two weeks, and pinkness can last for one to two weeks (References 14, 17). We apply numbing ointment beforehand, and for deeper treatments I may add injected local anesthesia or a nerve block, all of which I promise is more effective than my golf swing.
How many sessions will I need?
The wrinkle trial used two sessions, three months apart, and one small acne-scar trial used three monthly sessions (References 1, 13). We'll settle on a number based on what we're actually treating, not a fixed package.
Am I a candidate?
A consultation is the right way to find out. Skin tone, medications, healing history, recent sun exposure and previous treatments all affect the decision. Some findings mean waiting, some require a modified plan, and some make another treatment more appropriate. The candidacy section above explains our practice's approach.
Will the results last?
The wrinkle trial discussed here followed patients for six months after their second treatment and reported improvement at that point. That does not establish how long every patient's result will last. New sun damage, acne and ongoing aging can affect the outcome. This resurfaces what's there. It doesn't vaccinate you against time.
How's this different from gentler, "no downtime" lasers?
CO2 is ablative, meaning it actually removes a fraction of the skin's surface in that grid pattern. Gentler, non-ablative lasers, such as our 1927 nm thulium laser, warm the skin in tiny columns without opening the surface, mostly in its upper layers, so there is generally less downtime and a more modest change per session (References 4, 15, 16). In one small imaging study on a volunteer's forearm, higher-energy 1927 nm light became superficially ablative (Reference 15). That study used a different 1927 nm laser than ours, and I didn't find a trial that compares 1927 nm head to head with CO2, so this is a general pattern, not a measured difference. Neither one is the "better" laser in the abstract. They're built for different amounts of change and different amounts of time you're willing to spend recovering.
What about darker skin tones?
Darker skin requires greater caution about pigment changes. At our practice, Fitzpatrick types IV–VI are considered individually, with modified settings and gentler sessions when appropriate. For some patients, another approach is a better fit. Your consultation determines whether CO2 is suitable; skin type alone does not promise eligibility.
CO2 Laser Resurfacing, Start to Finish
Fractional CO2 resurfacing has a large research base and can work well when the settings are dialed in by someone paying attention to more than the power dial. It's not a universal upgrade over every gentler alternative, and it's not right for every skin type. If you're in Medford, Ashland, or Grants Pass and you want to talk through whether it fits what you're actually trying to fix, come in and let's look at it together. Bring your questions and bring your skin history.
Book a free consultation or call 541-243-7546, and we'll figure out together whether CO2 resurfacing is the right tool for you.
Your treatment plan is determined at your consultation with Dr. Bonato.
References
Wu X, Cen Q, Jin J, et al. An Effective and Safe Laser Treatment Strategy of Fractional Carbon Dioxide Laser for Chinese Populations with Periorbital Wrinkles: A Randomized Split-Face Trial. Dermatol Ther (Heidelb). 2025;15(6):1307-1317. https://doi.org/10.1007/s13555-025-01404-3
Argobi Y, et al. Fractional CO2 laser versus micro needling radiofrequency for post acne scarring: a meta-analysis of RCTs. J Cosmet Dermatol. 2026;25:e70765. https://pubmed.ncbi.nlm.nih.gov/41821146/
Bin Dakhil A, Shadid A, Altalhab S. Post-inflammatory hyperpigmentation after carbon dioxide laser: review of prevention and risk factors. Dermatol Rep. 2023;15:9703. https://doi.org/10.4081/dr.2023.9703
Omi T, Numano K. The role of the CO2 laser and fractional CO2 laser in dermatology. Laser Ther. 2014;23(1):49-60. https://doi.org/10.5978/islsm.14-RE-01
Hantash BM, et al. Ex vivo histological characterization of a novel ablative fractional resurfacing device. Lasers Surg Med. 2007;39(2):87-95. https://pubmed.ncbi.nlm.nih.gov/17115384/
Hantash BM, et al. In vivo histological evaluation of a novel ablative fractional resurfacing device. Lasers Surg Med. 2007;39(2):96-107. https://pubmed.ncbi.nlm.nih.gov/17311274/
Li MY, et al. Effectiveness and safety of energy-based devices for acne scars: a network meta-analysis of randomized controlled trials. Facial Plast Surg Aesthet Med. 2023;25(6):521-527. https://pubmed.ncbi.nlm.nih.gov/36946785/
Leszczynski R, da Silva CA, Pinto ACPN, Kuczynski U, da Silva EM. Laser therapy for treating hypertrophic and keloid scars. Cochrane Database Syst Rev. 2022;9:CD011642. https://pubmed.ncbi.nlm.nih.gov/36161591/
Wu TJ, Huang YL, Kang YN, et al. Comparing energy-based devices for striae improvement: a systematic review and network meta-analysis of randomized controlled trials. Dermatol Surg. 2024;50(10):931-938. https://doi.org/10.1097/DSS.0000000000004252
Zhu CK, Mija LA, Koulmi K, et al. A systematic review on treatment outcomes of striae. Dermatol Surg. 2024;50(6):546-552. https://doi.org/10.1097/DSS.0000000000004151
Schoenewolf NL, et al. Laser treatment of solar lentigines on dorsum of hands: QS ruby laser versus ablative CO2 fractional laser, a randomized controlled trial. Eur J Dermatol. 2015;25(2):122-126. https://pubmed.ncbi.nlm.nih.gov/25788397/
Vachiramon V, et al. Comparison of Q-switched Nd:YAG laser and fractional carbon dioxide laser for the treatment of solar lentigines in Asians. Lasers Surg Med. 2016;48(4):354-359. https://pubmed.ncbi.nlm.nih.gov/27096729/
Hedelund L, Haak CS, Togsverd-Bo K, et al. Fractional CO2 laser resurfacing for atrophic acne scars: a randomized controlled trial with blinded response evaluation. Lasers Surg Med. 2012;44(6):447-452. https://pubmed.ncbi.nlm.nih.gov/22766970/
Levy T, Lerman I, Waibel J, et al. Expert consensus on clinical recommendations for fractional ablative CO2 laser, in facial skin rejuvenation treatment. Lasers Surg Med. 2025;57(1):15-26. https://pmc.ncbi.nlm.nih.gov/articles/PMC11776446/
Wenande E, Jacobsen K, Grove GL, et al. Imaging 1927 nm fractional thulium laser-tissue interactions: a spectrum of nonablative to ablative effects. J Cosmet Dermatol. 2025;24(7):e70304. https://pmc.ncbi.nlm.nih.gov/articles/PMC12264580/
Li X, Qin S, Shi S, et al. Prospective study of efficacy and safety of non-ablative 1927 nm fractional thulium fiber laser in Asian skin photoaging. Front Surg. 2023;10:1076848. https://doi.org/10.3389/fsurg.2023.1076848
North Bristol NHS Trust. Fractionated CO2 laser for acne scarring: information for patients (patient leaflet). https://www.nbt.nhs.uk/sites/default/files/Fractionated%20CO2%20laser%20for%20acne%20scarring_NBT03197.pdf
