How does CO2 laser work?
Energy absorbed by water in tissue vaporises the targeted skin layer and creates a heat effect in the surrounding tissue. As the skin repairs itself, new collagen production may be stimulated.
The light is absorbed by water-containing skin cells. Depending on energy density, only a thin surface layer or deeper channels may be treated. Treating the whole skin surface and treating tiny dots in a fractional pattern differ clearly in recovery time and risk.
In fractional treatment, islands of intact skin are left between the treated spots, so recovery is usually quicker. The approach chosen depends on the problem being treated, skin type and the downtime available.
When is CO2 laser considered?
It may be used for acne scars, fine to moderate lines, sun-related texture changes and removal of some benign skin lesions. It is not a suitable option for every concern.
Pitted acne scars and uneven texture sometimes need a plan spread over several sessions. Intense settings aimed at a more visible change mean a longer recovery. Using it for benign growths needs a separate medical assessment, because a suspicious lesion must be diagnosed first.
Gentler options with shorter recovery also exist; the fractional laser and microneedling pages describe them. The doctor decides which fits at consultation.
How does recovery go and what are the risks?
Redness, swelling, oozing and crusting may be expected, and the time depends on treatment depth. Risks include infection, pigment change that can last a long time, prolonged redness and scarring.
After intense treatment the skin may crust for days and redness can last weeks. Following the aftercare plan from the doctor, protecting the skin from the sun and attending the follow-up visits are important. Fever, increasing pain, pus or rapidly spreading redness call for contacting the doctor without delay.
The risk of pigmentation is higher on darker skin such as Fitzpatrick types IV–VI. People with a cold sore history may be given a preventive plan by the doctor. See the laser aftercare guide for care details.
Who should not have CO2 laser, or should wait?
Active infection, open wounds, pregnancy, recent tanning, recent isotretinoin use and conditions that impair wound healing usually lead to postponement or another method.
A tendency to keloid or thick scars, frequent cold sores, skin diseases and medicines in use should be told to the doctor. Photosensitising medicines and some herbal products also affect the assessment.
Expectations, risks, recovery time and alternatives should be discussed openly at consultation. The questions on the laser safety page can also help before deciding.
Frequently asked questions
Are CO2 laser and fractional laser the same?
No. CO2 is a type of laser; fractional describes how the beam is delivered in dots. Fractional treatment can be done with CO2 or another wavelength.
How long do people stay out of social life after CO2 laser?
It depends on intensity: a few days for light settings and longer for intense ones. The doctor plans this in advance.
Is one session enough?
It depends on the concern and the settings. Some cases need one session, others several; results and timing differ from person to person.
Is CO2 laser done in summer?
Sun exposure makes healing skin prone to discolouration. Season and the ability to avoid the sun are assessed during planning.
Is CO2 laser painful?
Discomfort varies with the person and the settings. The doctor usually plans a numbing cream or another anaesthetic method.
Sources (3)
- Lasers in Surgery and Medicine: Expert Consensus on Clinical Recommendations for Fractional Ablative CO2 Laser, in Facial Skin Rejuvenation Treatment (2025)
- European Commission, Medical Device Coordination Group: MDCG 2023-5: Guidance on qualification and classification of Annex XVI products (2023)
- Australasian Journal of Dermatology: Prevention of Post-Inflammatory Hyperpigmentation in Skin of Colour: A Systematic Review (2025)
This content is for general information and does not replace a personal medical assessment.