Fractional CO2 Laser

Fractional CO2 laser delivers thousands of microscopic treatment zones into the skin; the surrounding untreated tissue promotes rapid healing, while the micro-thermal zones stimulate collagen production to elevate the scar base. It is ideal for boxcar and mild-to-moderate rolling scars on skin free of active acne, typically requiring 3–5 sessions spaced 4–8 weeks apart, with erythema and peeling lasting 5–7 days.

Medically reviewed by BS.Ths.CKI Kim Kha — BonBoz Clinic

Mechanism

The CO2 laser beam is absorbed by intracellular water, vaporizing tissue in microscopic thermal zones (MTZs) several hundred micrometers deep while generating surrounding zones of thermal damage. The body responds through a natural wound-healing cascade: contraction of existing collagen and neocollagenesis over the course of 4–12 weeks. Because only 10–30% of the skin's surface is treated in each session, the skin recovers within approximately one week, unlike the weeks-long downtime associated with traditional fully ablative lasers.

Which Types of Scars Are Best Suited?

Best response: shallow-to-medium boxcar scars, rolling scars (following subcision), uneven skin texture, and enlarged pores. Limited efficacy: deep ice-pick scars (require combination with TCA cross), hypertrophic/keloid scars (contraindicated — may worsen the condition), and active inflammatory acne.

Why Are Multiple Sessions Required?

Each session treats only a fraction of the skin's surface, and collagen remodeling takes time. Results are cumulative; scheduling sessions too closely together will not accelerate results and increases the risk of hyperpigmentation. The dermatologist will estimate the required number of sessions following a skin analysis and adjust the plan based on your actual clinical response.

Darker Skin Tones and the Risk of Hyperpigmentation

Vietnamese skin is more prone to post-inflammatory hyperpigmentation (PIH) than lighter skin types. Therefore, energy parameters, treatment density, and post-procedure care must be strictly personalized; rigorous sun protection for at least 4 weeks after each session is a mandatory requirement, not merely a recommendation. For very dark skin tones or patients with a history of prolonged PIH, the doctor may recommend microneedling RF as the preferred alternative.

At BonBoz

Our dermatologists conduct in-depth skin analyses, classify scar types, screen for active inflammatory acne and medication history, customize parameters for each facial zone, administer topical anesthesia, and provide detailed day-by-day aftercare instructions. All procedures are performed directly by our doctors—never delegated to technicians—with scheduled follow-up visits to evaluate your progress before each subsequent session.

How is it performed?

Cleanse the face, apply topical numbing cream for 30–45 minutes, and remove the cream. The doctor performs the laser treatment section by section with pre-set parameters (density, energy, depth) — taking 15–30 minutes for the full face; patients experience a tolerable warm, prickling sensation. This is followed by cooling the skin, applying a recovery cream, and physical sunscreen.

Before the procedure

Discontinue topical retinoids 5–7 days prior and avoid exfoliating 1 week beforehand; inform the doctor if you are taking oral retinoids or anticoagulants, or if you have a history of cold sores (oral herpes) or keloid scars; avoid direct sun exposure and tanning for 2 weeks prior; arrive with clean, makeup-free skin.

After the procedure

Days 1–2: Skin will experience redness, warmth, and mild weeping; Days 3–7: Darkening and fine peeling will occur — do not pick; use prescribed recovery medication, cleanse with physiological saline, and apply SPF 50 sunscreen every 2–3 hours when outdoors. Avoid saunas, strenuous exercise, and swimming pools for 1 week; attend a follow-up visit before the next session (4–8 weeks).

Possible risks — your doctor explains them before treatment

Post-inflammatory hyperpigmentation (temporary darkening) — higher risk in darker skin tones and with inadequate sun protection
Prolonged redness lasting several weeks in sensitive skin
Infection or herpes outbreak if aftercare is improper / with a prior history
Patchy hypopigmentation or new scarring if settings are too aggressive — the reason parameters must be set by a physician
Results offer partial improvement, not complete scar removal

Who should NOT have this?

Active inflammatory or cystic acne in the treatment area
History of keloid scarring or active keloids on the face
Currently taking oral retinoids or have discontinued them without meeting the required waiting period specified by the physician
Pregnant or breastfeeding (insufficient safety data — postpone treatment)
Recent sunburn, active dermatitis, or active herpes simplex infection
Unable to maintain strict sun protection for 4 weeks following each session (e.g., continuous outdoor work)

BS.Ths.CKI Kim Kha

Aesthetic Dermatology

Graduated as a General Practitioner — Tay Nguyen University (2018)
Specialist Level I in Dermatology — Pham Ngoc Thach University of Medicine, degree awarded in 2025
Medical Practicing Certificate No. 009784/ĐL-CCHN — Issued by the Department of Health of Dak Lak Province on 15/10/2021
Over 8 years of experience in aesthetic dermatology practice (since 2018), including over 4 years of practice with an official Medical Practicing Certificate
Primary Specialization in Plastic and Reconstructive Surgery; Certificates in Dermatological Procedures & Minor Surgery, Microsurgery, and Lasers & Light Therapies in Dermatology
Certificates in Dermal Fillers, Botox, and Thread Lifts; Certificates in Emergency Resuscitation and Infection Control
Formerly practiced at the Aesthetic Dermatology Unit — Post and Telecommunications General Hospital (2019–2021) and Venus Sunrise Clinic (2022–2024) before joining BonBoz Clinic (2025)
Former lecturer in Aesthetic Dermatology Theory at Ana Aesthetic Training School (2018–2019)
Over 5,000 clinical dermatology cases treated

Đặt lịch với bác sỹ

Book a consultation with a doctor

Choose a date, time slot and doctor — the clinic calls to confirm within 5 minutes during opening hours. Free consultation, no commitment.

Full name

Phone number

Preferred date · Preferred time · Doctor

Preferred date

Preferred time

Doctor

The clinic will call to confirm within 5 minutes during opening hours (08:00–20:00, daily). This is not yet a confirmed slot.

I agree to let BonBoz contact me for consultation using the information I provided, and I have read the Personal Data Protection Policy.

You do not have to describe your health condition here — you can discuss it directly with the doctor at your visit.

Free consultation — no obligation, no sales pressure.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Frequently asked questions

Is Fractional CO2 Laser painful?

Topical numbing cream is applied, so you will mostly feel a prickling heat sensation that is well-tolerated. Afterwards, the skin will feel warm and sting for a few hours, similar to a mild sunburn.

How soon can I return to work?

Redness and peeling typically last about 5–7 days. Many clients return to work by day 3–4 with slightly pink skin if they practice good sun protection; if your job requires a pristine appearance, taking 1 week off is recommended.

How many sessions are needed?

Usually 3–5 sessions spaced 4–8 weeks apart for moderate scarring; severe scarring requires more. The doctor will estimate the number of sessions after a skin analysis and adjust based on your response.

How long does it take to see results?

The skin becomes smoother after 2–3 weeks; noticeable scar lifting is seen after 2–3 sessions as collagen takes 1–3 months to remodel.

Does it cause hyperpigmentation after laser treatment?

Temporary post-inflammatory hyperpigmentation (PIH) can occur, especially in darker skin tones. Strict sun protection and prescribed topical medications significantly reduce this risk; if pigmentation occurs, it usually fades within a few weeks to months.

How is it different from traditional CO2 laser?

Traditional CO2 lasers ablate the entire skin surface, requiring 2–4 weeks of downtime with higher risks; fractional CO2 targets only a fraction of the skin via microscopic thermal zones, resulting in a 1-week recovery.

What can it be combined with for better results?

Subcision for rolling scars, TCA cross for ice-pick scars, and PRP to accelerate healing. The doctor will customize the sequence based on your specific scar types.

What is the best season to do it?

It can be performed year-round, but periods with less sun exposure are more favorable since post-procedure sun protection is critical.

Can thin, sensitive skin undergo this treatment?

Yes, using milder energy settings, or the doctor may prefer microneedling RF depending on the skin assessment.

Do I need maintenance treatments after completing the regimen?

Maintenance laser sessions are not necessary for scars that have already improved; maintaining acne control and diligent sun protection are essential to prevent new scars from forming.