Laser Resurfacing: CO2 vs Erbium vs Fractional Comparison

Last updated: 9 August 2026

An overview of laser resurfacing technology

Laser skin resurfacing remains one of the most effective treatments for photoageing, acne scarring, and textural irregularities. The principle is controlled thermal injury: the laser ablates or coagulates damaged tissue, triggering wound healing and collagen formation. The choice between CO2, erbium, and fractional delivery significantly impacts outcomes, downtime, and risk.

CO2 Laser Resurfacing

Operating at 10,600nm, CO2 lasers produce both ablation and significant thermal coagulation. This dual effect makes them exceptionally powerful for deep wrinkles and severe scarring. Advantages include deepest tissue remodelling (20-60 micrometres per pass), superior collagen contraction (15-20 percent immediate tightening), and the most dramatic single-treatment results. Limitations include 7-14 days downtime, higher PIH risk in Fitzpatrick III+, and prolonged erythema.

Erbium:YAG laser resurfacing

At 2,940nm with 10x greater water absorption than CO2, erbium lasers offer precise ablation (2-5 micrometres per pass) with minimal thermal damage (10-40 micrometres). Recovery is 3-5 days. Lower risk of dyspigmentation makes it suitable for Fitzpatrick III-IV. However, less tissue tightening and reduced efficacy for severe photodamage as standalone.

Fractional laser technology

Fractional photothermolysis creates thousands of microscopic treatment zones surrounded by intact tissue, enabling rapid healing with reduced downtime and risk. Fractional CO2 offers 5-25 percent coverage per session with 3-7 days recovery. Fractional erbium provides 2-4 days recovery for mild-moderate concerns. Non-ablative fractional (1540-1927nm) has 1-3 days downtime but needs 4-6 sessions.

Choosing the right laser

1. Deep wrinkles and severe scarring warrant CO2 protocols
2. Higher Fitzpatrick types benefit from erbium or non-ablative fractional
3. Fractional approaches suit patients with limited downtime availability
4. Single CO2 sessions may be more cost-effective than multiple fractional treatments
5. Many clinics now combine ablative with non-ablative passes in the same session

Frequently asked questions

Best for acne scars?

Fractional CO2 offers best evidence: 50-75 percent improvement after 2-3 sessions. Ice-pick scars may need TCA CROSS first.

How long do results last?

Collagen remodelling continues 6-12 months. Results last 5-10 years with sun protection.

Safe for darker skin?

With conservative parameters, yes. Erbium and low-density fractional carry lowest risk for Fitzpatrick III-V. Pre-treatment with tyrosinase inhibitors for 4-6 weeks helps.

The two wavelengths

• CO2 (10,600 nm) — strongly absorbed by water, removes tissue and delivers significant residual heat to the layer beneath. That heat drives collagen contraction and remodelling, which is why CO2 generally produces the strongest result, and also why it involves the longest recovery.
• Erbium:YAG (2,940 nm) — absorbed by water roughly an order of magnitude more strongly than CO2, so it ablates more precisely with less heat spreading sideways. Recovery is usually shorter and the risk of prolonged redness and pigment change is lower, but the tightening effect is more modest.

Fully ablative versus fractional

Fully ablative treatment removes the whole surface of the treated area. It produces the strongest change and the longest healing. Fractional treatment creates a grid of microscopic treatment columns and leaves untreated skin between them, which speeds healing considerably. Most current practice is fractional, and both CO2 and erbium can be delivered fractionally.

Choosing between them

The choice is a trade between result and recovery, not between good and bad. Deeper scarring and significant photodamage generally need CO2. Where downtime must be limited or the skin type carries higher pigmentary risk, erbium or a non-ablative fractional device may be more appropriate.

Risks

Recognised complications for both include prolonged redness, post-inflammatory hyperpigmentation, permanent hypopigmentation, infection including reactivation of cold sores, and scarring. Risk of pigmentary change rises with darker skin types and with sun exposure before or after treatment.

Skin type is the dominant safety variable in any resurfacing decision. A test patch is reasonable to request.

General information only, not medical advice. Whether any treatment is appropriate depends on an individual assessment by a qualified clinician.