An ablative laser is a type of medical laser that removes skin by vaporizing its outer layers. The laser energy is absorbed by water in skin cells, heating them so rapidly that the tissue is destroyed in a controlled way. This triggers the body’s wound-healing response, which rebuilds the treated area with fresh skin and new collagen. Ablative lasers produce the most dramatic results of any laser resurfacing method, but they also require the longest recovery.
How Ablative Lasers Work
All ablative lasers target water inside skin cells. When the laser beam hits the skin, water molecules absorb the energy and heat up almost instantly, causing the cells to vaporize. The key engineering challenge is speed: the laser pulse has to deliver its energy in less than one millisecond so the heat doesn’t have time to spread sideways into surrounding tissue. This keeps damage confined to the targeted layer.
Removing the outer skin is only half the effect. The heat that penetrates beneath the vaporized layer causes a controlled injury to the deeper skin, where collagen lives. This thermal injury triggers a healing cascade that produces new collagen, elastin, and other structural proteins over the following weeks and months. The result is skin that’s not only resurfaced on top but firmer and smoother underneath.
The Two Main Laser Types
Two ablative lasers dominate clinical use, and they differ mainly in how aggressively they heat tissue.
The CO2 laser operates at a wavelength of 10,600 nanometers. It penetrates relatively deeply and leaves a band of heat-altered collagen measuring up to 150 micrometers beneath the vaporized surface. That extra thermal damage is actually useful for stimulating robust collagen remodeling, but it also means more downtime and a higher risk of side effects. CO2 lasers are generally considered the gold standard for deep wrinkles, severe sun damage, and significant scarring.
The Erbium:YAG laser operates at 2,940 nanometers, a wavelength that water absorbs about 15 times more efficiently than the CO2 wavelength. Because the energy is absorbed so quickly at the surface, less heat travels deeper. Residual thermal damage is typically under 50 micrometers, roughly a third of what a CO2 laser produces. This makes Erbium:YAG a gentler option with faster healing, though the collagen-tightening effect is less pronounced.
Full-Field vs. Fractional Ablation
Traditional (full-field) ablative lasers vaporize every bit of skin in the treatment area. Think of a TV screen where every pixel is turned on. This delivers powerful results but creates a large, open wound that takes weeks to heal.
Fractional ablative lasers changed the equation. Instead of treating the entire surface, they create thousands of tiny columns of vaporized tissue, each about one-tenth the width of a hair follicle. Between these columns, the skin is completely untouched. Those islands of healthy tissue act as healing reservoirs, allowing the skin to repair itself much faster while still delivering deep penetrating treatment. The tradeoff is that fractional treatments are less dramatic per session and sometimes require multiple rounds to match the results of a single full-field treatment.
Most ablative laser procedures performed today use fractional technology, because it offers a practical middle ground: meaningful improvement with a recovery period of days rather than weeks.
What Ablative Lasers Treat
The list of conditions treated with ablative lasers is broad. The most common reasons people seek treatment are fine to deep facial wrinkles, sun-damaged skin, and acne scars. But ablative lasers are also used for surgical or traumatic scars, precancerous spots like actinic keratoses, warts, skin tags, and a variety of benign growths including seborrheic keratoses and small blood vessel lesions.
For skin rejuvenation specifically, ablative resurfacing produces more visible improvement than any non-ablative laser. Non-ablative devices heat the deeper skin without removing the surface at all, which means less downtime but also more subtle results. Ablative treatment physically removes damaged skin and replaces it, which is why it remains the preferred option when someone wants the most improvement possible in one or two sessions.
What the Procedure Feels Like
Ablative laser treatment is painful enough to require numbing. For smaller areas, a topical anesthetic cream applied 30 to 60 minutes beforehand is often sufficient. For full-face resurfacing, especially with a CO2 laser, local anesthetic injections or light sedation are common. Patients typically describe the sensation as intense heat or snapping during the procedure, with CO2 lasers generally rated as more painful than Erbium:YAG.
Before treatment, you’ll typically be prescribed an antiviral medication to prevent cold sore reactivation, which is a well-known risk after any procedure that disrupts the skin barrier on the face. This is standard practice regardless of whether you have a history of cold sores.
Recovery and Healing
After a fractional ablative session, the treated skin looks red, swollen, and raw. For the first few days, keeping the wound moist is essential. Clinicians typically recommend cold compresses and a moisturizing ointment (petroleum jelly or a similar barrier product) applied several times daily. Moist wound care has been shown to shorten healing time and reduce complications compared to letting the skin dry out and crust over.
With fractional CO2 treatment, most people can expect about five to seven days of visible wound healing before the skin closes over. Redness can persist for several weeks to a few months, gradually fading. Full-field ablative resurfacing takes longer, often two to three weeks before the raw surface fully re-epithelializes, with redness lasting even longer.
During recovery, sun protection is critical. The fresh skin is highly susceptible to pigmentation changes, and even brief unprotected sun exposure can cause lasting discoloration.
Risks and Side Effects
The most common complication after ablative resurfacing is temporary darkening of the skin, known as post-inflammatory hyperpigmentation. In one large retrospective study of 749 patients, it occurred in about 32% of cases. This darkening typically fades on its own over weeks to months but is more likely in people with darker skin tones.
Permanent lightening of the skin (hypopigmentation) is far less common, occurring in under 1% of patients in that same study. Bacterial infection rates with traditional ablative resurfacing range from 0.5% to 4.5%, and fungal infections from 1% to 3%. Fractional treatments carry lower infection risk because less total skin surface is disrupted.
Prolonged redness is expected rather than a true complication, but if redness persists beyond three to four months or is accompanied by raised texture, it could signal early scarring, which is the most serious (though rare) adverse outcome. People with a history of abnormal scarring should discuss this risk carefully before proceeding.
Who Gets the Best Results
Ablative lasers work best on lighter skin tones, primarily because the risk of pigmentation changes rises significantly with more melanin in the skin. That doesn’t mean darker-skinned individuals can’t be treated, but fractional settings with lower coverage percentages and conservative energy levels are important to reduce complications.
Ideal candidates have moderate to severe photoaging, acne scarring, or textural irregularities and are willing to accept a meaningful recovery period in exchange for more significant improvement. For mild concerns or people who can’t take time off, non-ablative or minimally ablative options may be more practical, even if the results are less dramatic per session.