Laser and Skin

Wrinkles and lasers: rebuilding instead of filling

A laser does not treat a wrinkle by adding anything to it. It sets a controlled heat injury in the dermis, the body repairs that injury with new collagen, and the rebuilding takes 3 to 6 months before the surface looks different. Ablative resurfacing does this in 1 or 2 sessions at the price of 5 to 10 days of open skin and weeks of redness; non-ablative systems keep the surface intact, need 4 to 6 sessions and cost a few hours to 3 days of pinkness.

How a heat injury turns into firmer skin

From about the age of 25 the dermis loses collagen at roughly 1% a year, elastin fibres fray, and the skin becomes thinner and slower to spring back. A resurfacing laser works on one physical fact: its wavelength is absorbed by the water inside tissue. A carbon dioxide laser at 10,600 nanometres and an erbium laser at 2,940 nanometres vaporise the surface and heat the layer beneath it; non-ablative lasers between 1,320 and 1,927 nanometres pass through the epidermis and heat the dermis alone. In every case the body reads the heated zone as a wound, and wound repair means fibroblasts laying down new collagen and elastin. That is the whole mechanism. Nothing is injected, nothing is filled.

The timetable follows from the biology, not from the device. The first visible change in fine lines typically appears 3 to 8 weeks after an ablative session, and the remodelling continues for 3 to 6 months. Anyone who expects a result 2 weeks after treatment is working against the calendar of their own connective tissue. Non-ablative courses usually run to 4 to 6 sessions at intervals of 2 to 4 weeks, fractional courses to 4 or 5 sessions about a month apart, and the honest moment to judge the outcome is 3 months after the last session, not before.

Ablative, fractional or non-ablative

Ablative lasers remove the surface. A pulsed carbon dioxide laser vaporises 20 to 60 micrometres with each pass and leaves a zone of heat damage 100 to 150 micrometres deep, which is what tightens the skin and also what prolongs the healing. Water absorbs the erbium wavelength 12 to 18 times more efficiently, so an erbium laser removes 3 to 5 micrometres per pass with only 10 to 40 micrometres of heat damage: more precise, less tightening, faster recovery. The skin closes again after about 8 days with carbon dioxide and about 5 days with erbium. Full-field carbon dioxide resurfacing in older series improved wrinkles by up to 90%, but 55% of those patients had acne, pigment change or infection along the way.

Fractional devices split the beam into thousands of microcolumns, each under 400 micrometres wide and up to 1,300 micrometres deep, and leave the skin between them untouched so it can heal the columns from the sides. Recovery drops to 5 to 10 days for fractional carbon dioxide and 1 to 3 days for fractional erbium; in one study 72% of participants improved, by an average of 40%, and 80% called the reduction in wrinkles satisfactory. Non-ablative fractional lasers go a step further and leave the epidermis intact altogether. The price of comfort is effect: 4 to 6 sessions produce what the literature calls a moderate change, which suits fine lines and early photoageing better than deep creases.

Two rules apply whichever you choose. First, the deeper the treatment, the more it belongs in medical hands. Some countries have written that down, Germany among them, where ablative laser resurfacing has been reserved for doctors since the end of 2020; in the UK and the US the safeguard is the practitioner's qualification rather than a statute. Second, skin colour sets the limits. Full-field carbon dioxide resurfacing is not recommended for Fitzpatrick phototypes IV and above, erbium and fractional settings are preferred there, and post-inflammatory darkening is both more common and more persistent in darker skin. If you are unsure of your phototype, the Sun Exposure Timer lists the 6 types with a description of each.

What the laser cannot do

It cannot replace volume. Hollow cheeks, deep nasolabial folds and marionette lines come from the loss of fat pads and bone, not from a slack surface, and a tighter surface over a sunken frame still looks sunken. That is a job for filling or for surgery, not for rebuilding. A laser also cannot lift an excess of skin: if you can gather a fold of more than about 1 centimetre of loose cheek or neck skin between two fingers, no amount of new collagen will shorten it, and the honest recommendation is a surgical lift.

And it does nothing about the cause. In a study of 298 women aged 30 to 78, ultraviolet exposure accounted for about 80% of the visible signs of facial ageing, and a difference of 2 percentage points in sun damage shifted perceived age by roughly 3 years. Fresh collagen laid down after resurfacing is exactly as vulnerable to ultraviolet light as the old collagen was, so a treated face that goes back into the sun unprotected is being taken apart again while it is still being rebuilt. Daily SPF 30 from a UV index of 3 upwards and a retinoid at night are the maintenance that keeps the result; the ingredients with evidence have their own guide.

Which wrinkle responds to what

Fine crinkling on the cheeks, the upper lip and around the eyes comes from a thinning dermis and lost collagen. It answers best to resurfacing and to needling, because both rebuild exactly the layer that has gone. Lines on the forehead and between the brows are drawn by muscle pull; as long as they appear only on expression, they respond to treatments that quieten the muscle, and a laser will barely touch them. Static lines that stay in a relaxed face are a mixture of both, and folds caused by sagging volume, at the cheek contour or beside the mouth, need filling.

Depth matters as much as type. Eyelid skin is among the thinnest on the body, less than half the thickness of the cheek, while a fractional column can reach 1,300 micrometres, so the same setting that resurfaces a chin would scar an eyelid or a neck. A practitioner who quotes 1 energy level for the whole face has not thought about this, and one who names 3 or 4 zones with different settings has.

The self-test takes 10 seconds. Gently stretch the skin on either side of the wrinkle. If the line vanishes, it is a surface problem and will respond to rebuilding. If it stays, the cause is volume loss or muscle pull underneath, and resurfacing will improve the texture while leaving the fold where it is.

Planning the downtime

After ablative treatment the skin is an open wound. It weeps, crusts and needs cleaning 2 to 5 times a day with saline or a dilute vinegar solution, followed by ointment. It peels around day 5 to 7 and is closed after 5 to 8 days; normal activity resumes after 3 to 8 days with full-field erbium and after 14 to 21 days with full-field carbon dioxide. Then comes the redness. It fades over 2 to 3 months, can take up to 12 months in fair or red-haired people, and can be covered with camouflage make-up once the surface has closed, usually after about 2 weeks. Retinoid creams and glycolic acid go back into the routine about 6 weeks later.

Non-ablative sessions cost almost nothing in downtime. A full face takes about 30 minutes, the skin feels like mild sunburn for about an hour, stays swollen for 2 to 3 days and pink for 3 to 5 days, and a bronze, flaky tone can linger for 3 to 14 days. Most people go back to work the same or the following day.

Preparation is part of the plan. If you have taken oral isotretinoin, wait 6 to 12 months, because wound healing is delayed. If you get cold sores, you take antiviral tablets from the day before treatment for about 14 days, since a herpes flare on freshly resurfaced skin can scar. Many clinics ask for 4 weeks of a topical retinoid beforehand and 4 to 6 weeks without direct sun afterwards. If you have a fixed date, count backwards: at least 3 months for ablative work, at least 4 weeks for non-ablative, and never the fortnight before a wedding. Prices vary with country and clinic; a non-ablative session commonly runs to 200 to 600 EUR or USD, a full-face fractional ablative treatment to 1,500 to 3,500, and quotes that leave out the follow-up visits are not complete.

Questions to ask before you book

Frequently asked

When will I see the result of laser resurfacing?

Collagen remodelling takes 3 to 6 months. The first change in fine lines usually appears 3 to 8 weeks after an ablative session, and directly after any session you see redness and swelling, not tightening.

How many laser sessions do wrinkles need?

Full-field ablative resurfacing is usually a single treatment, fractional ablative 1 to 2, and non-ablative lasers 4 to 6 sessions spaced 2 to 4 weeks apart. The milder the session, the more of them it takes.

Does laser resurfacing help deep nasolabial folds?

Only at the surface. These folds come from lost fat and bone rather than from slack skin, and if the fold stays when you stretch the skin beside it, filling rather than rebuilding is the answer.

Is laser resurfacing suitable for darker skin?

With limits. Full-field carbon dioxide resurfacing is not recommended for Fitzpatrick phototypes IV and above; erbium or fractional devices with conservative settings and a test patch are used instead, because post-inflammatory darkening is more common and lasts longer in darker skin.

How long does the redness last?

A few hours to 3 days after non-ablative treatment, about 2 weeks after fractional carbon dioxide, 3 to 4 weeks after full-field erbium, and several weeks to months after full-field carbon dioxide, occasionally up to 12 months in fair-skinned people.

Who should not have laser resurfacing?

Anyone who has taken oral isotretinoin in the last 6 to 12 months, has an active skin infection or cold sore, tends to form keloids, has vitiligo, or cannot avoid direct sun for 4 to 6 weeks afterwards. Pregnancy and a fresh tan are reasons to postpone.

Sources

• StatPearls: Ablative Laser Resurfacing (NCBI Bookshelf) · wavelengths 10,600 and 2,940 nm, ablation depths 20 to 60 and 3 to 5 micrometres, re-epithelialisation 8 and 5 days, recovery 1 to 21 days by device, erythema durations, isotretinoin 6 to 12 months, phototype IV and above, improvement up to 90%, antiviral prophylaxis
• Preissig J, Hamilton K, Markus R. Current Laser Resurfacing Technologies, Semin Plast Surg 2012 (PMC) · non-ablative wavelengths 1,319 to 1,927 nm, 4 to 6 treatments at 2 to 4 week intervals with hours of erythema, fractional carbon dioxide 72% improved by an average of 40% with 80% satisfied, 55% side effects after full-field carbon dioxide
• DermNet: Fractional laser treatment · 4 to 5 non-ablative sessions a month apart, about 30 minutes per full face, swelling 2 to 3 days, pink 3 to 5 days, bronze 3 to 14 days, optimal result over 3 to 4 months
• Flament F et al., Effect of the sun on visible clinical signs of aging in Caucasian skin, Clin Cosmet Investig Dermatol 2013 (PMC) · 298 women aged 30 to 78; ultraviolet exposure responsible for about 80% of visible facial ageing signs; 2% of sun damage equals about 3 years of perceived age

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This guide is for general information. It does not replace medical or professional cosmetic advice or an examination.