Skin rejuvenation (laser, microneedling, radiofrequency)

What it is and how it works

All the procedures follow the same principle: they inflict a measured amount of damage that the skin then repairs. Fractional lasers create a grid of tiny columns of heat and leave the skin in between intact, so that it heals quickly from the edges. Ablative lasers such as CO2 or erbium lasers remove tissue in these columns, non-ablative lasers only heat it and leave the surface intact. Microneedling uses fine needles to create mechanical micro-injuries. In radiofrequency microneedling, the needles additionally deliver high-frequency energy into the deeper layers, and non-invasive radiofrequency heats the skin from the outside in order to tighten it. IPL (intense pulsed light) is not a laser but a flash lamp with a broad light spectrum that targets mainly red blood vessels and brown pigment.

That the skin is actually remodeled in the process has been measured in tissue samples: after fractional laser treatment the connective tissue is remodeled and new collagen is formed (Orringer 2012). That is what all the devices are about. How this differs from other approaches: Tretinoin is a prescription-only cream that softens fine wrinkles caused by photoaging in studies, as a daily application rather than a session in a practice. PRP and exosomes are often applied after microneedling; their own contribution is then hard to separate from the needling. Red light does not create an injury and has not yet been robustly shown to work against skin aging.

What the studies show

Orringer 2012 – collagen in tissue samples

34 adults with photodamaged skin were treated at separate sites with a fully ablative and a fractional CO2 laser, after which tissue samples were taken at several time points. Both procedures triggered marked remodeling of the connective tissue and new collagen formation. After one fractional session, the collagen response reached about 40 to 50 percent of the fully ablative treatment, so it was similar in kind but weaker and shorter.

Karsai 2010 – fractional CO2 versus erbium laser, double-blind

Randomized, double-blind split-face study from Karlsruhe with 28 people with fine wrinkles around the eyes. Each side received one session, one with a fractional CO2 laser, the other with a fractional erbium laser. After three months, the measured wrinkle depth had decreased by about 20 percent and the wrinkle score by about 10 percent, with no appreciable difference between the lasers. The authors rate the effect of one session as noticeable but limited; several sessions are probably needed for the full effect.

Hedelund 2006 – IPL versus untreated side of the face

Randomized split-face study from Copenhagen with 32 women with fair skin (skin types I to III). One side received three IPL treatments at monthly intervals, the other remained untreated, and assessment was blinded for up to nine months afterwards. Skin texture improved significantly at almost all time points; one month after treatment, the treated side looked better in 23 of 28 women. Small blood vessels and irregular pigmentation improved at all time points. For wrinkles, there was no difference from the untreated side.

Microneedling and radiofrequency – systematic reviews

A review of facial microneedling pooled 21 studies with 723 treated people, mostly with several sessions; the most common side effects were temporary redness (6.8 percent) and scaling (1.7 percent). The authors stress that uniform measures for the aesthetic outcome are lacking (Foppiani 2025). On radiofrequency microneedling, a review evaluated 20 studies with 558 participants and found consistent improvements in skin texture and firmness without serious complications (Kumar 2026). For non-invasive radiofrequency, a review by the same research group with 15 studies and 1,230 participants reached similar results, with a low mean pain score of 1.94 on a ten-point scale; the authors rated the confidence in the findings as moderate (Kumar 2025).

Cochrane 2016 – acne scars

The Cochrane review found 24 randomized studies with 789 adults on treatments for acne scars. In one study with 64 people, those treated with a fractional laser reported improvement more often than those treated with a non-fractional, non-ablative laser; in another with 40 people, fractional laser and fractional radiofrequency performed comparably. The authors rated the quality of evidence for these comparisons as very low (Abdel Hay 2016).

What users report

On satisfaction there are published surveys within studies, not proof of efficacy. In the microneedling review, a pooled 83 percent of those treated were satisfied (95 percent confidence interval 76 to 88 percent; Foppiani 2025). After radiofrequency microneedling, satisfaction rates were above 90 percent in most studies (Kumar 2026), after non-invasive radiofrequency between 82 and 100 percent in 13 studies (Kumar 2025). The double-blind laser study is more sober: satisfaction was fair, but the majority would have undergone the treatment again (Karsai 2010). In the IPL study, 58 percent reported a mild to moderate improvement in skin texture, while for wrinkles 68 percent saw no effect or an uncertain one (Hedelund 2006). In this study, self-assessment therefore matched the blinded findings.

Where the data stop

The studies measure appearance after weeks to months. Whether repeated treatments over years slow skin aging, that is, whether the skin stays young for longer in the sense of “skin longevity”, has not been studied. Measurement itself is also difficult: there are no uniform measures for the aesthetic outcome, which makes studies hard to compare (Foppiani 2025).

Most studies are small and compare against the untreated side of the face or another device, hardly ever against a sham treatment. Devices, settings and numbers of sessions differ widely, so results are hard to transfer. The two current reviews on radiofrequency come from the same research group, which itself qualifies its conclusions because of methodological weaknesses of the individual studies and criticizes that downtime is hardly reported (Kumar 2025). For acne scars, the randomized evidence according to Cochrane is very low.

Status, approval and legal

In Germany, the Ordinance on Protection against the Harmful Effects of Non-Ionizing Radiation in Applications on Humans (NiSV) has regulated lasers, IPL and radiofrequency for cosmetic purposes since December 31, 2020 (BMUV). Ablative laser applications and laser or IPL applications that breach the epidermis as a protective barrier, as well as the treatment of vascular changes and pigmented skin changes, may only be performed by licensed physicians with appropriate specialist or continuing training (§ 5 NiSV). The same applies to radiofrequency applications that breach the epidermis, and thus also to radiofrequency microneedling (§ 6 NiSV).

Since December 31, 2022, other cosmetic laser and IPL applications may only be performed by people with certified expertise (BMUV). Mechanical microneedling without radiation or radiofrequency does not fall under the NiSV. Patients usually pay for aesthetic treatments themselves.

Safety

Redness, swelling and pain in the first few days are part of it and are the most common side effects. An analysis of 961 treatments with a non-ablative fractional laser found complications in 7.6 percent, most often acne-like eruptions (1.87 percent) and herpes outbreaks (1.77 percent); all were temporary, and no scarring occurred. Temporary pigmented spots after inflammation were more common in darker skin types (Graber 2008). Anyone prone to herpes or with a darker skin type should raise this before treatment.

In the IPL study, three participants withdrew because of pain, and one was left with a scar (Hedelund 2006). For all procedures that penetrate the skin, hygiene determines the risk of infection; how serious this can become is shown by the case of HIV transmissions after unsterile PRP microneedling in a US cosmetic spa, described on the PRP page.

Sources

• Orringer JS et al., Dermatol Surg 2012 – collagen response after fractional and fully ablative CO2 laser, tissue samples, 34 people (PMID 22805255)
• Karsai S et al., Lasers Surg Med 2010 – randomized, double-blind split-face study, fractional CO2 versus erbium laser, 28 people (PMID 20166156)
• Hedelund L et al., Arch Dermatol 2006 – randomized split-face study, IPL versus untreated, blinded assessment, 32 women (PMID 16924047)
• Foppiani JA et al., Aesthetic Plast Surg 2025 – systematic review, facial microneedling, 21 studies, 723 treated people (PMID 40542236)
• Kumar N et al., J Cosmet Dermatol 2026 – systematic review, facial radiofrequency microneedling, 20 studies, 558 participants (PMID 41947517)
• Kumar N et al., Aesthet Surg J Open Forum 2025 – systematic review, facial radiofrequency, 15 studies, 1,230 participants (PMID 41426292)
• Abdel Hay R et al., Cochrane Database Syst Rev 2016 – treatments for acne scars, 24 randomized studies, 789 people (PMID 27038134)
• Graber EM et al., Dermatol Surg 2008 – side effects and complications, 961 fractional laser treatments (PMID 18190541)
• German Ordinance on Protection against the Harmful Effects of Non-Ionizing Radiation in Applications on Humans (NiSV), §§ 5 and 6 – physician-only applications
• German Federal Environment Ministry (BMUV) – basic questions on the NiSV: in force since December 31, 2020, certified expertise required since December 31, 2022