What to expect from XERF, and its limits — what it can do, what it cannot, and what is not yet known
When a lifting treatment leaves people disappointed, it is more often because expectations and scope did not match than because of the treatment itself. We have divided this into three parts: what can be expected from XERF, which problems XERF does not address, and what research has not yet answered. Every figure is given with its source and design.
The short answer
What can be expected from XERF is that monopolar radiofrequency heat tightens sagging tissue and skin and induces collagen change; its size and duration have so far been observed in three studies without a control group. The studies reported blinded raters identifying photos 80% of the time and a mean GAIS of 2.75/4 (20 people · 1 session · 12 weeks), and 92.3% improvement as rated by the treating physicians (39 people · 2 sessions · 90 days, manufacturer supported), but follow-up goes to about 3 months at most and there are no data on effects lasting a year or more. Volume loss, fat and skin lax enough to fold are not problems XERF addresses. Miso Clinic (4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea; +82-53-428-2700) checks this scope with you before treatment and considers XERF when sagging is the main concern (clinical judgement).
What can be expected from XERF?
XERF is not a laser but monopolar radiofrequency. Current at two frequencies, 6.78 MHz and 2 MHz, produces heat through the resistance of the tissue; that heat contracts collagen and then induces regeneration over weeks to months. The principle is set out separately in The radiofrequency principle behind XERF.
| Study | Subjects · sessions · follow-up | Reported results | Design |
|---|---|---|---|
| Hwang 2025 | 20 women (aged 28–63, Fitzpatrick III · IV) · 1 session · 12 weeks | Blinded raters identified photos 80%, mean GAIS 2.75/4, satisfaction 7.84/10 | No control group |
| Weiss 2026 | 39 people · 2 sessions · 90 days | Improvement rated by treating physicians 84.6% at 30 days → 92.3% at 90 days | Manufacturer supported, no control group |
| Erlich 2026 | 16 people · 1 session · 3 months | Lower face 24–36 kJ, E60 · E10 · E5 tip combination | Retrospective, no control group |
In short, “improvement was observed at around 3 months in faces with sagging tissue” is as far as the data can speak.
How should the study figures be read?
Three things need to be looked at together.
- There is no control group. The studies did not compare with people who had no treatment. In a randomised trial of another lifting device (Ulthera) with an untreated control, 47.0% of untreated people were also classed as “improved” on blinded photo assessment (treated group 54.2%, not statistically significant). This means lighting · angle · swelling enter into the assessment, and it applies to every before-and-after comparison without a control group.
- Who assessed it differs. The 92.3% is the treating physicians’ assessment. In an analysis of 16 ultrasound lifting studies, ratings at the same 90 days split 92% for practitioners vs 42% for patients.
- It is short. Follow-up goes to about 3 months at most. Beyond that, nothing was measured.
So Miso Clinic explains XERF’s figures not as “proof” but as observations with measurements attached. This is also discussed in Density and XERF: why some say “no effect”.
What can XERF not do?
| Concern | Why XERF struggles | What we consider first |
|---|---|---|
| Hollow cheeks · temples | Heat does not create volume. Tightening a hollow face can make it look more hollow | Approaches that address volume, such as filler — XERF for cheek sagging |
| Reducing fat under the chin | XERF’s US 510(k) intended use is electrocoagulation · haemostasis, with no fat-reduction indication | Identify the cause — XERF and jawline sagging |
| Skin lax enough to fold | Beyond the scope of non-surgical devices | Surgical consultation |
| Thin, dull skin texture | Radiofrequency alone may lack the material | Adding a skin booster — XERF for thin skin |
| An angular lower face due to muscle | Heat does not reduce muscle volume | Botox consultation |
Checking before treatment whether a concern falls within XERF’s territory can by itself prevent much of the disappointment of “it had no effect” (clinical judgement).
What is not yet known?
| Category | Content |
|---|---|
| Confirmed | Three human studies (20 · 39 · 16 people), none with a control group, follow-up up to about 3 months |
| Not confirmed | Data on effects lasting 6 months · 1 year or more |
| Not confirmed | Studies comparing it under the same conditions with other devices such as Density · Thermage (a systematic analysis of radiofrequency, 15 studies · 1,230 people, also states that no direct device-to-device comparison exists) |
| Not confirmed | Differences in effect by tip size, and by shot count · number of sessions · interval |
| Preclinical data alone | Heat distribution of the two frequencies (Ko 2025 — computer simulation · porcine tissue, most authors work for the manufacturer) |
“Not known” does not mean “no effect”. We simply do not turn what has not yet been measured into a promise. For reference, XERF’s US 510(k) (K251327) was submitted for electrocoagulation · haemostasis without clinical trials, so its aesthetic effect has not been evaluated by the US FDA.
When and how are results judged?
- ImmediatelyTight feelingImmediate contraction and swelling. It settles within a few days.
- 2–4 weeksAn unclear windowThe immediate contraction has gone and new change is not yet enough. In radiofrequency research, clinical assessment was not significant at 4 weeks.
- Around 12 weeksTime to judgeThe point at which clinical assessment became significant in radiofrequency research, and also about where the XERF studies’ follow-up ends.
Miso Clinic takes photos with the same lighting · angle · expression before treatment, and retakes them under the same conditions at around 3 months to compare (clinical judgement). The timing of the next session is continued in XERF interval and number of sessions.
How much discomfort and risk is there?
Pain — in the 20-person XERF study, pain without anaesthesia was VAS 4–5 (Hwang 2025). Miso Clinic does not use heavy anaesthesia that completely blocks pain signals, because in data on older devices, heavy anaesthesia blocking pain feedback was pointed out as a risk factor for fat atrophy (Narins 2006 — about 4 per 10,000 treatments, not a current incidence). Side effects over time are set out in XERF side effects, read as a timeline.
Redness · blistering — in data on older radiofrequency devices, redness fell from 36.0% immediately to 16.7% at 72 hours and 3.9% at one month, and blistering was 2.3% immediately · 3.8% within 72 hours (Fitzpatrick 2003). These are figures for the 2002 high-energy single-pass technique and should not be read as current XERF incidences. We could not find data summarising adverse reaction rates specific to XERF.
Does Miso Clinic being a XERF ambassador have anything to do with results?
Miso Clinic is a XERF ambassador selected by Cynosure Lutronic, the maker of XERF. But this is the manufacturer’s selection; it is not a national qualification, a society certification or an assurance of results, and it does not mean better than other clinics. What decides the result is not ambassador status but whether the concern falls within XERF’s territory, and a design that fits the area.
What being an ambassador means and does not mean is set out separately in What it means that Miso Clinic is a XERF ambassador. The skin XERF suits is in Which skin types XERF suits, and the full map of XERF is in XERF lifting in Daegu: which skin it suits.
What to expect from XERF: frequently asked questions
Has the effect of XERF been proven by research?
There are three human studies (20, 39 and 16 people), but none has a control group, so they are observations rather than proof. One was manufacturer supported, and follow-up goes to about 3 months at most.
Will XERF fill hollow cheeks?
No. Heat does not create volume. Tightening a hollow face with heat can make it look more hollow, so we first consider approaches that address volume.
Does the effect of XERF last a year?
There are no XERF data at one year. The longest follow-up is about 3 months (12 weeks, 90 days). We do not promise a number of months for a period that has not been measured.
Does XERF hurt a lot?
There is a sensation of heat. In the 20-person XERF study, pain without anaesthesia was VAS 4-5. Miso Clinic does not use heavy anaesthesia that completely blocks pain signals.
Are results better at an ambassador clinic?
No. XERF ambassador status is a selection by the manufacturer; it is not a national qualification, a society certification or an assurance of results, and it does not mean better than other clinics.
Where can I have a XERF consultation in Daegu?
Miso Clinic is at 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, in front of Exit 1 of Kyungpook National University Hospital Station. +82-53-428-2700. Weekdays 11:00–19:00, Saturdays 10:00–16:00 (no lunch break); closed Sundays and public holidays.
Read next
- XERF lifting in Daegu: which skin it suits
- Which skin types suit XERF?
- XERF interval: how many months apart?
- Density and XERF: why some say “no effect”
- How long do XERF results last?
- What it means that Miso Clinic is a XERF ambassador
- XERF side effects, read as a timeline
- XERF in Daegu: what the device is and does
Product pages
Related: XERF product information
Who wrote this
Written and reviewed by Lee Chi-Hak, MD, director of Miso Clinic, Daegu. The treatment standards and injection design set out here are the ones we use in practice.
| Medical director | Lee Chi-Hak, MD |
|---|---|
| Address | 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea · Exit 1, Kyungpook National University Hospital Station |
| Phone | +82-53-428-2700 |
| Hours | Weekdays 11:00–19:00 (lunch 13:00–14:00) / Saturday 10:00–16:00 (no lunch break) / Closed Sundays and public holidays |
| Columns | All clinical columns |
| Reference library | All booster and device references |
References
- Three XERF human studies — Hwang JK, Medical Lasers 2025;14(1):23–30 (20 people · one session · 12 weeks) · Weiss RA et al., Cureus 2026;18(3):e104546, PMID 41930066 (39 people · two sessions · 90 days, manufacturer supported) · Erlich G et al., Lasers Med Sci 2026;41(1), PMID 42611100 (retrospective, 16 people · one session · 3 months). None of the three has a control group.
- XERF specifications — Lutronic published data: monopolar, 6.78 MHz plus 2 MHz, handpieces i05 (5×10 mm · 400 shots) · i10 (10×10 mm · 300 shots) · E40 (20×20 mm · 600 shots) · E60 (20×30 mm · 600 shots). In Korea it is approved in the general-purpose electrosurgical unit class; its advertising pre-screening mark is “General-purpose electrosurgical unit combination-2024-16-054”.
- XERF US 510(k) — FDA K251327 (2025-08-11). The indication is electrocoagulation and haemostasis, and no clinical tests were submitted. In Korea the device is approved in the general-purpose electrosurgical unit class.
- XERF heating by frequency — Ko K et al., Lasers Med Sci 2025, PMID 41315066. Computer simulation · porcine tissue. 2 MHz heated the fat layer broadly and deeply; 6.78 MHz heated locally along the fibrous septa. Most authors work for the manufacturer, and it is not a human study.
- Evidence for comparing radiofrequency devices — Aesthetic Surgery Journal Open Forum 2026 systematic analysis of the literature (15 studies · 1,230 people, one randomised controlled trial). It states that no direct device-to-device comparison was identified.
- Timeline of RF results — Cosmetics 2024;11(3):71 (20 Korean women: clinical assessment not significant at 4 weeks · significant at 12 and 24 weeks; device-measured elasticity from 4 weeks) · Weiss 2026 (84.6% at 30 days → 92.3% at 90 days) · Fitzpatrick 2003 and Edwards AF et al., Dermatol Surg 2013;39:104–110 (peak at 4–6 months). None has a control group.
- Improvement rates that depend on the rater — analysis of 16 ultrasound lifting studies (IJERPH 2023;20(2):1522): at 90 days, practitioners 92% vs patients 42%. Werschler 2016 (20 subjects): at one year, blinded assessment 43% vs patient satisfaction 95–100%; quantified lift was greatest at 90 days and fell to 22–33% at one year.
- Ulthera randomised trial with an untreated control — NCT04795622 (registered by the manufacturer Merz and others; results posted). Five centres in China, 101 treated vs 100 untreated, one session, 90 days. Blinded photo assessment 54.2% vs 47.0%, odds ratio 1.3545 (95% confidence interval 0.7530–2.4365) — not statistically significant. Unblinded investigator assessment 96.8% · patient assessment 94.7%.
- Fat-reduction indications and clinical submission — US 510(k) K180709 (a body-contouring device) included fat and circumference reduction in its indication and submitted two clinical studies. XERF’s K251327 has no such indication and submitted no clinical data.
- Timing and frequency of RF adverse reactions (older device) — Fitzpatrick R et al., Lasers Surg Med 2003;33:232–242 (86 subjects): blistering 2.3% immediately · 3.8% within 72 hours; second-degree burns in 21 of 5,858 treatments (0.36%) — figures for the 2002 high-energy single-pass technique, not a current incidence.
- Fat atrophy — Narins RS et al., Dermatol Surg 2006;32:115–124. Appears at 1–4 months (mean 2 months), about 4 per 10,000 treatments. Notes that heavy anaesthesia blocks pain feedback.
- Course of redness — Fitzpatrick 2003 (periorbital, 86 subjects): redness 36.0% immediately → 16.7% at 72 hours → 3.9% at one month. Two clinical trials of non-invasive RF (Wanitphakdeedecha 2022 · Imaizumi 2026) advised immediate return to normal activity and usual cosmetics, with zero cases of pigmentation.
- Approval numbers and advertising pre-screening numbers — MFDS medical device approval and prior screening of medical advertising are separate procedures. For example, “General-purpose electrosurgical unit combination-2024-16-054” on XERF promotional material is an advertising pre-screening mark.
- Medical advertising law — Medical Service Act of Korea, Article 56(2), which prohibits testimonial advertising, comparison with other clinics, superlative claims and advertising that guarantees or implies a guaranteed treatment effect.
- Miso Clinic practice guidance — indication criteria, site-by-site design, and the explanation and consent procedure. This is the source for every sentence marked as clinical judgement.
Everything in this column is general information and does not replace medical diagnosis or treatment. Effects and side effects vary with individual skin condition, age and underlying illness, and the same result is not guaranteed for everyone. Any decision to proceed should be made in an in-person consultation with a physician.
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