XERF: a monopolar radiofrequency platform, and what is actually known about it

Radiofrequency is not light. A laser works by being absorbed — by pigment, by water, by haemoglobin — and destroying a chosen target. RF instead pushes an alternating electrical current through tissue; charged molecules reverse direction with the current, and the friction produces heat. Because nothing is absorbing light, the constraints skin colour places on laser treatment apply much less here.

The heat is the whole point. Once tissue reaches a particular temperature range, collagen fibres partially unwind and contract immediately — what some patients feel as tightness on the day. Separately, the thermal insult switches on a repair response, and over the following weeks fibroblasts deposit new collagen. This is why radiofrequency treatments are assessed at two to three months, not on the day.

Monopolar and bipolar RF differ in where that heat ends up. In a bipolar device the current travels between two closely spaced electrodes, so energy stays relatively superficial. In a monopolar device the current leaves the handpiece, passes through the body and returns through a separate electrode placed elsewhere, travelling through a larger and deeper volume of tissue. Devices built for lifting are generally monopolar for that reason.

A question that comes up in almost every consultation is whether to have a skin booster or a lifting treatment, as though the two were alternatives. They are not really competing, because they address different layers. Injectable boosters place material into the dermis or alter how it behaves, targeting density and texture. Radiofrequency puts heat into the deeper structural layer and targets a contour that has begun to descend. So a patient whose skin is thin but whose contour is intact will be disappointed by lifting alone, and the reverse holds too.

Injections work on the material in the dermis and devices work on the structure below it — which means the useful question is not which is better, but whether the two can be planned together. Our comparison of six collagen and skin boosters covers the injectable side; our other RF platforms are documented under Density and Oligio Kiss.

XERF does not use a single frequency. It operates at 6.78 MHz and at 2 MHz. In radiofrequency generally, frequency influences how current distributes through tissue: lower frequencies tend to spread more deeply, higher frequencies tend to concentrate energy more superficially. The manufacturer describes the combination of these two frequencies as addressing three tiers of depth — superficial, intermediate and deep.

The four handpieces differ in contact area and maximum shot count. In practice the deciding question is whether a given tip can sit flat against a given part of the face. A large tip on a narrow, curved area makes poor contact; a small tip dragged across a broad cheek takes longer and delivers energy less evenly.

These figures are the manufacturer's published specifications. How many shots a given treatment uses depends on the area covered and the condition of the skin; a higher shot count is not in itself a better treatment.

Reasonable candidates

• Early to moderate laxity — a jawline losing definition, cheeks that sit lower than they did
• Patients who do not want surgery and cannot afford visible downtime
• Patients wanting firmness and texture addressed in the same session
• Patients uncomfortable with needle-based treatments
• Patients already treating the dermis with injectables whose contour has not changed

Where XERF alone will not get you there

• Hollow cheeks or temples — radiofrequency creates no volume
• Advanced laxity with actual folding of skin — that is surgical territory
• Thin, depleted dermis — injectables that supply material come first
• Melasma, redness or pore concerns as the principal complaint
• An implanted electronic device — pacemaker, implantable defibrillator — in which case RF is contraindicated as a rule
• Pregnancy, or active infection or broken skin at the treatment site
• Metal implants or substantial filler in the treatment area — tell us beforehand

This is the section that matters most, so it is set out in three parts.

1. Evidence for XERF specifically

Within the limits of our search, we found no published clinical trial results generated using XERF. That statement means what it says and no more: not that the device does not work, but that we cannot verify performance from published data. A great many aesthetic devices sold in Korea are in the same position. Being common does not make it something to leave out of a clinical reference.

2. The regulatory facts

XERF is approved as a medical device by Korea's Ministry of Food and Drug Safety (MFDS). Two points need stating precisely.

First, we could not find a published approval number. The number the manufacturer publishes is an advertising pre-review number — "General-purpose electrosurgical unit combination-2024-16-054", valid to 22 April 2027. An advertising review number is not an approval number. Korea requires medical advertising to be pre-screened; that screening examines the wording of the advertisement, while device approval examines the safety and performance of the device itself. Presenting the former as though it were the latter is not accurate.

Second, as that number shows, the approved device class is "general-purpose electrosurgical unit." The product is sold as a lifting device, but its regulatory category is a broad one covering equipment that delivers RF energy to tissue. It is not an individual finding about facial lifting. Patients should know that before choosing.

3. Evidence for monopolar radiofrequency as a class

There is published research on monopolar radiofrequency generally. It was not conducted with XERF, and its findings should not be transferred to XERF as though they were. We cite it here with that attribution made explicit.

Cosmetics 2024;11(3):71 reported on 20 healthy women (mean age 47.95±6.02, Fitzpatrick skin types III–IV, mild to moderate facial laxity) assessed at 4, 12 and 24 weeks after a single monopolar RF treatment. Reported findings:

• Statistically significant improvement in the jawline and nasolabial folds at 12 weeks (p<0.05)
• Increased cheek elasticity from week 4 (p<0.01), sustained to 24 weeks
• Mean pain during treatment of 0.4 out of 10
• No burns or scarring reported

Read alone, those are encouraging numbers. They should be read alongside the limitations the authors state themselves:

• No randomised control group — this was a prospective, evaluator-blinded cohort study
• Twenty participants, all female — too small and too narrow to generalise from
• No comparison against other anti-ageing technologies — so it supports no claim of superiority over anything

Put together: monopolar radiofrequency as an approach has small but consistent supporting evidence, and XERF as an individual device has no published evidence we could locate. We use XERF not because it is "clinically proven" — it would be untrue to say so — but because the mechanism of the class is well established and the range of handpiece sizes is genuinely useful across different regions of a face. We have no grounds to claim more.

The consultation starts by identifying which layer the visible change belongs to. If laxity dominates, radiofrequency is appropriate; if the dermis is thin and the texture poor, injectables come first. Both often apply, in which case we sequence them rather than combining everything into one visit.

Because RF passes current through the body, some history must be established before treatment. Please tell us about implanted electronic devices (pacemaker, defibrillator), metal implants, any filler or thread placement in the area, pregnancy, and skin disease. This is not a formality.

The session itself: the face is cleansed of makeup and oil, and a return electrode pad is placed so the current has a path back. Gel is applied to aid conduction and cooling, treatment zones are marked, and the handpieces are worked through in order — smaller tips for narrow regions, larger for broad ones. A full face takes roughly 40 minutes to an hour including preparation.

Power is not set to maximum at the start. We begin low and adjust against the heat you report feeling. If something feels hot rather than warm, say so immediately — that feedback is what the power setting is calibrated against.

Pain — the usual sensation is repeated warmth building to brief moments of heat. The class study cited above reported mean intra-procedural pain of 0.4/10, but that figure belongs to that study's conditions; what you feel depends heavily on power settings and individual sensitivity. Areas close to bone — forehead, jawline, temples — tend to register more sharply.

Downtime — most patients return to normal activity the same day. Redness immediately afterwards may not be fully concealable with makeup, so allow some margin if you have something important that evening.

For the first few days

• Cleanse gently with lukewarm water; do not rub the treated skin
• Avoid sauna, jjimjilbang, strenuous exercise and alcohol on the day
• Moisturise well and use sun protection diligently
• Postpone exfoliants and actives for several days
• Return to the clinic promptly if you notice unusual sensation or persistent pain

This reference was written and reviewed by Dr. Lee Chi-Hak, director of Miso Clinic in Daegu, South Korea. Alongside XERF the clinic operates two other radiofrequency platforms — Density and Oligio Kiss — and separately stocks six collagen and skin boosters that work on the dermis. Holding several devices is not a claim that any one is superior; it is that a clinic with a single device ends up using it on every face. Our other references are collected in the Miso Clinic reference library.