XERF for cheek sagging: does it fit? — First tell sagging from hollowing
“My cheeks have sagged, so I would like XERF.” Within this sentence two different things are often mixed: sagging, where tissue has moved downwards, and hollowing, where volume has been lost. XERF fits the direction of the first; for the second, radiofrequency may not be the answer. This article sets out how to tell them apart and, once they are separated, where and how XERF is used.
The short answer
XERF for people with cheek sagging starts from one distinction: tightening with heat fits tissue that has descended (sagging), but lost volume (hollowing) is not filled by heat. When sagging and hollowing occur together, we place XERF on the lower sagging cheek · jawline, do not stack heat over the hollow front of the cheek, and deal with hollowing separately with the filler family (clinical judgement). The three XERF human studies all lack a control group, and the longest follow-up is about 3 months. Miso Clinic (4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea; +82-53-428-2700) compares sitting and lying positions to mark first where tissue has descended and where it has hollowed.
How do cheek sagging and cheek hollowing differ?
Different changes are contained in the words “my cheeks have sagged”. Which method fits the direction depends on what has changed.
| What has changed | What shows on the surface | Method that fits the direction |
|---|---|---|
| Tissue has moved downwards (sagging) | Fullness beside the nasolabial fold, a blurred jawline | Tightening or pulling — radiofrequency such as XERF · thread lifting |
| Volume has been lost (hollowing) | Hollow front cheeks · temples, with shadow | Filling — the filler family |
| The dermis has thinned | Texture breaks down, light reflects unevenly | The skin booster family |
| The supporting structure has receded | The midface looks flat | Reinforcement — the filler family |
It is common for all four to be mixed in one face. An article going deeper into sagging is Cheek sagging: what has descended, and on the filling side, Fillers in Daegu: the site decides the plane.
What does XERF do for cheek sagging?
XERF is a device that heats and tightens the dermis and the tissue beneath it with monopolar radiofrequency (6.78 MHz + 2 MHz). The lower cheek · jawline, where descended tissue is the main problem, is where XERF fits the direction (clinical judgement).
| Study | Set-up | Follow-up | Results |
|---|---|---|---|
| Hwang 2025 | 20 women · 1 session | 12 weeks | Blinded assessors identified photographs 80%, mean GAIS 2.75/4 |
| Weiss 2026 | 39 people · 2 sessions · E60 alone, mean 568.8 shots · 56.4 kJ | 90 days | Improvement 84.6% at 30 days → 92.3% at 90 days (manufacturer support) |
| Erlich 2026 | Retrospective, 16 people · 1 session · E60 300 + E10 200 + E5 100 shots | 3 months | Lower face 24–36 kJ |
None of the three studies has a control group, so we cannot promise in figures “how far cheek sagging will lift”. We could not identify a XERF study that reported results for cheek sagging separately either. There are also no data on maintenance beyond a year.
What happens if a hollow-cheeked face has XERF alone?
First, heat does not fill volume. Volume already lost remains, and as the sagging tissue is tidied up, the hollow areas above can actually look more exposed (clinical judgement).
Second, fat atrophy. If radiofrequency heat goes excessively into fat, one spot can sink 1–4 months (mean 2 months) after treatment, reported at about 4 per 10,000 treatments (Narins 2006). In cheeks that are already hollow, such a change can be more noticeable.
Third, the finding that XERF’s 2 MHz heats the fat layer broadly and deeply comes from computer simulation and porcine tissue (Ko 2025). A design of “heating fat to slim the cheeks” has not been confirmed in people. So Miso Clinic does not stack heat over the hollow front of the cheek (clinical judgement).
How are sagging and hollowing told apart in the consulting room?
- We compare sitting and lying positions. How far things return to place when lying down is a clue to “how much has descended”.
- We see how much the tissue moves. In a 25-person study of radiofrequency lifting, the single factor that predicted response was tissue mobility, and age was not significant (Sasaki 2007).
- We allow for individual variation in layer thickness. Superficial fat is 5.2 ± 1.9 mm and varies widely between people (Lee 2021), and sagging areas under the jaw had thinner skin and thicker superficial fat (Kwon 2022).
- We say first if it is beyond the range of non-surgical treatment. When the skin is lax enough to fold, we recommend a surgical consultation.
This order is Miso Clinic’s way of consulting (clinical judgement). Criteria for cheek sagging consultations are also set out in Cheek sagging: is there a scale?.
When sagging and hollowing occur together, how is the order decided?
- FirstMark where tissue has descended and where it has hollowedWe compare sitting · lying positions and map them out separately on the face.
- NextXERF for the sagging sideLower cheek · jawline with E40 · E60, narrow areas with the i10, avoiding the hollow front cheek.
- If neededFill the hollow sideWe consider reversible hyaluronic acid filler first, and decide on materials that appear gradually, such as Radiesse · Gouri · Juvelook, after seeing the response.
- After 3 monthsWe look at the face againIn RF studies, clinical assessment was not significant at 4 weeks and was significant at 12 · 24 weeks (Cosmetics 2024, no control group).
This order is not a formula set by research but Miso Clinic’s design, based on the goal, the schedule and whether a step can be reversed (clinical judgement). We could not identify a comparative study showing that “doing them together is better”. The reason for combining them is that they deal with different layers.
When does another method come before XERF?
| This kind of face | Consider first | Read next |
|---|---|---|
| Descended tissue is the main concern; you want to treat area by area | XERF | Which skin types XERF suits |
| Thick skin with fairly deep sagging | Density | XERF and Density: what is the difference? |
| Hollow front cheeks · temples are the main concern | The filler family first | Fillers in Daegu: the site decides the plane |
| The area below the jawline has broken down as well | Look separately at fat · sagging · muscle · bone | Jawline sagging and XERF |
| The position of sagging tissue needs to be moved | Consider absorbable thread lifting | Lifting for facial sagging: which layer |
Miso Clinic does not have Thermage, Ulthera or HIFU devices; we choose from XERF · Density · Oligio Kiss · absorbable thread lifting (mainly Hugel Blue Rose · HansBiomed MINT) · fillers · skin boosters. XERF in general continues in the hub article XERF lifting in Daegu: which skin it suits.
XERF for cheek sagging: frequently asked questions
Does XERF suit cheek sagging?
If sagging, where tissue has moved downwards, is the main concern, it fits the direction. If hollowing, where volume has been lost, is the main concern, heat does not fill it, so the filler family comes first.
Does XERF fill hollow cheeks?
No. Radiofrequency works by tightening tissue, so it cannot fill lost volume. Putting excessive heat into hollow cheeks can make fat atrophy more noticeable.
How can I tell whether it is sagging or hollowing?
We compare sitting and lying positions. How far things return when lying down is a clue to how much has descended. In the majority of faces the two are mixed, so we separate them by examination.
How long does XERF last for cheek sagging?
The longest follow-up in the XERF studies is about 3 months, and there are no data on maintenance beyond a year. None of the three studies has a control group.
Is it better to combine XERF and filler?
We could not identify a comparative study showing that combining them is better. Miso Clinic designs them together because sagging and hollowing are problems in different layers (clinical judgement).
Where can I have a XERF consultation for cheek sagging 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
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
- XERF specifications — Lutronic published data: monopolar, 6.78 MHz + 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 the device is approved in the general-purpose electrosurgical unit class; the mark “2024-16-054” seen on promotional material is a medical advertising pre-screening number, not an approval number.
- Three XERF human studies — Hwang JK, Medical Lasers 2025;14(1):23–30 (20 subjects · one session · 12 weeks) · Weiss RA et al., Cureus 2026;18(3):e104546, PMID 41930066 (39 subjects · two sessions · 90 days, manufacturer support) · Erlich G et al., Lasers Med Sci 2026;41(1), PMID 42611100 (retrospective, 16 subjects · one session · 3 months). None of the three has a control group.
- 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. The majority of the authors work for the manufacturer, and it is not a human study.
- 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.
- What predicted response — Sasaki G et al., Aesthetic Surg J 2007;27(4):376–387 (25 subjects, mean age 52.3, 12 months). Tissue mobility was the single significant factor; age was not a significant predictor. The sample is small.
- Variation in facial layer thickness — Lee KW et al., Clinical Anatomy 2021;34(7):1050–1058, PMID 33583088. 3D measurement of 30 embalmed cadavers: skin 2.1 ± 0.4 mm, superficial fat 5.2 ± 1.9 mm.
- Lower-face layers on ultrasound — Kwon SH et al., Dermatologic Surgery 2022;48(5):527–531, PMID 35093961. Retrospective analysis of 200 people. Sagging areas under the jaw had thinner skin and thicker superficial fat.
- 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.
- No device-to-device evidence — systematic analysis of the literature, Aesthetic Surgery Journal Open Forum 2026 (15 studies, 1,230 subjects; one randomised controlled trial). It states that no direct comparisons between devices were identified.
- 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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