Choosing between Density and XERF in Daegu: what to check and how to decide
“Where does Density best in Daegu?” and “where does XERF best?” are questions public data cannot settle. So this column sets out what you can check for yourself in a consultation when you are weighing the two devices.
The short answer
What to check when choosing Density or XERF is less the device name than what will be done to your face, with which tip, over how many sessions. There is no public measure of clinician skill; under Korean medical advertising law, reviews cannot be offered as evidence of results; and procedure counts are not the same as expertise. So when choosing Density or XERF in Daegu, we suggest checking: (1) whether your concern is one RF treats, (2) which tip, on which area, how many shots, (3) how many sessions the plan assumes, (4) who scored any results quoted, (5) whether approval wording such as “FDA approved” is accurate, and (6) whether you are told why it might not suit you. That neither device has a controlled human study is the same wherever you are treated.
What to check when you are considering both Density and XERF
If you are torn between Density and XERF, it helps to settle these five things before comparing the devices. Without them, switching the device name just brings you back to the same question.
- Check 1Is the concern one RF treats?Density and XERF are mainly for a facial contour that has started to sag. Volume loss, thin dull skin and pigmentation are not first for either. Sometimes both drop out here.
- Check 2Do the shot counts mean the same thing?A “shot” is a pulse count fixed to a tip. In just two XERF studies, one used a single large tip for a mean of 568.8 shots per session, the other split 600 shots across three tip sizes. If shot counts do not mean the same treatment within one device, they certainly cannot be compared between Density and XERF.
- Check 3How many sessions does the plan assume?The XERF studies mix one session (20 and 16 subjects) and two (39 subjects, four weeks apart); the Density study used one. Neither device has a study randomising the number of sessions.
- Check 4Does the plan stack both devices?There is no evidence that combining Density and XERF beats either one. Both heat the same layers, so if a plan puts both on the same area on the same day, ask why.
- Check 5What is already in your face and bodyImplanted electronic devices such as pacemakers (Density and XERF both use monopolar RF, which passes current through the body), metal implants in the area, non-dissolvable filler, and recent treatments — have these ready before consultation.
If you have had Density or XERF before, noting what you remember — area, tip, shot count, pain, how it felt a few months later — gives the most useful material for the next decision. Having tried both is still not evidence that one is better: timing, skin condition and settings were different.
What matters when choosing Density or XERF in Daegu
With no public measure of clinician skill, the yardstick is how specific and accurate the explanation in consultation is. Reviews cannot be used as evidence of results under Korean medical advertising law, and procedure counts are not expertise. These criteria apply wherever you choose Density or XERF, not only in Daegu.
| Criterion | Question to ask | What a specific answer looks like |
|---|---|---|
| Layer assessment | Is my concern sagging, thinning skin or volume? | Explains what has been lost area by area, including where RF does not fit |
| Tip, area, shots | Which tip, on which area, how many shots? | Gives the split by tip and area, not just a total |
| Sessions | How many sessions does this plan assume? | Says whether the session count rests on studies or clinical experience |
| Result figures | Who scored that figure? | Distinguishes blinded raters, the treating doctor and patient self-rating, and says whether there was a control group |
| Approval wording | Is it FDA approved? | Says accurately that XERF has 510(k) clearance with an indication of electrocoagulation and haemostasis |
| Durability | How long will it last? | Says follow-up runs to 24 weeks (Density) and 90 days (XERF) and anything beyond is experience |
| When not to | Is there a reason you would not recommend it for me? | Names the limits first, such as volume loss or severe sagging |
Price is not among these criteria; Miso Clinic does not discuss costs in its columns or on its website, and they are explained at consultation. That a product approval number and an advertising pre-review number are different things is explained in Is it an MFDS-approved product?; what a “shot” actually is, in How many shots of RF should I have.
How Miso Clinic decides
- We do not rank Density against XERF. We say plainly that there is one Density study (16 subjects) and three XERF studies (20, 39 and 16), none controlled.
- We sort the layer first. Sagging, thinning skin or volume loss, area by area — and we say first when both devices drop out.
- We separate data from clinical judgement. Considering Density first for thicker skin and deeper sagging, and XERF first when anaesthesia and area-by-area work matter, is clinical judgement.
- We write shot counts down by tip and by area.
- We review results together two to three months later, not from the tightness the next day.
- We do not use reviews or before-and-after photos as evidence, and we do not ask for a decision on the day.
The design, results and pain of the two devices are compared in Density vs XERF in Daegu: which is better?; fit by concern is in Sagging or loss of firmness: is Density or XERF the better fit?
Summary
What is established
- There is no public metric comparing clinician skill
- Even the XERF studies differed in shots, tips and sessions (mean 568.8 shots, one large tip, two sessions versus 600 shots, three tips, one session)
- The XERF US 510(k) indication is electrocoagulation and haemostasis, with no clinical tests submitted
- Korea’s Medical Service Act, Article 56, prohibits testimonial advertising and comparison with other clinics
What we could not find
- Any study comparing Density and XERF directly — none
- A randomised comparison of shot counts or session numbers
- Evidence that combining the two beats either one
- The Korean approval numbers of either device in the original record
Frequently asked questions
Which clinic in Daegu does Density or XERF best?
There is no public measure of clinician skill, so the data cannot answer that. Reviews cannot serve as evidence of results under Korean medical advertising law, and procedure counts are not expertise. Instead, ask “which tip, on which area, how many shots?”, “how many sessions does the plan assume?” and “is there a reason you would not recommend it for me?”, and choose a clinic that explains the limits in specific terms.
Can I have Density and XERF on the same day?
There is no evidence that combining the two beats either one. Both heat the same layers, so Miso Clinic does not recommend having both on the same area on the same day. That is clinical judgement.
I had Density last time. Can I have XERF next?
We found no evidence against switching devices. No study has compared intervals between them, so Miso Clinic waits the two to three months needed to judge the previous treatment and then chooses the next device from the state of the face. Telling us the area, shot count and pain from last time helps with settings.
Do more shots mean better results?
No human study has randomised shot counts for Density or for XERF. A shot is a pulse count fixed to a tip, so with different tip sizes the same count covers a different heated area. Shot counts alone cannot compare clinics.
I heard XERF is FDA approved.
What XERF has in the US is 510(k) clearance (K251327, 11 August 2025). A 510(k) is a finding of substantial equivalence to an existing device; the indication is electrocoagulation and haemostasis, and no clinical tests were submitted. 21 CFR 807.97 treats presenting 510(k) clearance as approval as misbranding.
Are Density and XERF approved in Korea?
Both are medical devices approved by Korea’s Ministry of Food and Drug Safety. We could not verify the published approval number for either. A number in an advertisement may be the medical advertising pre-review number, which is a different procedure from product approval.
What should I prepare before consultation?
The devices and dates of any previous RF or ultrasound treatment, the shot counts and pain you remember, current medication, any implanted electronic device or metal implant, filler history, and the area that bothers you most.
Read next
- Density vs XERF in Daegu: which is better? Results, differences and who each suits
- Sagging or loss of firmness: is Density or XERF the better fit?
- Looking into XERF in Daegu — filling in the material we had missed
- How many shots — what the number ‘shots’ really is
- Five things to check before a lifting treatment
- What to tell your doctor before treatment
Product pages
The devices themselves are set out here. Density: monopolar and bipolar RF in turn · XERF: monopolar radiofrequency lifting
Who wrote this
Written and reviewed by Lee Chi-Hak, MD, medical director of Miso Clinic in Daegu, South Korea. Every study cited above is given together with its design, its size and the limitations the authors themselves recorded, and where we could not find data, we have said that we could not find any.
| 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 — 39 subjects, United States — Weiss RA, Wang J, DiBernardo B, Bhatia AC, Cureus 2026;18(3):e104546, PMID 41930066, DOI 10.7759/cureus.104546. Four sites; 39 subjects (mean age 54.4); two sessions four weeks apart; 90 days. GAIS of 3 or more as rated by the treating investigator: 84.6% at 30 days, 92.3% (36/39) at 90 days; mean pain without anaesthesia 4.2/10; mean 568.8 shots per session with one large tip. No control group, unblinded, device and study support from the manufacturer.
- XERF — 16 subjects, retrospective — Erlich G, Dahan E, Wolf Y, Lasers Med Sci 2026;41(1), PMID 42611100, DOI 10.1007/s10103-026-04996-0. 16 women; one session; three months; 600 shots split across three tip sizes. Pain without anaesthesia 4.31 ± 1.71 (3 or less 38%, 4–6 50%, 7 or more 12%); brow and eyelid 3D measurements +1.11 to 1.44 mm (the right lateral canthus value was not significant). Retrospective, no control group; the authors state no conclusion can be drawn on superiority over single-frequency devices.
- XERF — 20 subjects, Korea — Hwang JK, Medical Lasers 2025;14(1):23–30, DOI 10.25289/ML.24.035. Single centre; 20 subjects aged 28–63, Fitzpatrick III–IV; one session; 12 weeks. Blinded raters picked the post-treatment photo correctly 80% of the time, GAIS 2.75/4, satisfaction 7.84/10, pain without anaesthesia VAS 4 in nine and 5 in eleven, no adverse events. No control group. The journal is indexed in KCI and KoreaMed, not PubMed/MEDLINE or SCIE.
- Density (sequential monopolar–bipolar RF) — Oku K, J Cosmet Dermatol 2025;24(10):e70504, PMID 41090512, DOI 10.1111/jocd.70504. Single clinic in Japan, single author; 16 adults aged 36–59, Fitzpatrick II–IV; one session; 24 weeks. Skin tightening distance on 3D imaging 0.82 ± 0.36 mm, lower-face tissue thickness reduction 0.89 ± 0.40 mm, 15 of 16 improved on GAIS, procedural pain 1.4 ± 0.6 on a 5-point scale, no severe adverse events. No control group. The abstract names the technology (sequential monopolar and bipolar pulsed RF) rather than the device.
- XERF US 510(k) — FDA K251327 (decision 11 August 2025). The summary states that no clinical tests were included in the submission; the indication is electrocoagulation and haemostasis in dermatologic and general surgical procedures. 21 CFR 807.97 states that 510(k) clearance does not denote official approval and that representing it as approval is misbranding.
- No device-to-device evidence — systematic review, Aesthetic Surgery Journal Open Forum 2026 (2015–2025; 15 studies, 1,230 subjects; one randomised controlled trial). No meta-analysis because of heterogeneity; no direct comparisons between devices were identified.
- When RF results are judged — Shin J et al., Cosmetics 2024;11(3):71, DOI 10.3390/cosmetics11030071. Oligio device; 20 Korean women; rater-blinded single arm. Clinician assessment was not significant at four weeks and significant at 12 and 24 weeks. No control group, and not a Density or XERF study.
- Korean medical advertising law — Medical Service Act, Article 56(2), prohibits advertising through patient testimonials, comparison with other clinics and superlatives. That is why this column carries no “best” claims, no clinic comparisons and no prices.
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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