Density vs XERF in Daegu: which is better? Results, differences and who each suits
“Density or XERF — which is better?” Miso Clinic has both devices, so we hear this almost every day. The honest answer is that nobody has compared them in people. That does not leave you without a way to choose, so the design, the published results, the pain data and who each suits are set out side by side here.
The short answer
Whether Density or XERF is better cannot be answered from the data. No study has compared the two devices in people, and a 2026 systematic review (15 studies, 1,230 subjects) found no direct device-to-device comparisons. The biggest difference is design: Density combines polarity (monopolar, then bipolar), XERF combines frequency (6.78 MHz and 2 MHz). Human data amount to one Density study (16 subjects, 24 weeks) and three XERF studies (20, 39 and 16 subjects, up to 90 days), and none of the four has a control group. So at Miso Clinic the question is not which device is better but which to consider first for this face: Density when the skin is thicker and the sagging deeper, XERF when avoiding anaesthesia and treating area by area matters more. That is clinical judgement, not a study result.
Density and XERF: what is the biggest difference?
Density and XERF are both radiofrequency (RF) lifting devices that heat the deeper layers of the skin to provoke a collagen response, and both are described as “using two things”. The biggest difference is what they use two of: Density combines the way current flows (polarity), XERF combines the frequency of the current.
Density — monopolar, then bipolar
Density (Jeisys Medical) delivers monopolar RF and then bipolar RF within a single pulse. With monopolar there is one electrode, so current passes through the body to a return pad; with bipolar, current travels only in the narrow zone between two electrodes. The design aims to cover different depths in one pass. Published specifications: 6.78 MHz, up to 400 W, RIC impedance correction by area, five-level gas cooling, and a skin temperature display during treatment.
XERF — two frequencies, 6.78 MHz and 2 MHz
XERF (Lutronic) uses monopolar RF only, but at two frequencies. In a 2025 simulation and porcine histology study, most of whose authors work for the manufacturer, 2 MHz heated the fat layer broadly and deeply while 6.78 MHz heated locally along the fibrous septa. XERF cools the surface with cryogen spray, adjusts output by impedance feedback and switches between tips of different sizes by area.
| Item | Density | XERF |
|---|---|---|
| Manufacturer | Jeisys Medical, South Korea | Lutronic (Cynosure Lutronic), South Korea |
| Delivery | Monopolar → bipolar in sequence | Monopolar |
| Frequency | 6.78 MHz | 6.78 MHz + 2 MHz |
| What is combined | Polarity | Frequency |
| Maximum output | 400 W | Not found in published specifications |
| Epidermal protection | Gas cooling, five levels | Cryogen spray |
| Output correction | RIC impedance correction | Impedance feedback |
| Korea (MFDS) | Approved medical device (number not verified) | Approved medical device (number not verified) |
| US FDA | Not found | 510(k) K251327 (11 Aug 2025) — indication: electrocoagulation and haemostasis |
A difference in design is not a difference in results. “Two polarities cover more layers” and “two frequencies send heat deeper” come from mechanism and preclinical work. The step from there to “so the result on a human face is better” has not been shown for Density or for XERF. There is also work (all authors from the manufacturer) suggesting heating depth depends more on electrode size and spacing than on polarity itself.
How do the results of Density and XERF differ?
No study has measured Density and XERF against the same yardstick. Each device has its own human studies, and they measured different things with different designs, so the numbers cannot be lined up to rank the devices. Here is what each study actually reported, with its limits.
| Study | Device and design | Reported result | Limits |
|---|---|---|---|
| Oku 2025 (Japan) | Density (sequential mono–bipolar) · 16 subjects · 1 session · 24 weeks | 3D tightening 0.82 ± 0.36 mm; 15 of 16 improved | No control · single clinic · single author |
| Hwang 2025 (Korea) | XERF · 20 subjects · 1 session · 12 weeks | Blinded raters identified post photo 80%; GAIS 2.75/4 | No control · single centre · not in PubMed |
| Weiss 2026 (US) | XERF · 39 subjects at 4 sites · 2 sessions · 90 days | GAIS 3+ by treating investigator 92.3% at 90 days | No control · unblinded · manufacturer support |
| Erlich 2026 (Israel) | XERF · 16 subjects, retrospective · 1 session · 3 months | Brow and eyelid 3D +1.11 to 1.44 mm | Retrospective · no control · no superiority claim (authors) |
0.82 mm and 92.3% are not the same unit. The first is a distance measured on 3D imaging; the second is the share of people the treating doctor judged “improved”. Setting one against the other to say “Density is better” or “XERF is better” does not hold statistically. None of the four studies has a control group, so it is not possible to say how much of the observed change came from treatment. Across RF lifting as a whole, the 2026 systematic review found one randomised controlled trial among 15 studies and 1,230 subjects.
Both devices are judged at the same point
The tightness right after RF treatment is immediate collagen contraction and settles quickly; the change that lasts is remodelling over weeks to months. In an RF study of 20 Korean women with blinded raters (Oligio device), clinician assessment was not significant at four weeks and was significant at 12 and 24 weeks. So with Density or XERF alike, results are judged two to three months later, not the next day.
How long it lasts
The longest follow-up in the published studies is 24 weeks for Density and 90 days for XERF. Beyond that, neither device has human data. That RF lifting is often reviewed again at around six months to a year is clinical experience; the timing of a repeat is set by the face, not the calendar.
Density and XERF: how do pain and sensation differ?
No study has compared pain from Density and XERF under the same conditions. Each study reported its own numbers, but the scales and conditions differ, so they cannot be turned into “this one hurts less”.
| Device | Study | Reported pain | Conditions |
|---|---|---|---|
| Density | Oku 2025 · 16 | Mean 1.4 ± 0.6 | 5-point scale · anaesthesia not stated in the abstract |
| XERF | Hwang 2025 · 20 | VAS 4 in nine, 5 in eleven | 10-point scale · no anaesthesia |
| XERF | Weiss 2026 · 39 | Mean 4.2 | 10-point scale · no anaesthesia |
| XERF | Erlich 2026 · 16 | 4.31 ± 1.71 — two people (12%) scored 7 or more | 10-point scale · no anaesthesia |
Doubling Density’s 1.4 on a 5-point scale to compare it with XERF’s scores in the fours is not valid: the scales differ, and anaesthesia, treated area and output may all have differed. What can be said with confidence is this: without anaesthesia XERF averaged in the fours, yet two of 16 people scored 7 or more. An average does not describe everyone’s pain.
How it feels — Miso Clinic’s clinical experience
- Density — short surges of heat that rise and fade, felt more over bone or where skin is thin. Numbing cream is applied depending on area and settings.
- XERF — the surface is cooled with cryogen spray as treatment proceeds, usually without anaesthesia. Topical anaesthesia is added for people who are sensitive to pain.
- Both devices — the end point is the heat you feel. Heat that is hard to bear is not something to endure but a signal to tell us at once, and output and cooling are adjusted on the spot. Most people return to normal activities the same day; redness or warmth can last from a few hours to a day.
The descriptions above come from the consulting room, not from a comparative study.
Density or XERF: which to consider first, and for whom?
With no direct comparison, the choice starts from the face rather than the device name. The table below is the guide Miso Clinic uses in consultation, and it is clinical judgement, not a study result.
| Situation | Considered first | Why |
|---|---|---|
| Thicker skin, deeper sagging of cheeks and jawline | Density | Monopolar-then-bipolar design aims at deep and shallow layers in one pass — no comparative data |
| No anaesthesia wanted, same-day return matters | XERF | Usually done without anaesthesia |
| Narrow areas such as around the eyes or mouth | XERF small tip or Density Eye tip | Both devices have tips for small areas |
| Found one device too painful before | Try the other | Pain varies widely between people |
| Thin, dull skin is the main concern | Neither first — skin boosters | Not the layer RF targets |
| Hollow cheeks or temples (volume loss) | Neither — fillers | Tightening with heat can make hollows look deeper |
Which treatment is best is decided by the state of your skin now, not by the product. Guidance by concern, for sagging and for firmness, is in Sagging or loss of firmness: is Density or XERF the better fit?; what to check when choosing between the two in Daegu is in Choosing between Density and XERF in Daegu.
Summary
What is established
- Density and XERF combine different things — Density polarity (monopolar → bipolar), XERF frequency (6.78 MHz + 2 MHz)
- Human studies: one for Density (16 subjects, 24 weeks), three for XERF (20, 39 and 16 subjects, up to 90 days)
- Reported pain: Density 1.4/5; XERF without anaesthesia in the fours out of 10 — different scales, not comparable
- The XERF US 510(k) indication is electrocoagulation and haemostasis, with no clinical tests submitted
What we could not find
- Any study comparing Density and XERF in people — none
- A controlled study of either device
- Durability beyond 24 weeks or 90 days
- The Korean approval numbers of either device in the original record
Density vs XERF: frequently asked questions
Which is better, Density or XERF?
The data cannot answer that. No study has compared the two devices in people, and a 2026 systematic review found no direct device-to-device comparisons. Human studies number one for Density (16 subjects) and three for XERF (20, 39 and 16), all without a control group. Miso Clinic decides which to consider first from skin thickness, depth of sagging, how much anaesthesia matters and the area to be treated.
Density goes up to 400 W. Does that make it stronger than XERF?
Maximum output is the ceiling a device can deliver, not the energy that reaches the skin. Actual heating depends on frequency, electrode size and layout, pulse duration and tissue impedance together. Maximum output alone cannot compare Density and XERF, and XERF’s maximum output was not found in published specifications.
Is XERF FDA approved?
“Approved” is not accurate. XERF received US FDA 510(k) clearance on 11 August 2025 (K251327). A 510(k) is a finding of substantial equivalence to an existing device; this one’s indication is electrocoagulation and haemostasis rather than lifting, and no clinical tests were submitted. We could not find an FDA listing for Density.
Which hurts more, Density or XERF?
No study has compared them under the same conditions. The Density study reported a mean of 1.4 on a 5-point scale; three XERF studies reported means in the fours on a 10-point scale without anaesthesia. The scales and conditions differ, so the numbers cannot be compared. In the 16-person XERF study, two people scored 7 or more. If one device was hard going before, trying the other is a practical rule.
How long do Density and XERF results last?
The longest published follow-up is 24 weeks for Density and 90 days for XERF; beyond that neither device has human data. That RF lifting is often reviewed at around six months to a year is clinical experience. Results are judged two to three months after treatment.
Is it better to have both Density and XERF?
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.
At what age do people have Density or XERF?
It depends on the skin, not the age. Someone in their thirties whose jawline is starting to blur can be a candidate; someone in their fifties whose main problem is volume loss is not a Density or XERF case first.
How do Density and XERF compare in price?
Miso Clinic does not discuss costs in its columns or on its website. Costs are explained at consultation.
Read next
- Sagging or loss of firmness: is Density or XERF the better fit?
- Choosing between Density and XERF in Daegu: what to check
- Density and XERF — they combine along different axes (evidence in detail)
- Density, XERF and Oligio compared
- Density in Daegu: which face is it right for?
- XERF in Daegu: which face is it right for?
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
- 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 — 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.
- 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 heating by frequency — Ko K et al., Lasers Med Sci 2025, PMID 41315066. Finite-element simulation and porcine skin histology. 2 MHz heated the fat layer broadly and deeply; 6.78 MHz heated locally along the fibrous septa. Most authors are employees of the manufacturer (Cynosure Lutronic).
- Polarity and heating depth — J Biomed Sci Eng 2024. In finite-element analysis with tissue measurement, a widely spaced bipolar applicator heated 1.9 to 5.7 times deeper than a monopolar electrode. All authors are employees of that device’s manufacturer.
- 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.
- Density specifications — Jeisys Medical official material (jeisys.co.kr, densityrf.com): 6.78 MHz, monopolar then bipolar in sequence, up to 400 W, five-level gas spray cooling, RIC impedance correction, skin temperature display. Approved as a medical device by Korea’s Ministry of Food and Drug Safety (MFDS); we could not verify the approval number itself.
- XERF specifications — Cynosure Lutronic official material (cynosure.com/xerf): 6.78 MHz + 2 MHz, monopolar only, cryogen spray cooling, impedance feedback. Approved as a medical device by the MFDS; we could not verify the approval number itself.
- 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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