Oligio Kiss vs Density vs XERF in Daegu — choosing by skin thickness and sagging
Miso Clinic has three lifting devices, so we often hear “Which of the three is best?” The honest answer is that no study has compared the three devices in people under the same conditions. What we can tell you is how their designs differ and which we consider first for which face.
The short answer
The data cannot rank the three devices; the choice starts from the condition of the face. When loss of skin firmness and sagging of deeper layers are both present, we consider Oligio Kiss (RF + focused ultrasound) first; when the skin is thicker and the sagging deeper, Density (sequential monopolar → bipolar RF); when avoiding anaesthesia and returning to normal the same day matter most, XERF (monopolar RF at two frequencies) (clinical judgement). Published human studies number one for Density (16 people) and three for XERF (20, 39 and 16 people); for Oligio Kiss itself we could not find any, and none of them has a control group.
How do the three devices differ in design?
| Item | Oligio Kiss | Density | XERF |
|---|---|---|---|
| Manufacturer | Wontech | Jeisys Medical | Lutronic |
| Energy | Monopolar RF + focused ultrasound | Sequential monopolar → bipolar RF | Monopolar RF |
| What is combined | Type of energy | Polarity | Frequency (6.78 MHz + 2 MHz) |
| Tips · cartridges | RF tip + ultrasound cartridges with set depths | ALPHA · Eye · Face · Body | i05 · i10 · E40 · E60 |
| Korean approval | Approved name The Great RF Sonata (2023-09-01) | MFDS-approved medical device | MFDS-approved (general-purpose electrosurgical unit) |
| United States | Not found | Not found | 510(k) K251327 — indication electrocoagulation · haemostasis |
A difference in design is not a difference in results. “Two energies go deeper”, “two polarities cover more” and “two frequencies go deeper” come from mechanism and manufacturer material; the link to a better result on a human face has not been shown for any of the three.
Published studies and pain scores
| Device | Study | Reported result | Limits |
|---|---|---|---|
| Oligio Kiss | No study of the device itself found | For the class: monopolar RF, 20 people · significant jawline improvement at 12 weeks | Not data on this device · no control group |
| Density | Oku 2025 · 16 people · one session · 24 weeks | 3D imaging tightening 0.82 mm; pain 1.4/5 | No control group · single clinic |
| XERF | Hwang 2025 · 20 people · 12 weeks | Blinded raters identified the post-treatment photo 80%; VAS 4–5 without anaesthesia | No control group · not indexed in PubMed |
| XERF | Weiss 2026 · 39 people · two sessions · 90 days | GAIS 3 or above by treating physician 92.3%; pain 4.2/10 without anaesthesia | Unblinded · manufacturer support |
| XERF | Erlich 2026 · retrospective, 16 people | Pain 4.31 without anaesthesia; 12% scored 7 or more | Retrospective · no superiority conclusion possible (authors) |
These numbers cannot be set against each other. 0.82 mm is a distance measured on imaging, 92.3% is the share the treating doctor judged improved, and the pain scores mix 5-point and 10-point scales. Even widening the view to all RF devices, the 2026 systematic review found one randomised controlled trial among 15 studies and 1,230 subjects.
Focused ultrasound brings a sharp sensation each time a coagulation point forms, so its pain burden tends to be greater than RF alone. We take this into account when ultrasound is used with Oligio Kiss.
Choosing by skin thickness and sagging
Facial layer thickness varies greatly between people. Superficial fat measured 5.2 ± 1.9 mm with large individual variation, and sagging areas under the jaw had thinner skin and thicker superficial fat. The table below is not a study result but clinical judgement starting from these conditions.
| This face | Consider first | Why |
|---|---|---|
| Skin has thinned and the jawline has blurred too | Oligio Kiss | Broad heating + coagulation points at a specific depth together |
| Thicker skin, deep sagging of cheeks and jawline | Density | Designed to treat deep and shallow layers in sequence |
| No anaesthesia burden, 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 | Tips for small areas |
| Found a previous device’s pain hard going | Try a different device | Pain varies widely between people |
| Hollow cheeks or temples | None of the three first | Heat does not create volume |
Is it all right to have the three devices on top of each other?
There are no data showing that combining devices beats a single device. All three treat the same layers with heat, so Miso Clinic does not recommend plans that stack them on the same area on the same day. This is clinical judgement.
We found no evidence against switching devices as such. After the two to three months needed to judge the previous treatment, we decide the next device from the state of the face; telling us the area, shot count and pain of your previous treatment helps with the settings.
Summary
What is established
- Oligio Kiss = RF + focused ultrasound; Density = sequential polarity; XERF = monopolar at two frequencies
- Human studies: Density one study of 16 people · XERF three studies of 20, 39 and 16 people — none with a control group
- The indication of XERF’s US 510(k) is electrocoagulation and haemostasis
What we could not find
- A direct comparison of the three devices in people — not a single one
- A published clinical trial of Oligio Kiss itself
- Long-term duration for any of the three devices
Oligio Kiss, Density and XERF: frequently asked questions
Which is best: Oligio Kiss, Density or XERF?
No study has compared the three devices directly in people, so there is no basis for naming the best. We decide which device to consider first from skin thickness, depth of sagging, whether loss of firmness is also present, and the anaesthesia burden.
Which of the three hurts least?
No study has compared pain under the same conditions. The Density study reported a mean of 1.4 on a 5-point scale and the XERF studies means in the fours on a 10-point scale without anaesthesia, but the scales and conditions differ and cannot be compared. Oligio Kiss used with focused ultrasound tends to be a greater burden than RF alone.
Are all three devices approved by the MFDS?
All three are medical devices approved in Korea. Oligio Kiss’s approved name is The Great RF Sonata (2023-09-01), and XERF’s approved product class is general-purpose electrosurgical unit. We could not find the approval numbers of Density and XERF in the original record.
How long do results from the three devices last?
The longest follow-up in published studies is 24 weeks for Density and 90 days for XERF, and Oligio Kiss has no data on the device itself. Beyond that there are no human data on duration, so results are judged from the state of the face two to three months later.
Does a device with more shots work better?
A shot is a pulse unit defined for each tip, so if tip areas differ, the same number of shots heats a different area. Comparing shot counts between devices does not hold.
Read next
- Density vs XERF in Daegu: which is better?
- Oligio Kiss in Daegu — why radiofrequency and ultrasound are used together
- Density and Oligio — before comparing, settle which Oligio
- How many shots — what the number ‘shots’ really is
- Jawline sagging in Daegu — the order for choosing lifting devices and boosters
Product pages
Device references: Oligio Kiss · Density · XERF
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
- Oligio Kiss approval — Korean MFDS (Ministry of Food and Drug Safety) medical device approval record. Product name The Great RF Sonata (Wontech), approved 1 September 2023. ‘Oligio Kiss’ is the market name; Korean launch February 2024 (Wontech product information). Composition: monopolar radiofrequency (Oligio) + focused ultrasound (Ultraskin Tightan).
- Density human study — Oku K, J Cosmet Dermatol 2025;24(10):e70504, PMID 41090512. 16 adults · one session · 24 weeks · no control group. 3D imaging tightening distance 0.82 ± 0.36 mm; pain 1.4 ± 0.6 (5-point scale).
- 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 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.
- Evidence comparing RF devices — Aesthetic Surgery Journal Open Forum 2026 systematic review (15 studies · 1,230 subjects, one randomised controlled trial). It states explicitly that no direct device-to-device comparison was found.
- Individual 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.
- Ultrasound of lower-face layers — Kwon SH et al., Dermatologic Surgery 2022;48(5):527–531, PMID 35093961. Retrospective review of 200 people. Sagging areas under the jaw had thinner skin and thicker superficial fat.
- Medical advertising law — Korea’s Medical Service Act, Article 56(2). It prohibits advertising through treatment testimonials, comparison with other medical institutions, superlative claims and similar.
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.