Ulthera and Thermage vs Density and XERF — what is the same and what is different
“Can I have Density or XERF instead of Ulthera or Thermage?” First, a disclosure: Miso Clinic does not have Ulthera or Thermage. So this comparison is not written to recommend our own devices; it sets out, as they are, what the four devices share, how they differ and how deep the evidence goes.
The short answer
Ulthera uses focused ultrasound (HIFU) to create point-like coagulation spots at set depths, while Thermage, Density and XERF use radiofrequency (RF) to heat the dermis and the layers beneath it broadly. The evidence for Ulthera and Thermage is far deeper than for Density and XERF — Ulthera submitted clinical data from 7 studies and 167 people for its US 510(k) and also has a randomised trial with an untreated control. The Density (16 people) and XERF (75 people) data have no control group, and the indication of XERF’s 510(k) is electrocoagulation and haemostasis. No study has compared the four devices directly in people, so there is no basis for saying Density or XERF works “instead of” Ulthera or Thermage.
What energy do Ulthera, Thermage, Density and XERF use?
| Device | Energy | Shape of the heat | At Miso Clinic |
|---|---|---|---|
| Ulthera (Merz) | Focused ultrasound (HIFU), transducers 1.5 · 3.0 · 4.5 mm | Point-like coagulation spots at set depths | No |
| Thermage (Solta Medical) | Monopolar RF 6.78 MHz | Broad heating | No |
| Density (Jeisys Medical) | Sequential monopolar → bipolar RF | Different depths one after the other | Yes |
| XERF (Lutronic) | Monopolar RF 6.78 + 2 MHz | By area, via frequency and handpiece | Yes |
Miso Clinic has Oligio Kiss (RF + focused ultrasound), which includes focused ultrasound, but no trial has compared Oligio Kiss directly with Ulthera either.
How different is the evidence for Ulthera and Thermage versus Density and XERF?
| Device | US regulatory route · wording | Human data |
|---|---|---|
| Ulthera | 510(k) K243035 — indication for lifting eyebrow, submental and neck tissue; clinical data from 7 studies, 167 people submitted | One randomised trial with untreated control (blinded 54.2% vs 47.0%, not significant); meta-analysis of 42 studies |
| Thermage | Registered with the US FDA | Many studies, but most are uncontrolled observational studies or physician surveys |
| Density | Not found | One case series, 16 people, 24 weeks, no control group |
| XERF | 510(k) K251327 — indication electrocoagulation · haemostasis, no clinical data submitted | Three studies, 75 people, none with a control group |
Ulthera is the device with the deepest evidence in this category, and also a device where a difference was not statistically confirmed once a control group was used. The two statements do not contradict each other, and the 47% untreated-control figure applies just as much to the uncontrolled Density and XERF data.
How do pain and sensation differ between Ulthera, Thermage, Density and XERF?
| Device | Reported pain | Conditions |
|---|---|---|
| Ulthera and other focused ultrasound | Mean 4.85/10 (meta-analysis of 42 studies) | Face and neck 4.62, other areas 5.58 |
| Density | Mean 1.4/5 | 16 people · 5-point scale |
| XERF | Mean 4.2/10 | 39 people · no anaesthesia |
| Thermage | Endpoint is the patient’s sensation of heat (manufacturer manual) | No comparable figure found |
Because scales, anaesthesia and areas differ, these numbers cannot be turned into a claim that Ulthera, Thermage, Density or XERF hurts less. The main difference is that focused ultrasound such as Ulthera brings a sharp or aching jolt at each coagulation point, while RF such as Thermage, Density and XERF brings a rising sensation of heat.
If you want Ulthera or Thermage, and if you want Density or XERF
| What you want | Consider first | Why |
|---|---|---|
| The device with the deepest evidence | Ulthera · Thermage (not available at Miso Clinic) | We say so honestly |
| Deep-layer sagging treated point by point | Ulthera or Oligio Kiss | Focused ultrasound |
| Thicker skin, deep sagging, RF | Density | Sequential polarity design |
| No anaesthesia burden, same-day return, RF | XERF | Usually no anaesthesia |
| Lost volume · thin skin | None of Ulthera, Thermage, Density or XERF first | Filler · boosters |
If you want Ulthera or Thermage, the right step is to find a clinic that has that device, and Miso Clinic has no hesitation in telling you so.
Ulthera, Thermage, Density and XERF comparison summary
What is established
- Ulthera = focused ultrasound; Thermage, Density and XERF = radiofrequency
- Ulthera’s 510(k) has a lifting indication with clinical data submitted; XERF’s 510(k) is for electrocoagulation and haemostasis with no clinical data submitted
- Ulthera randomised trial with untreated control: 54.2% vs 47.0%, not statistically significant
What we could not find
- A direct comparison study between any of Ulthera, Thermage, Density and XERF
- A controlled study of Density or XERF
- The Korean MFDS product approval numbers for Ulthera and Thermage in the original record (MFDS is Korea’s Ministry of Food and Drug Safety, which approves medical devices)
Ulthera, Thermage, Density and XERF: frequently asked questions
Can I have Density or XERF instead of Ulthera?
Ulthera uses focused ultrasound and Density and XERF use radiofrequency, so the energy and the shape of the heat differ, and with no direct comparison study there is no basis for saying one works “instead of” the other. The evidence for Ulthera is far deeper.
Do Thermage, Density and XERF work on the same principle?
Thermage, Density and XERF all belong to the 6.78 MHz monopolar RF family. Density adds bipolar RF in sequence, and XERF adds 2 MHz and four handpieces. The body of evidence for Thermage is far larger, and no direct comparison study exists.
I heard there is a study showing Ulthera does not work?
In a randomised trial registered by the Ulthera manufacturer, blinded photo assessment found 54.2% improved in the treated group and 47.0% in the untreated control group, a difference that was not statistically significant. But this is one Ulthera trial with one session at 90 days, and it does not mean “proven not to work”.
Does Miso Clinic have Ulthera or Thermage?
No. Miso Clinic in Daegu does not have Ulthera or Thermage; its lifting devices are Density, XERF and Oligio Kiss (RF + focused ultrasound).
Which hurts less, Ulthera or Thermage?
No study has compared Ulthera and Thermage under the same conditions. The mean pain in a meta-analysis of 42 studies of Ulthera and other focused ultrasound was 4.85/10, and RF figures use different scales and anaesthesia, so the numbers cannot be set side by side.
Read next
- Ulthera (Ultherapy) — a device we do not have, and its evidence is thicker than ours
- How Density differs from Thermage
- XERF versus Thermage: the difference
- Focused ultrasound (HIFU) and radiofrequency (RF): how they differ
- Oligio Kiss, Density or XERF in Daegu
- Density lifting in Daegu: a complete guide
Product pages
Device references: Density · XERF · Oligio Kiss
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
- Ulthera US 510(k) — K243035 (2025-02-24). Indication wording includes lifting of eyebrow, submental and neck tissue; clinical data from 7 studies and 167 subjects were submitted. The indication of XERF’s K251327 is electrocoagulation and haemostasis, with no clinical data submitted.
- Ulthera randomised trial with an untreated control — NCT04795622 (registered by the manufacturer Merz and others; results posted). Five centres in China, 101 treated vs 100 untreated, one session, 90 days. Blinded photo assessment 54.2% vs 47.0%, odds ratio 1.3545 (95% confidence interval 0.7530–2.4365) — not statistically significant. Unblinded investigator assessment 96.8% · patient assessment 94.7%.
- Focused ultrasound meta-analysis — Amiri M et al., Aesthetic Surg J 2025;45(3):NP86–NP94. 42 studies (2 controlled trials), level of evidence 3. Practitioner-rated improvement 89% · patient-rated 84% · mean pain 4.85/10. Satisfaction was 62% vs 91% depending on whether a “neutral” option was offered.
- Thermage — Solta Medical, 6.78 MHz monopolar, device registered with the US FDA. There are many publications, but most are uncontrolled observational studies or physician surveys, and a 2020 international Delphi consensus noted that device-specific guidance is lacking. No study has compared it directly with Density or XERF. Miso Clinic does not have Thermage or Ulthera.
- 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.
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.