Density versus XERF: what is the difference?
We have both, so we hear “which is better?” every day. The honest answer is “never compared”, but that does not mean there is nothing to go on.
The short answer
Density and XERF have never been compared directly in humans. A 2026 systematic review states that no head-to-head between RF devices was identified. Both are described as “using two things”, but the axis differs: Density combines two polarities (monopolar then bipolar); XERF combines two frequencies (6.78 and 2 MHz, monopolar). Miso Clinic tends to put thicker skin with deeper sagging on Density, and no-downtime, zone-by-zone precision on XERF, but that is clinical judgement, not data.
In one table
| Density | XERF | |
|---|---|---|
| Maker | Jeisys Medical | Lutronic |
| Mode | Monopolar → bipolar in sequence | Monopolar |
| Frequency | 6.78 MHz | 6.78 + 2 MHz |
| Axis combined | Polarity | Frequency |
| Max output | 400 W | Not in published specs |
| Surface protection | Five-level gas cooling | Cryogen spray |
| Output correction | RIC automatic impedance | Impedance feedback |
| Tips / handpieces | Four | Four |
| US FDA | Not found | 510(k) K251327 (2025-08) |
| Human data | 16 people, 3D 0.82 mm | 20, 39 and 16 people, all single-arm |
| Control group | None | None |
| Anaesthetic | By condition | Usually not needed |
Switching polarity versus switching frequency
Polarity changes whether current passes through the body: monopolar deep and broad, bipolar shallow and predictable. Density sends both in sequence within one pass to reach different depths at once.
Frequency changes where heat concentrates in tissue. Modelling and porcine histology showed 2 MHz heating the fat layer broadly and deep, 6.78 MHz heating locally along the fibrous septa. XERF chooses between them by zone.
They sound alike but change different things. And which design gives the better result has never been compared in humans.
How Miso Clinic places them
- Thicker skin, somewhat deeper sagging → Density first
- No downtime, no anaesthetic, zone-by-zone precision → XERF first
- One was hard to tolerate before → try the other
- This is clinical judgement, not data. Both have thin, uncontrolled human data.
Which treatment fits which concern
| Concern | Treatments to consider | Why |
|---|---|---|
| Thicker skin, deeper sagging | Density | Judgement — no comparison data |
| No downtime, zone-by-zone | XERF | Usually no anaesthetic |
| Narrow zones such as eyes | XERF i05 or Density Eye tip | Both have a dedicated tip |
| Thin skin, mild sagging | Booster class first | Not the RF layer |
| Hollow cheeks | Filler class | Neither |
Which treatment is “best” is decided by the state of your skin right now, not by the product. In consultation we look first at what has been lost and what is still there, before we talk about any product name.
Frequently asked questions
Which hurts more?
No comparison data. Both cool the surface and correct for impedance, and both use heat feedback as the endpoint.
Better results if I have both?
No data says so. It would heat the same layer twice, so we advise against it.
Which lasts longer?
Neither has long-term follow-up. XERF to 90 days, Density a short-term measurement.
Read next
If you want to go deeper
Product page
Who wrote this
Written and reviewed by Lee Chi-Hak, MD, medical director of Miso Clinic in Daegu, South Korea. Studies are cited with their size and limitations, and where we could not find data we say so. Individual decisions need an in-person examination; this page does not replace one.
| 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 |
| KakaoTalk | Miso Clinic channel |
| Hours | Weekdays 11:00–19:00 (lunch 13:00–14:00) / Saturday 10:00–16:00 / Closed Sundays and public holidays |
| Treatment guides | All guides |
| Comparisons | All comparisons |
| Columns | All clinical columns |
| Reference library | All booster and device references |
References
- Jeisys Medical, Density product material — sequential monopolar → bipolar RF, 6.78 MHz, up to 400 W, RIC impedance correction, five-level gas cooling, four tips (ALPHA, Eye, Face, Body). MFDS-approved medical device.
- Density human study — 16 people, 3D measurement 0.82 ± 0.36 mm, no control group.
- 2026 systematic review (15 studies, 1,230 people, one RCT) — states that no head-to-head comparison between RF devices was identified.
- Lutronic XERF product material — monopolar RF, 6.78 MHz + 2 MHz, four handpieces (XERF i05, i10; EFFECTOR E40, E60). MFDS-approved device. US FDA 510(k) K251327 (2025-08-11).
- XERF human studies, three — 20 people single-arm 12 weeks (Medical Lasers 2025), 39 people multicentre 90 days (Cureus 2026, manufacturer-supported), 16 people retrospective 3 months (Lasers Med Sci 2026). No control group in any.
Everything on this page 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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