XERF vs Sofwave: depth is the real difference
Sofwave aims ultrasound at one layer, the mid-dermis about 1.5 mm down. XERF uses radiofrequency at two frequencies with three depth settings. Sofwave's FDA file covers wrinkles, a brow and neck lift, acne scars and more; XERF's covers electrocoagulation and hemostasis. Karisma offers XERF only, at $1,500 a session.
Published · Written by Kay Woodson · Results vary.XERF and Sofwave, line by line
From the FDA 510(k) files and each maker's site, checked October 29, 2026. Where a line is a maker's claim, it says so.
| XERF | Sofwave | |
|---|---|---|
| Maker | Lutronic Corporation (Cynosure Lutronic), Korea | Sofwave Medical Ltd., Israel |
| Energy | Monopolar radiofrequency | Ultrasound from an array of transducers, which the maker calls SUPERB |
| Frequency | 2 MHz and 6.78 MHz | 10 to 12 MHz |
| Where the heat goes | Shallow, middle and deep layers, per Cynosure | 0.5 to 2 mm, centered at 1.5 mm, per Sofwave |
| Surface cooling | Cryogen spray with each pulse | Built-in cooling the maker calls Sofcool |
| Latest FDA file | 510(k) K251327, August 11, 2025 | 510(k) K250146, April 18, 2025 |
| Cleared uses | Electrocoagulation and hemostasis in dermatologic and general surgical procedures | Facial lines and wrinkles; brow lift; lift of lax tissue under the chin and neck (age 22 and up); short-term improvement in the look of cellulite; acne scars; skin laxity on the upper arms |
| Needles | No | No |
| Session length | About 90 minutes at Karisma | 30 to 45 minutes for a full face, per Sofwave |
| Sessions, per the maker | One, with improvement over time | Most patients need one |
| At Karisma | $1,500 a session, $3,000 for two | Not offered |
Karisma offers only XERF of the two devices.
Why depth matters more than the brand
Sofwave is built around a single target. Its provider FAQ says the heat is localized between 0.5 and 2 mm, centered at 1.5 mm, which is the dermis, the layer where collagen sits. It heats that layer to 60 to 70°C for a few seconds and, by design, stays out of the fat below.
XERF is built around range. Cynosure says its two frequencies and three depth settings reach shallow, middle and deep layers, and that tissue analysis from its studies shows energy reaching the SMAS, a support layer beneath the skin that it links to sagging and jowls. Those depth findings are the maker's own and have not been confirmed by independent human trials.
So the question is less which device wins and more where your looseness lives. Fine lines and crepey texture sit high. Jowls and a soft jawline involve deeper support. A good consultation starts there.
What the FDA paperwork says
Sofwave's April 2025 clearance lists cosmetic effects by name, including wrinkles, a brow lift and a lift under the chin, plus newer lines for acne scars and the upper arms. The same file covers an add-on module, Pure Impact, a muscle stimulator for the abdomen, arms, thighs and buttocks. Sofwave is classed as a focused ultrasound stimulator for aesthetic use.
XERF's August 2025 clearance is narrower in wording. It was cleared as an electrosurgical unit, for electrocoagulation and hemostasis, by comparison with Thermage FLX. Cynosure's own fine print says the words "skin tightening" describe tightening that comes from soft tissue coagulation. That is why this page quotes XERF's clearance in the FDA's own words and nothing more.
Five questions to ask before you choose
- Which layer is my problem in? Surface lines, or deeper sagging along the jaw?
- What evidence is there for my area? Sofwave cites blinded controlled studies with results held up to 12 months. XERF has two small published studies, 39 people and 16 women, both followed for about 3 months and neither controlled.
- How long is the appointment? Sofwave quotes 30 to 45 minutes. A XERF session at Karisma is booked for about 90 minutes.
- Will I need numbing? Sofwave says topical cream can be used. Cynosure says XERF needs none.
- Who oversees the treatment? Ask for the supervising physician's name, whichever device you pick. At Karisma: [TO CONFIRM: medical director name, Jerome]
Questions about XERF vs Sofwave
Is XERF better than Sofwave?
There is no study comparing them. Sofwave has more cleared cosmetic uses and more published follow-up. XERF reaches a wider range of depths, according to its maker, and is newer. Which one fits depends on where your skin is loose and how much evidence you want.
Does Sofwave or XERF cause fat loss?
Sofwave's FAQ says it does not, because it heats only the dermis. Cynosure makes no such statement for XERF, and its 2 MHz setting is described on its blog as suited to deeper heating. Both published XERF studies, 39 people and 16 women, reported only mild, short-lived side effects. See XERF side effects and safety.
Are both safe for darker skin?
Both makers say their device suits all skin types. Those are marketing statements. The larger published XERF study enrolled only skin types I to IV, and its authors call results for types V and VI uncertain. Ask the provider how they set the device for your skin.
Can I get Sofwave at Karisma?
No. Karisma offers XERF, not Sofwave. The XERF consultation is $150 and is credited to your first $1,500 session.
- FDA 510(k) K250146, SofWave System, indications and summary, decision April 18, 2025
- Sofwave for patients, Sofwave Medical, checked October 29, 2026
- Sofwave FAQs for providers, Sofwave Medical, checked October 29, 2026
- FDA 510(k) K251327, XERF, Lutronic Corporation, summary, decision August 11, 2025
- XERF, Structural Skin Tightening, Cynosure Lutronic, checked October 29, 2026
- 1 Month, 100 XERF Patients, provider profile, Cynosure Lutronic blog, December 2, 2025
- Weiss RA et al. Dual-frequency noninvasive monopolar radiofrequency for facial laxity, a prospective multicenter study. Cureus, March 2, 2026
- Erlich, Dahan, Wolf. Retrospective evaluation of XERF. Lasers in Medical Science, August 18, 2026