Home · What Happens During XERF? A Dermatologist Expl
What Happens During XERF? A Dermatologist Explains Dual-Frequency Monopolar RF
Three parts: a medical assessment, a regional treatment plan delivered in staged passes, and simple aftercare. Most of what decides the result happens before the first pulse.
Short answer. XERF is a monopolar radiofrequency treatment that passes energy through the skin to heat the tissue beneath it, using two frequencies — 6.78 and 2 MHz — that heat at different depths. A session begins with a medical check and a face-mapping plan. The dermatologist then delivers staged passes: deeper along the jaw and under the chin, shallower elsewhere. The skin surface is cooled throughout. Most people describe deep, pulsing warmth rather than pain, and return to normal activities the same day.
What XERF is, in one paragraph
XERF is a non-invasive monopolar radiofrequency system made by Cynosure Lutronic. “Monopolar” means energy flows from a treatment tip on the skin to a return pad placed elsewhere on the body, so it can travel deeper than bipolar radiofrequency, where energy runs between two nearby points. XERF combines 2 and 6.78 MHz (FDA 510(k) summary K251327). It holds US FDA 510(k) clearance for “dermatologic and general surgical procedures for electrocoagulation and hemostasis”; skin tightening is the aesthetic use of that controlled heating.
How radiofrequency tightens skin
Heat does two things to collagen. Immediately, it makes existing fibrils contract; microscopy of treated skin shows this straight after treatment (Zelickson 2004). Over weeks and months, the controlled thermal injury prompts new collagen — neocollagenesis — which is documented across radiofrequency devices generally (Austin 2021, O’Connor 2021). That is why XERF has an early effect and a later one; our results timeline explains each stage.
Why two frequencies?
Different frequencies deposit heat differently. In a 2025 study combining computer modelling with minipig tissue, 2 MHz produced broader and deeper heating within the fatty layer, while 6.78 MHz produced more localised heating along the fibrous septa — the connective-tissue strands that run through fat and anchor the skin (Ko 2025). Combining them is intended to heat more than one depth in a single treatment.
What that does and does not mean
That study was laboratory and animal work, and its authors include manufacturer-affiliated researchers. It explains the design rationale. It does not prove a better clinical result than a single-frequency device, and no head-to-head human trial has been published. You may also see claims that XERF “lifts the SMAS”, the deep layer addressed in surgical facelifts. That is a design goal described by the manufacturer, not an established human outcome.
Before treatment: the medical history
This is the most important part of the appointment. dr. Jesslyn asks about implanted electrical devices (pacemakers and defibrillators are an absolute contraindication), pregnancy and metal implants; filler, toxin or skin boosters — what, where and when; previous HIFU, radiofrequency, thread lifts or liposuction in the area; and isotretinoin use, keloid tendency, active skin disease, diabetes and cancer history.
As taught in the advanced programme in Korea, areas with recent injectables or previous energy treatments receive reduced energy, and the thyroid region at the front of the neck is avoided entirely (Seoul training article).
The assessment and plan
Your face is examined sitting upright and at rest. The dermatologist looks at where laxity actually sits, how thick the skin is, and whether fat, bone or muscle is contributing. Standardised photographs are taken. The plan allocates pulses per region and per side, because most faces are asymmetric.
This is also when some patients are told XERF is not their best option. If the main issue is volume loss or a heavy fat pad under the chin, something else comes first.
During the session
- Preparation. Make-up is removed and the skin cleansed. A return pad is placed on the body to complete the monopolar circuit.
- The deeper pass. Lower face, jawline and under-chin first, at the depth intended to reach structural tissue.
- The mid-depth pass. Cheeks and midface.
- Lighter passes where appropriate. The neck at lower energy; forehead or brow only if planned.
- Continuous review. Energy is adjusted to comfort and to how the tissue responds.
How long a session takes depends on the areas treated and on the plan; the clinic confirms the appointment length when you book.
Does XERF hurt?
The manufacturer states that integrated cooling makes treatment comfortable “without the need for numbing” (Cynosure Lutronic, August 2025). That is a device claim.
Most patients describe each pulse as a deep, brief heat followed by cooling. Areas over the jawbone and near nerve pathways feel more intense, and energy is adjusted to feedback throughout. Numbing cream is not usually needed.
The next 48 hours
- Normal: redness and warmth for a few hours; mild swelling for a day or two; tenderness to touch for a few days.
- Uncommon: small raised marks from the tip, fading within days; temporary tingling.
- Rare: blistering, burns or a small area of fat loss, reported with monopolar radiofrequency (Fitzpatrick 2003, Weiss 2006).
You can usually return to normal activities the same day. Use sunscreen daily: without sun protection, patients may develop side effects and not get the results they seek (American Academy of Dermatology). Contact the clinic if you notice blistering, a spreading red area, or pain that is getting worse rather than better.
“Patients often expect the treatment itself to be the complicated part. It is not. The complicated part is deciding where to put the energy and where to hold back. Two people of the same age with the same concern can need quite different plans, because their skin thickness, bone structure and treatment history are different. After more than a hundred XERF treatments I spend more time on the plan than I did at the start, not less.” — dr. Jesslyn Amelia
Who should not have XERF
Not treated: anyone with a pacemaker, an implantable defibrillator or another implanted electrical device — monopolar radiofrequency passes current through tissue and can interfere with them. Pregnancy.
Assessed carefully first: metal implants or permanent filler in the treatment area; active skin infection or inflammatory skin disease at the site; a history of keloid scarring; isotretinoin within the past six months; current or recent malignancy; poorly controlled diabetes.
Probably better served by something else: heavy skin excess, where a surgical result is more meaningful than a tightening treatment. The full list sits on the XERF safety section.
Want to know how your own session would be planned?
Send a photo and your treatment history, and dr. Jesslyn will explain what she would plan and why.
Ask dr. Jesslyn on WhatsAppTreatment details and results: XERF at Elea Clinic
Sources
- FDA 510(k) summary K251327 — frequencies, indication and predicate.
- Ko 2025 — modelling and minipig histology of 6.78 and 2 MHz heating.
- Zelickson 2004; Austin 2021; O’Connor 2021 — mechanism and time course.
- Fitzpatrick 2003; Weiss 2006 — complication rates with monopolar RF.
- Cynosure Lutronic, August 2025 — manufacturer statements on cooling and numbing.
- American Academy of Dermatology — sun protection alongside treatment.
Questions we are asked
How long does a XERF session take?
It depends on the areas treated and on your plan; the number of pulses is set at consultation rather than from a menu, and the clinic confirms the appointment length when you book.
Is XERF the same as Thermage?
Both are monopolar radiofrequency, and the FDA cleared XERF as substantially equivalent to the Thermage FLX. XERF uses two frequencies; the Thermage FLX works at 6.78 MHz. See XERF vs Thermage.
Can I go back to work the same day?
Most people can. Some prefer to avoid an important event for a day or two in case of swelling.
Can I have XERF if I have filler?
Often yes, with energy reduced over filled areas, but timing matters. Tell the dermatologist what was injected, where and when — see combining XERF with skin boosters.
Does XERF need numbing cream?
The manufacturer states that the device’s cooling is designed to avoid numbing. In practice most patients are treated without it, and energy is adjusted to comfort.
Medically reviewed by dr. Jesslyn Amelia, Sp.D.V.E — Dokter Spesialis Dermatologi, Venereologi dan Estetika. Registered with the Indonesian Ministry of Health, STR JT00000382760637. Verify registration. Last reviewed 23 September 2026. Individual results vary; this page is general information and not a substitute for consultation.