![Official] Smart Skin Clinic｜Aesthetic Dermatology Group (Jimbocho, Yokohama)](https://smartskin-clinic.com/wp-content/uploads/2023/05/Smart-skin-clinic-ロゴ500-×-100-px.png)
XERF for Sagging Skin Treatment
"How is XERF different from other sagging treatments?"
"I'm starting to worry about sagging along my jawline, but the idea of surgery is intimidating..."
"I've tried HIFU before, but the pain was too intense to continue."
"I want to improve my nasolabial folds and marionette lines, but I can't afford any downtime."
Do any of these concerns about sagging treatments sound familiar?
Hello, this is Smart Skin Clinic, an aesthetic dermatology clinic.
In this article, we take a detailed, medically grounded look at XERF, a radiofrequency device drawing attention for sagging treatment — how it works, the effects you can expect, how it differs from other treatments, what the procedure involves, and what downtime to expect.
*If there's something specific you'd like to know, you can jump straight to it using the table of contents below.
Group Chief Director, Smart Skin Clinic Group
Ishii Kota
Career
Graduated from Juntendo University School of Medicine
Worked at Tokyo Women's Medical University Hospital and affiliated facilities
Worked at a major aesthetic clinic in Tokyo
Affiliations / Qualifications
Board-certified specialist, Japan Surgical Society
Board-certified specialist, Japanese Society of Anti-Aging Medicine
What Is XERF?
XERF is a monopolar RF (radiofrequency) therapy device developed by the South Korean company LUTRONIC.
It received certification in 2024 from Korea's MFDS (Ministry of Food and Drug Safety), the Korean equivalent of Japan's Ministry of Health, Labour and Welfare.
The characteristics of Zarf are:deliver thermal energy "three-dimensionally," from the dermis down through the subcutaneous fat layer.
As a result,Addresses multiple skin concerns simultaneously, including double chins, sagging jawlines, nasolabial folds, and marionette lines, as well as improving skin firmness, radiance, and pore tighteningcan be expected.
Who XERF Is Recommended For
- Those who want to address both sagging and skin quality without surgery
- Those who are sensitive to pain
- Those who cannot afford downtime
- Those in their 30s to 50s who are starting to notice sagging
- Those who want to avoid the risk of cheek hollowing
- Those concerned about jowls beside the mouth, jawline laxity, or a double chin
- Those seeking natural-looking rejuvenation
Three Key Features of XERF
- Monopolar RF (radiofrequency)
- A dual frequency of 6.78MHz + 2MHz
- Three irradiation modes tailored to depth
①Monopolar RF and the Mechanism Behind Sagging Improvement
Radiofrequency (RF) generates heat by causing water molecules in the skin tissue to vibrate.
The mechanism by which this heat improves sagging is as follows:
- Immediate effect: The heat causes collagen fibers to contract, so you can expect to feel your skin tighten immediately after the treatment. This technique takes advantage of the property of proteins to denature when heated (the same principle that causes grilled meat to shrink).
- Long-term effect: As part of the wound-healing response triggered by thermal stimulation, fibroblasts are activated and new collagen and elastin are produced. This effect peaks over the 1 to 3 months following treatment, leading to lasting improvements in skin firmness and elasticity.
RF treatments are also categorized as "monopolar," "bipolar," or "multipolar" depending on the number of electrodes used, and XERF employs monopolar RF.
Monopolar RF is a method that passes high-frequency current between an “electrode applied to the treatment area” and an “electrode attached to the body (counter electrode),” forming a closed circuit within the body to heat the target area. Because the energy reaches a wide area, it is suitable for mild to moderate sagging.
[Types and Characteristics of RF]
| RF type | Monopolar RF | Bipolar RF | Multipolar RF | Microneedle RF |
| Frequency | 6.78MHz / 2MHz | 1 MHz | 1 MHz | 2 MHz |
| Benefits | Heat penetrates broadly and deeply | Treatment depth can be specified | Energy concentrates centrally | Treatment depth can be specified |
| Drawbacks | Treatment depth cannot be specified | Treatment depth is shallow | Treatment depth cannot be specified | Downtime occurs due to skin puncture |
| Effect | Tightening · Promoting Skin Regeneration | Contour correction | Contour correction | Promotes skin regeneration |
2. A World First: What Is the "Dual Frequency" of 6.78MHz + 2MHz?
The second feature of ZAH is the world’s first technology capable of simultaneously emitting two different frequencies—“6.78 MHz” and “2 MHz”—.
Conventional RF devices (such as Thermage and Volnewmer) typically use a single 6.78MHz frequency.
Why combine two frequencies? The answer lies in controlling treatment depth.
[The Relationship Between Frequency and Depth]
- 6.78MHz: acts efficiently on the dermis through the superficial fat layer
- 2MHz: reaches the deeper fat layer
By combining these two , thermal energy can be delivered in a "three-dimensional" manner from the superficial layers to the deeper layers.
As a result, it has become possible to simultaneously treat “deep sagging” and “skin texture improvement”—which were difficult to address with conventional RF treatments.
In a preclinical study comparing 6.78MHz and 2MHz radiofrequency (i.e., XERF) in pigs, 2MHz was found to warm deeper tissue more readily, while 6.78MHz acted more effectively along the skin's fibrous structure. Combining the two produced more pronounced changes in components such as the collagen fibers that support skin firmness, with no fat cell damage observed. (Preclinical study)
3. Three Irradiation Modes and the "Three-Layer" Concept
The third feature of Zarf is that it offers three different irradiation modes depending on the depth of the skin.
This enables "customized irradiation" tailored to each individual's skeletal structure, fat distribution, and type of sagging.
| Mode | Deep | Middle | Shallow |
| Frequency | 6.78MHz + 2MHz (dual frequency) | 6.78MHz | 6.78MHz |
| Target | Deep fat layer | Deep dermis to superficial fat layer | Superficial dermis |
| Effect | Fat Cell Volume Reduction Lifting Effect from Deep Within | Promotes the regeneration of collagen and elastin in the dermis for a natural lifting effect | Immediate improvement in skin quality |
| Indications | Double chin Severe sagging along the jawline Loose skin around the mouth | Nasolabial folds Marionette lines Gorgo lines Mild to moderate sagging | Fine lines Lack of firmness and radiance Enlarged pores Facial redness |
What Effects Can You Expect From XERF?
By combining the characteristics of monopolar RF with its three irradiation modes, XERF delivers a range of aesthetic benefits.
[Expected Effects]
- Jawline tightening, a slimmer-looking face, and V-line definition
- Reduced jowls beside the mouth and double-chin fat
- Improvement of nasolabial folds, marionette lines, and Golgo lines
- Improved skin firmness, radiance, and texture
- Long-term rejuvenating effects through increased collagen and elastin production
- Tighter pores and improved facial redness
Jawline tightening, a slimmer-looking face, and V-line definition
A loose, sagging jawline makes the face look larger and can add years to your appearance.
The Deep mode's three-dimensional approach to the deep fat layer can be expected to tighten a jawline blurred by aging, define the V-line, and create a slimmer-looking face.
You may notice a change in your facial contours immediately after the procedure.
Reduced jowls beside the mouth and double-chin fat
Jowls beside the mouth and a double chin are mainly caused by fat accumulation. This is especially common from the late 30s onward, when a slower metabolism makes fat more likely to build up under the chin.
By delivering concentrated heat to the deep fat layer using Deep Mode, this treatment can be expected to address mild to moderate concerns under the chin and around the mouth without the use of a scalpel.
Improvement of nasolabial folds, marionette lines, and Golgo lines
Nasolabial folds and marionette lines tend to form in areas prone to sagging, involving not only the dermis but also the subcutaneous tissue and the ligaments that anchor the skin to it.
Applying thermal stimulation to the deep dermis promotes medium-to-long-term collagen remodeling, which can be expected to improve skin elasticity and reduce wrinkles and sagging.
Improved Skin Firmness, Radiance, and Texture | Skin Quality Benefits (Shallow Mode)
What sets ZAHF apart from other high-frequency treatments is that it can improve skin texture at the same time as treating sagging skin.
Promoting collagen production in the superficial dermis supports skin turnover and circulation, leading to improved firmness, radiance, and texture.
Immediately after the treatment, you can expect to notice changes such as "my skin feels tighter" and "my makeup goes on better."
Long-term rejuvenating effects through increased collagen and elastin production
What sets Zarf apart is,not only an "immediate effect right after treatment" but also a "medium-to-long-term effect from collagen regeneration over the following 1 to 3 months".
Regular maintenance can help offset the loss of collagen associated with aging.
Tighter pores and improved facial redness
RF treatmentTightens pores by stimulating collagen production around themcan be expected.
In addition, the capillaries that have dilated due to thermal stimulation will constrict, which may help improve facial redness .
XERF Downtime, Side Effects, and Risks
XERF is a treatment with minimal downtime, though depending on individual factors and the specifics of treatment, the following reactions may occur.
[General Downtime Guidelines]
- Redness: a few hours to about half a day after treatment
- Warmth: a few hours
- Mild swelling: may last until the next day (usually barely noticeable)
These are temporary reactions that resolve naturally, andIn most cases, you can return to your normal daily activities on the day of the procedure..
Post-XERF Care | Everyday Precautions
How you care for your skin after treatment affects how long the results last and the risk of side effects.
Please keep the following in mind.
- Cleansing and makeup: possible immediately after treatment. Please be gentle and avoid friction.
- Bathing, saunas, and intense exercise: increased blood flow on the day of treatment may prolong redness, so we recommend avoiding long baths, saunas, and intense exercise, and sticking to a shower instead.
- Moisturizing and sun protection: skin tends to hold heat and dry out more easily after treatment. Be sure to moisturize thoroughly and apply sunscreen to protect against UV exposure.
How Much Does XERF Hurt? Is Anesthesia Required?
Some people may think, “I’m concerned about sagging, but RF treatments are painful.”
It’s true that traditional Thermage treatments could be quite painful.
However, the pain from a Zarf is often described as “feeling like taking a warm shower”, and in most cases, anesthesia is not necessary.
Wave Fit Pulse: Reducing Pain
Zarf uses a patented technology called “Wave Fit Pulse” to help reduce painso it does.
Wave Fit Pulse delivers energy intermittently as "waveform pulses."
Specifically, by finely alternating between high and low output during treatment, itA design that achieves all three of the following: “delivering heat deep into the skin,” “minimizing damage to the epidermis,” and “reducing pain,” andso it does.
A Powerful Cooling System
XERF's handpiece is also equipped witha powerful cooling systemis being provided.
During treatment,By cooling the skin's surface while delivering the light, we aim to "reduce the risk of burns," "minimize pain," and "provide a comfortable treatment experience."so it does.
Thanks to the Wave Fit Pulse and the cooling system, it is designed to minimize severe pain.
Who Should Not Receive XERF | Contraindications
- Those with a pacemaker or metal implants (as radiofrequency energy may affect these devices)
- Those who are pregnant or breastfeeding (as safety has not been established)
- Those with a tendency toward keloid scarring, diabetes, or other conditions affecting wound healing
- Those with metal plates, silicone, gold threads, or other implants in the treatment area
- Those with significant skin inflammation or infection
When Can You Expect Results From XERF? How Long Do They Last? Are Results Visible After One Session?
| Immediate effect | Right after treatment to 2 weeks | Thanks to the immediate contraction of collagen fibers, You can expect to feel a tightening effect immediately after the treatment. |
| Medium-to-long-term effect | 1 to 3 months later | Thanks to collagen regeneration, the effects peak 1 to 3 months later. |
| Duration of effect | 6 months to 1 year | – |
| Interval between sessions | Every 3 to 6 months | – |
XERF's effects appear in two stages: an "immediate effect" and a "medium-to-long-term effect."
While some people notice a difference after just one session, we recommend regular maintenance to sustain the results.
Results vary from person to person.
How XERF Differs From HIFU and Other RF Treatments
Many people wonder, "Should I choose XERF or HIFU?" or "How is it different from Volnewmer or Thermage?"
Here, we take a closer look at how XERF compares with other major sagging treatments.
| Device | XERF | HIFU | Thermage | Volnewmer | Potenza |
| Energy / type | Monopolar RF (6.78MHz + 2MHz) | Ultrasound | Monopolar RF (6.78MHz) | Monopolar RF (6.78MHz) | Needle RF |
| Target | Dermis to Subcutaneous Fat ( surface heating) | SMAS layer (point heating) | Dermis to subcutaneous tissue | Dermis to superficial fat layer | Dermis |
| Main effects | Toning Fat Reduction Skin Texture Improvement | Lift-Up Firming | Tightening | Firming Skin Elasticity | Acne scars, pores, and skin quality improvement Improvement of sagging and fine lines |
| Pain | Minimal | Pain that resonates in the bone | Strong | Minimal | Pain as if being pricked by needles repeatedly A tingling sensation like an electric shock |
| Downtime | Almost none | A few days ・Redness ・Swelling ・Pain similar to muscle soreness | Almost none | Almost none | A few days to about a week ・Redness ・Swelling ・Bruising |
①Differences from HIFU *Not offered at our clinic
XERF is recommended for those with more fat who also want to improve skin quality, while HIFU is recommended for those who want a strong lift from the fascia.
- HIFU: Lifts by heating the SMAS layer at individual "points."It is suitable for a "lift," but a loss of volume in the cheeks may occur,a risk of cheek hollowing.
- XERF: Tightens by heating the fat layer through the dermis across a broad "surface."It is suitable for “skin tightening” and “fat reduction,” andIt is generally considered that changes in cheek volume can be easily adjusted through the treatment plan.
② Differences from Thermacool Volnuma
Although the Bolneuma is also a widely used device,because XERF also uses a 2MHz wavelength, it can reach a deeper layer (the subcutaneous fat layer).
While retaining the feature of “low-pain RF,” Zarf is designed to meet the need for “tightening fat layers that are a little deeper.”
- Thermage: A pioneer in RF sagging treatment, butIt can be painful, and the price range is on the higher side.
- Borneuma: It's a good device that causes little pain, but it operates at a single frequency.
- XERF: Building on Volnewmer'slow pain profile, XERF adds a dual frequency that can reach a deeper fat layerThis is a key feature. It can be described as similar to “low-pain RF.”
Looking briefly at the history of RF (radiofrequency) treatment helps clarify these differences.
- Thermage (The Gold Standard, But Painful)
For a long time, “Thermage” was considered the gold standard in RF treatment. While it provides powerful skin tightening at a frequency of 6.78 MHz, it had the drawbacks of “sometimes being painful” and “being on the higher end of the price range.” - Borneuma (Promoting Low-Pain RF)
After Thermage's patent expired, devices such as Volnewmer emerged. Using the same 6.78MHz frequency as Thermage, they improved on its cooling performance to allow for a more comfortable treatment with less pain. - 3rd Generation: Zarf (Evolution to Dual Frequencies)
And the latest Zarf model has brought about a technological innovation that goes beyond simply reducing pain, adding “2 MHz” to the 6.78 MHz frequency.
3. Differences From Potenza (Needle RF) *Not offered at our clinic
- Want to treat acne scars or uneven skin texture and can tolerate downtime? → Potenza
- Want to address overall facial sagging and fat but can't tolerate downtime? → XERF
Potenza is well known as a "microneedle RF" device that inserts ultra-fine needles into the skin, like a shiatsu press, and delivers RF energy from the needle tips.
It uses frequencies of around 1 to 2MHz, but its approach differs fundamentally from XERF.
- Potenza (with needles): This treatment involves physically piercing the skin with needles to deliver heat. It is suitable for treating “skin surface irregularities,” such as acne scars and deep pores, but it does involve some downtime, including bruising and redness.
- XERF (without needles): Delivers heat to deeper layers using a longer 2MHz wavelength, without piercing the skin. Because the skin's surface isn't damaged, it can tighten the fat layer with no downtime.
The Synergy Between XERF and Skin Boosters (Same-Day Treatment Available)
You can receive both “Sagging and Tightening Treatment” using ZAF and “Skin Texture Improvement” using various skin boosters on the same day .
Since each treatment targets different layers of the skin and uses a different approach, their effects do not cancel each other out. By completing the entire process in a single day, we can reduce the burden of multiple clinic visits.
Treatment Order Must Always Be "XERF First, Then Skin Booster"
The most important thing to remember when performing both procedures on the same day is to always “perform the ZAF first, followed by the skin booster injection”. There is a medical basis for this.
1. To Avoid the Risk of Heat-Denaturing the Formulation
Ingredients in skin boosters (such as non-cross-linked hyaluronic acid or polynucleotides) can potentially break down or lose structure when exposed to high heat. If the injection were performed first, XERF's powerful RF heat could damage these valuable active ingredients.
2. To Take Advantage of the "More Receptive" Skin Environment After RF Treatment
XERF's thermal action boosts blood flow in the dermis, temporarily increasing cellular metabolic activity. Injecting a skin booster into skin in this "activated, more receptive" state can help active ingredients reach the tissue more efficiently.
Three Expected Synergistic Effects
Combining XERF with a skin booster is not simply additive — it multiplies "heat-based tightening" with "formulation-based skin regeneration support."
1. A Three-Dimensional Approach: "Foundational Tightening" Plus "Surface Skin Quality Improvement"
Zarf’s multi-frequency monopolar RF delivers heat over a wide area from the dermis to the fat layer, powerfully tightening the “deep-layer laxity” that causes sagging. Meanwhile, the Skin Booster directly targets the area just beneath the epidermis through to the dermis, improving hydration, firmness, and fine lines. To use a building analogy, Zarf “reinforces the framework (laying the foundation),” while the Skin Booster simultaneously “renovates the wallpaper (improving texture)” .
2. A "Double Approach" to Collagen Production
XERF's thermal stimulation triggers the skin's wound-healing response, switching on collagen and elastin production. Injecting a skin booster on top of this delivers the "materials" (such as amino acids and hyaluronic acid) and "stimulation" needed for cellular remodeling directly to the tissue, accelerating the strengthening of the skin's foundation more efficiently.
③ Reconstruction of the Extracellular Matrix (ECM)
To make the tightening effect last and maintain beautiful skin, it's important for the dermis's extracellular matrix — the environment that supports collagen and other structural components — to be in good condition. Applying a hyaluronic acid- or PN-based skin booster to skin that has just received XERF's heat reinforces proper hydration retention and a regenerative environment, guiding the skin toward a more three-dimensional, healthy state.
About the Combination of Zarf and Skin Booster
Even among skin boosters, each formulation has its own strengths and the specific changes it brings. Likewise, the results of XERF's RF treatment vary significantly depending on how much heat is delivered and at what depth.
Since its opening, Smart Skin Clinic has offered a variety of skin booster formulations, including Jubelook, Profhilo, Snekos, and Rejuran.
With the introduction of the next-generation high-frequency RF technology “XERF,” we can now combine “injections tailored to the characteristics of the formulation” with “irradiation protocols for skin tightening devices.”
After the doctor examines your bone structure, skin thickness, and degree of sagging, they will explain the combination of Zarf’s treatment depth and the skin booster formulation.
Smart Skin Clinic Pricing
*All prices include tax.
*Please note that our clinic provides private medical care, and insurance does not apply.
* The 400-shot and 600-shot options take longer, so there is a last-appointment cutoff time.
Jimbocho Clinic: until 19:00 on weekdays / until 18:00 on weekends and holidays | Yokohama Clinic: until 18:00 every day
If you book after the above times, the treatment cannot be completed within business hours, so we may ask you to reschedule.
The 200-shot and 300-shot options are not subject to the above restrictions.
FAQ
- Worried that XERF might cause cheek hollowing?
-
The risk of sunken cheeks is considered low, and since the heat is expected to reposition sagging fat, an improvement in cheek volume is also anticipated.
In the past, the general approach was to “avoid treating areas with skin sagging,” but recent evidence has shown that treating these areas without avoiding them is effective. At Smart Skin Clinic, we have incorporated these latest findings and now perform treatments with the goal of improving skin sagging. - Does XERF show results after just one session? What is the ideal treatment frequency?
-
Some patients notice a change after just one session, but since XERF cannot stop new age-related changes from occurring, we recommend maintenance treatments roughly every 3 to 6 months to sustain the results. Individual results vary.
- Is XERF treatment painful? Is anesthesia required?
-
This treatment is performed without anesthesia.
Thanks to Wave Fit Pulse technology, discomfort is greatly reduced. The sensation is similar to a warm shower. - Can I apply makeup right after XERF treatment?
-
Yes, you can apply makeup immediately after the treatment.
Treatment Flow
You can easily book from your smartphone.
A smart, effortless check-in: just give your name and our clinic IT system completes reception right away.
During your consultation, please feel free to ask us about anything that concerns you. After listening to your concerns, we will explain the details of the treatment.
After the electrode pads are attached, gel is applied to the treatment area and energy is delivered while checking in with you throughout. The output is adjusted according to your skin condition and pain tolerance. You will typically feel a gentle warming sensation during treatment, with little to no significant pain.
We will provide detailed explanations regarding aftercare for the treated area and precautions to take in your daily life. We also explain home care routines—including oral medications and skincare products that can help alleviate your concerns—from the perspective of prevention and maintenance.
Details
| Treatment Time | Treatment time varies depending on the number of shots. 200 shots: approx. 45 minutes 300 shots: approx. 60 minutes 400 shots: approx. 75 minutes 600 shots: approx. 105 minutes *The above are estimates only. Actual time may vary depending on the situation. |
| Recommended Number & Frequency of Treatments | We recommend treatment at intervals of roughly 3 to 6 months. |
| Downtime | Little to none · mild redness or swelling |
| Treatment on the day of counseling | Available |
| Makeup | Possible immediately after treatment |
| Skincare | Possible right after the treatment |
| Shower | Normal activities possible the same day; bathing possible from the next day (avoid long baths on the day of treatment) |
| Pain | A sensation similar to standing under a warm shower |
*Results vary from person to person.
[Legal Notices]
XERF treatment involves the use of medications or medical devices not approved in Japan. These medications and devices are imported personally under the judgment of our clinic's physicians, in accordance with the required personal import procedures.
Please refer to this page for information on medications and similar items that require caution in personal importation.
Ministry of Health, Labour and Welfare, "Medications and Similar Items That Require Caution in Personal Importation."
XERF Treatment at Smart Skin Clinic
XERF is a treatment for sagging skin that prioritizes a balance between “pain,” “downtime,” and “results.”
If you'd like a treatment you can relax through without enduring pain, want to address fat around the mouth and chin at the same time, and also want firmer, more radiant skin —
we warmly invite you to book a free consultation.
After your examination, we will explain the details of your treatment.
Physician Who Supervised This Page
Smart Skin Clinic, Chief Medical Director / Physician
Kota Ishii
We oversee treatment policies across the entire group, tailored to the skin condition of each individual patient. The content on this page has been reviewed and approved in line with our clinic's treatment policies.
Interview with Director Kota Ishii
Kota Ishii, our Chief Medical Director, shares our clinic's approach to patient care.
Reference
Clinic List
Jimbocho Clinic
〒101-0054
3-16-1 Kanda Nishiki-cho, Chiyoda-ku, Tokyo, EX Kanda Nishiki-cho Building 8F (general reception) / 7F
Hours: Mon–Fri 11:00–20:00 / Sat & Sun 10:00–19:00
Yokohama Clinic
〒221-0835
TS Plaza Building 2F, 2-23-2 Tsuruya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa
Hours: 10:00–19:00
Hatchobori Clinic
104-0032
2nd Floor, Tokyo NS Building, 2-29-4 Hatchobori, Chuo-ku, Tokyo
Hours: 10:00 a.m.–7:00 p.m. (Closed from 1:00 p.m. to 2:00 p.m.) / Closed: Mondays and Thursdays
About the physician supervision of this site
This site is operated under the supervision of a Smart Skin Clinic supervising physician.
This page was produced in accordance with the Medical Advertising Guidelines Medical Advertising Guidelines revised and enforced in June 2018, under which we produce and provide this information.
- Scope of supervision: treatment descriptions, risks and side effects, price display
- Last Reviewed: August 1, 2026