XERF vs. Thermage: The New Korean RF Treatment Explained

Until 2024, if you wanted non-invasive radiofrequency skin tightening, your choices were essentially Thermage or one of its imitators. Thermage had been the dominant monopolar RF device for nearly two decades, used by dermatologists worldwide as the standard for tightening sagging skin without surgery.

Then XERF launched in Korea, and within 18 months it had displaced Thermage as the preferred RF device in most major Cheongdam dermatology clinics. Now it's hitting the US market — Kim Kardashian called it her new favorite tightening treatment, top NYC and LA dermatologists are stocking it in their practices, and Americans are starting to fly to Seoul specifically for it.

This guide compares the two devices honestly: how each works, what each does well, where each falls short, and how to decide between them. We've watched both treatments performed in Seoul clinics dozens of times. Here's what we've learned.

Quick Summary

If you only have 60 seconds:

• Thermage is the original and best-validated monopolar RF device. Single-frequency (6.78 MHz). One session per year. Established protocols. Usually requires numbing cream. Established US pricing ($2,000–$4,000 per session).
• XERF is the Korean-developed next generation. Dual-frequency (6.78 MHz + 2 MHz). Two sessions 4–6 weeks apart. Reaches deeper into the SMAS layer. Better cooling means usually no numbing. Lower Seoul pricing ($800–$1,800 per session).
• Choose Thermage if you want a single annual treatment with the most established track record, and you tolerate discomfort well.
• Choose XERF if you want a more comfortable experience, are willing to do two sessions, want deeper structural lifting (jowls, jawline), or are price-sensitive and considering a Seoul trip.

How Each Treatment Works

Both XERF and Thermage are monopolar radiofrequency devices. They work the same way at a fundamental level: radiofrequency energy is delivered to the skin, which heats the dermis to 55–65°C. This heat causes existing collagen fibers to contract immediately (the source of immediate tightening) and damages them just enough to trigger fibroblasts to produce new collagen and elastin over the following 2–6 months (the source of long-term improvement).

The differences come down to how each device delivers that energy.

Thermage FLX

Thermage uses a single 6.78 MHz frequency. This frequency reaches the dermis effectively but doesn't penetrate as deeply as some newer devices. The current FLX generation features the AccuREP system that adapts energy delivery to each pulse, and it includes cooling bursts to protect the skin surface.

Treatment areas are divided into a grid using a temporary pattern drawn on the skin. The technician moves systematically through the grid, delivering pulses across the entire treatment area. A typical full-face treatment takes 60–90 minutes. Most patients find it uncomfortable enough that numbing cream or oral pain medication is recommended, especially on bony areas like the forehead and jawline.

XERF

XERF combines two frequencies — 6.78 MHz and 2 MHz — in a single device. The 6.78 MHz frequency targets the dermis (similar to Thermage), while the 2 MHz frequency penetrates deeper, reaching the SMAS (Superficial Musculoaponeurotic System). The SMAS is the same fibrous tissue layer that surgeons tighten during a facelift. By heating this layer non-invasively, XERF creates structural lifting effects that single-frequency devices can't match.

The device offers three depth settings (shallow for thin areas like the forehead, middle for cheeks and neck, deep for the lower face and jowls) and ten intensity levels. Real-time impedance feedback adjusts energy delivery based on your specific skin properties. Up to 12 cooling bursts per shot keep the skin surface comfortable while the deeper tissue heats. This advanced cooling is the main reason most patients tolerate XERF without numbing cream.

What Each Treatment Does Best

Thermage strengths

• Surface tightening and texture refinement. Particularly effective for crepey skin on the neck, around the eyes, and on the body (arms, abdomen, thighs).
• Long single-session treatment. One treatment per year is the standard protocol. Convenient if you don't want to schedule multiple visits.
• Well-validated for body treatments. Decades of data on body applications, particularly abdomen, thighs, and arms.
• Predictable results across providers. Because the protocol is standardized and well-known, results from a competent provider are reasonably consistent.

XERF strengths

• Lower face lifting and jawline definition. The dual-frequency reach to the SMAS layer is genuinely meaningful here. This is where XERF visibly outperforms single-frequency devices.
• Comfort. Most patients describe XERF as warm but not painful. Many providers don't use numbing cream at all. This isn't marketing — it's a real difference.
• Faster treatments. The larger 6 cm² treatment tip (vs. Thermage's 4 cm²) and quicker pulse delivery mean a full face treatment often takes 45–60 minutes instead of 90.
• Customization. Three depth settings let providers target specific areas with different intensities — heavier work on jowls and jawline, gentler work on the forehead.

Cost Comparison: Seoul vs. US

This is where the choice gets interesting if you're already considering a Korea trip.

Thermage FLX pricing

• Seoul: $500–$1,500 for full face and neck
• NYC/LA: $2,500–$4,500
• Mid-tier US cities: $1,800–$3,500

XERF pricing

• Seoul: $800–$1,800 for full face and neck (per session, recommended 2 sessions)
• NYC/LA: $1,500–$3,000 per session
• Mid-tier US cities: $1,200–$2,500 per session

The honest math

For a single Thermage treatment, the savings flying to Seoul might be $1,000–$2,000 — significant but probably not enough to justify a trip on its own.

For XERF (which requires 2 sessions for optimal results), the gap is more meaningful. Two XERF sessions in NYC could cost $4,000–$6,000. Two sessions in Seoul cost $1,600–$3,600 — a savings of $2,000–$3,000 that approaches the cost of a Seoul trip.

The real value isn't usually a single treatment — it's bundling. People going to Seoul for XERF often combine it with Rejuran (3 sessions), Juvelook, laser toning, or other treatments. The cumulative savings on a 7–10 day trip can easily exceed $5,000.

For a complete cost analysis of Seoul treatment trips, see our Korean skincare trip cost guide.

Comfort and Treatment Experience

If pain tolerance is a factor in your decision, this section matters.

Thermage experience

Thermage is genuinely uncomfortable. Each pulse delivers a sharp heat sensation that intensifies on bony areas (forehead, jawline, around the eyes). Most providers prescribe oral pain medication and apply topical numbing cream 30–45 minutes before treatment. Many patients describe Thermage as a 6–7 out of 10 on the pain scale.

The cooling bursts help, but they don't eliminate the discomfort — they just keep the surface from burning while the deep tissue heats. For 60–90 minutes, you're getting hundreds of these pulses across your face. It's tolerable but not pleasant.

XERF experience

XERF is substantially more comfortable. The combination of larger cooling bursts (up to 12 per pulse vs. Thermage's smaller cooling), real-time impedance feedback that adjusts energy delivery, and the dual-frequency approach that distributes heat differently means most patients describe XERF as "warm but tolerable" — typically a 3–4 out of 10 on the pain scale.

Many Korean providers don't use numbing cream at all. Some US providers still apply numbing cream out of caution, but most patients report it isn't necessary. For pain-sensitive patients, this is a genuine quality-of-life advantage.

Results and Longevity

What to expect from Thermage

Immediate effects are minimal — most of the visible improvement comes from collagen remodeling over 2–6 months. Peak results typically appear at 3–4 months post-treatment. Results last approximately 12–24 months for most patients, though this varies significantly with age, skin condition, and lifestyle factors (sun exposure, smoking, weight changes).

Thermage is best understood as a maintenance treatment. Most providers recommend annual treatments to maintain results.

What to expect from XERF

Immediate effects are more visible than with Thermage — patients often see noticeable lifting within 24 hours due to collagen contraction. Continued improvement happens over 2–6 months as new collagen forms. Peak results typically appear at 3 months post-second-session.

Because XERF's protocol involves two sessions 4–6 weeks apart, the building effect is more pronounced. Results typically last 12+ months. Many providers recommend a single booster session at 6–12 months to extend the timeline.

Honest results expectations

Neither treatment delivers facelift-level results. Both produce subtle to moderate improvement — sharper jawline, less visible jowling, smoother neck, more lifted overall facial contour. If you have moderate-to-severe skin laxity, neither device alone will be enough — you'll likely need surgery or a combination of treatments (XERF or Thermage + Ulthera + thread lifts + filler).

For mild-to-moderate laxity, both deliver meaningful results. XERF tends to outperform Thermage on lower face lifting specifically. Thermage tends to outperform XERF on neck and body treatments.

Who Should Choose What

Choose Thermage if:

• You want a single annual treatment (vs. two sessions 4–6 weeks apart)
• You're focused on body areas (arms, abdomen, thighs)
• You tolerate discomfort well
• You want the most established, longest-validated technology
• You're treating crepey skin or texture more than structural lifting

Choose XERF if:

• Your primary concern is jowls, jawline, or lower-face laxity
• Pain tolerance is a real factor for you
• You can commit to two sessions in 6 weeks
• You're traveling to Seoul anyway and want lower per-session pricing
• You want the latest technology (XERF is from 2024, vs. Thermage's late 2000s baseline)
• You have mild-to-moderate laxity and want the most lifting effect possible non-invasively

Combining With Other Treatments

Korean dermatologists often combine RF tightening with other modalities for layered results. Common protocols:

• XERF + Rejuran: XERF for structural lifting, Rejuran for surface skin quality. Schedule Rejuran 2 weeks before or 4 weeks after XERF.
• XERF + Ulthera: Ulthera reaches even deeper than XERF (focused ultrasound vs. RF). Together they create more comprehensive lifting. Most clinics space these 4–6 weeks apart.
• Thermage + Ulthera: The traditional combination. Ulthera for structural lift, Thermage for surface tightening. Standard protocol for non-surgical full-face rejuvenation.
• XERF + filler: XERF tightens; filler restores volume. Done in the right order (XERF first, filler 2–4 weeks later), this can produce surprisingly natural-looking results.

For a complete overview of how Korean dermatologists structure these combinations, see our complete Korean treatments guide.

Finding the Right Clinic in Seoul

If you're considering XERF in Seoul, three criteria matter:

1. Lutronic-certified provider. XERF is a Lutronic device. Clinics with proper Lutronic training and certification follow validated protocols. Ask the clinic if their dermatologists are Lutronic-trained on XERF specifically.

2. Experience with the device. Korean clinics have had XERF longer than US clinics. Look for clinics that have been using it since 2024 and have performed at least 100 treatments. Newer clinics adopting XERF in 2026 have less refined protocols.

3. Realistic consultation. Good clinics will tell you honestly if XERF isn't right for your skin laxity. If they recommend it for severe sagging that really needs surgery, that's a red flag. Quality Cheongdam clinics will recommend the right treatment for your situation, even if it's not the most expensive option.

For our framework on evaluating Seoul clinics, see how we vet clinics and factory clinics vs. specialist clinics.

Aftercare for XERF and Thermage

Both treatments have minimal aftercare requirements compared to laser or microneedling. Standard recommendations:

• First 24 hours: Avoid heat (sauna, hot showers, intense exercise). Mild redness is normal and resolves within hours.
• Days 1–7: Resume normal skincare including actives. Apply mineral SPF 50+ daily. Avoid aggressive exfoliation.
• Weeks 2–8: Topical PDRN and peptide skincare can support the collagen remodeling process initiated by the RF treatment. See our PDRN protocol for the routine that pairs well with RF treatments.
• Long-term: Daily mineral SPF prevents UV damage from breaking down the new collagen you're building. Skipping sunscreen significantly reduces treatment longevity.

For complete post-procedure routines, see our post-treatment recovery protocol.

Frequently Asked Questions

Is XERF FDA-cleared in the US?
Yes. XERF received FDA clearance for skin tightening in 2024 and is now available at growing numbers of US dermatology practices, particularly in NYC and LA.

How many XERF sessions do I need?
Most providers recommend 2 sessions spaced 4–6 weeks apart for optimal results. A single booster session at 6–12 months can extend results.

How long until I see XERF results?
Some immediate tightening from collagen contraction, visible within 24 hours. Continued improvement over 2–6 months as new collagen forms. Peak results typically appear at 3 months after the second session.

Can I get XERF if I have fillers or Botox?
Yes, but timing matters. Most providers wait at least 2 weeks after Botox or filler before XERF, and at least 2 weeks after XERF before adding new injectables. Discuss with your provider.

Is XERF safe for darker skin tones?
Yes. Unlike some lasers, monopolar RF doesn't target melanin and is generally considered safe for all skin types and tones.

Can XERF replace a facelift?
No. XERF is for mild-to-moderate skin laxity. If you have significant sagging, jowling, or skin excess, surgery delivers results that no non-invasive treatment can match. XERF can be a good preventive treatment in your 30s–40s and a maintenance treatment after surgery.

How does XERF compare to Ulthera?
Different mechanisms — Ulthera uses focused ultrasound (HIFU), XERF uses radiofrequency. Ulthera reaches deeper (down to the SMAS layer reliably), but XERF treats more of the skin volume per session. Many Korean clinics use both as complementary treatments rather than alternatives.

Related Reading

• Korean Skin Treatments: Complete Guide
• Rejuran vs. Juvelook: Which Is Better?
• Korean Skincare Trip Cost Guide
• How We Vet Seoul Clinics
• Post-Treatment Recovery Protocol
• The Korean Anti-Aging Protocol