Thermage FLX tightens skin with radiofrequency, while ONDA uses microwave energy that also reaches stubborn fullness on the lower face. Here is how they differ and which concerns each one suits.
Thermage FLX uses monopolar radiofrequency to tighten skin and rebuild collagen in the dermis, usually in one session lasting 12–18 months. ONDA Lifting uses Coolwaves microwave energy that heats deeper fat and connective tissue, so it suits lower-face fullness, a heavy jawline or mild double chin as well as loose skin. Thermage is better for crepey skin and overall firmness; ONDA is better when volume along the jaw is part of the problem. At Dernia Clinic Myeongdong, Thermage FLX starts from ₩990,000 and ONDA from ₩199,000 (30,000 J), excluding 10% VAT.
Prices are in Korean won, exclude 10% VAT and are confirmed by a doctor at consultation.
Thermage FLX vs ONDA: what is the main difference?
Both are non-surgical, energy-based treatments for the face, but they use different energy and target different problems. Thermage FLX uses monopolar radiofrequency to heat the deep dermis, tightening the skin and stimulating collagen. ONDA Lifting uses microwave energy (DEKA's Coolwaves technology) that travels deeper, heating fat and the connective tissue beneath the skin while a cooled handpiece protects the surface.
In practice, Thermage is chosen mainly for skin quality and laxity, while ONDA is chosen when fullness along the jaw, jowls or under the chin is part of what makes the face look heavier. For a broader overview of devices used in Korea, see Korean lifting treatments explained.
How does Thermage FLX work?
Thermage FLX, from Solta Medical, sends RF energy through a single-use tip that measures the skin before each pulse. The heat makes existing collagen contract and prompts new collagen over two to six months. It is usually a single session, repeated every 12–18 months, and it can treat the eyelids with a dedicated tip. Read more on the Thermage FLX page.
How does ONDA Lifting work?
ONDA uses microwaves at a frequency designed to be absorbed mainly by fat tissue. The handpiece is moved in slow passes over the treatment area, delivering energy measured in joules. As the deeper layers warm, small fat pockets can reduce over time and the fibrous network beneath the skin tightens, which can make the jawline look cleaner. Results build over four to eight weeks, and many people choose two or three sessions. See the ONDA Lifting page.
On treatment day, the process is straightforward for both devices:
- English consultation. A licensed doctor looks at whether your concern is mainly loose skin, fullness or both, then agrees the device, energy or shot plan and the price with you.
- Preparation. The skin is cleansed. Thermage uses numbing cream for about 30–40 minutes; ONDA may use a lighter preparation, depending on the area.
- Treatment. Thermage is delivered pulse by pulse over a marked grid. ONDA is applied in slow, overlapping passes with continuous surface cooling until the planned energy has been delivered.
- Soothing and aftercare. Redness and warmth are calmed, and you leave with written aftercare in English and a contact for questions.
Side-by-side comparison
| Factor | Thermage FLX | ONDA Lifting |
|---|---|---|
| Energy | Monopolar radiofrequency | Microwave (Coolwaves) |
| Main target | Dermis and collagen | Fat and deeper connective tissue |
| Best for | Loose, crepey skin; eyelids; overall firmness | Lower-face fullness, jowls, double chin, small body areas |
| Session time | 45–90 minutes plus numbing | 20–40 minutes |
| Sessions | Usually one | Often 2–3 |
| Downtime | None to minimal | None to mild swelling |
| Results | Build over 2–6 months; last ~12–18 months | Build over 4–8 weeks |
Key benefits of each treatment
Thermage FLX benefits
- One session is usually enough, which suits a short trip.
- Improves skin quality: firmer, smoother and less crepey skin.
- Eyelid option for mild hooding and crepiness.
- Long-lasting compared with most non-surgical devices.
ONDA Lifting benefits
- Addresses fullness that skin-tightening devices do not, such as soft jowls or under-chin fat.
- Shorter appointment and generally comfortable thanks to surface cooling.
- Can treat small body areas, such as the upper arms.
- Lower starting price per session.
Which is right for you?
Usually a good fit
- Thermage: thin or crepey skin, mild sagging, early lines, eyelid hooding
- ONDA: heavy lower face, soft jowls, mild double chin, blurred jawline
- People who want little or no downtime
Talk to the doctor first
- Very slim faces with little fat (ONDA may not be suitable)
- Pacemakers, implanted electronic devices or metal implants in the area
- Pregnancy or breastfeeding
- Significant sagging that may need a surgical opinion
Many faces have both looseness and fullness. In that case, a doctor may suggest combining approaches across visits. See options for jowls and double chin treatments.
Results timeline
With Thermage, you may notice a fresh, slightly firmer look on the day, early change around one month and the main result at three to six months as collagen matures. With ONDA, the change is more gradual at first: mild swelling may hide the effect for a few days, and contour changes usually become visible over four to eight weeks. Both results depend on age, skin quality, weight stability and lifestyle. Because the peak of either treatment usually arrives after you are home, take clear photos in the same light before treatment and again at one, two and three months so you can judge the change fairly. Significant weight gain can offset ONDA's contouring effect, and daily sun exposure speeds up collagen loss after Thermage. Typical timelines are on the Thermage FLX results and ONDA results pages.
Is it safe? Risks and side effects
Both devices are considered low risk when used by trained medical staff with appropriate settings. Common effects include redness, warmth and mild swelling for a few hours to a few days. ONDA can cause temporary tenderness, firmness or numbness in the treated area. Thermage may cause temporary tenderness over bony areas, and uncommonly small blisters. Rarely, any heat-based device can cause burns, nerve irritation or uneven contour, especially if energy is too high in thin areas, which is why a doctor should select settings for your anatomy. Because ONDA targets fat, it is not suitable where there is little fat to begin with, and over-treatment could leave the face looking hollow.
Contact the clinic promptly if you notice blistering, worsening pain, persistent numbness or a hard, painful lump, even after you have flown home.
How much do Thermage FLX and ONDA cost in Seoul (2026)?
| Treatment | Plan | Price (KRW) |
|---|---|---|
| Thermage FLX | 300 shots, face | ₩990,000 |
| Thermage FLX | 600 shots, full face and jawline | ₩1,690,000 |
| ONDA | 30,000 J, under the chin or jawline | ₩199,000 |
| ONDA | 60,000 J, lower face, jawline and under the chin | ₩349,000 |
| ONDA | 90,000 J, lower face with extra passes | ₩490,000 |
Prices exclude 10% VAT and are confirmed at consultation. The tourist VAT refund on cosmetic procedures ended on January 1, 2026. Full details: Thermage FLX price and ONDA price.
Planning Thermage or ONDA around your Seoul trip
- Book ahead. Send your dates and photos of your concerns through the consultation form so a plan can be suggested before you arrive.
- Avoid arrival day. Plan treatment for day two or later.
- Multiple sessions. If ONDA is recommended as a series, the first session can be done on this trip and later ones on a return visit.
- Getting here. Dernia is near Myeongdong Station (Line 4) and Euljiro 1-ga Station (Line 2).
Flying home? Neither treatment involves needles or wounds, so most people can fly the next day. Mild swelling after ONDA may last a few days; avoid saunas and alcohol for a day or two. See our aftercare guide.
Frequently asked questions
Is ONDA radiofrequency?
No. ONDA uses microwave energy, which is absorbed mainly by fat tissue, whereas Thermage uses radiofrequency that heats the dermis.
Which is better for a double chin?
ONDA is usually the better fit for mild under-chin fullness because it targets fat. Thermage mainly tightens skin and does not reduce fat.
How many ONDA sessions do I need?
Many people choose two or three sessions several weeks apart. Your doctor recommends the energy and number of sessions after examining you.
Does ONDA hurt?
Most people feel deep warmth that is manageable thanks to the cooled handpiece. Sensitivity can be higher over bony areas.
How much do they cost at Dernia?
Thermage FLX starts from ₩990,000 for 300 shots and ONDA from ₩199,000 for 30,000 J, excluding 10% VAT.
Can I combine Thermage and ONDA?
Some people benefit from both, since they target different layers. Your doctor will advise whether and when to combine them.
Thermage FLX or ONDA for your face?
Send us your concerns and travel dates. A doctor examines your face in person, explains which option suits you in English and confirms your plan and price first.
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This article is for general information and does not replace a medical consultation. Results vary between individuals, and suitability, treatment plan and final price are confirmed by a licensed doctor after an in-person examination. Dernia Clinic Myeongdong does not publish patient testimonials or before-and-after claims.