Quick answer:
ONDA is a microwave-based device that delivers energy into the fat layer under the skin to reduce small pockets of facial fat and tighten mild laxity. Clinics in Seomyeon commonly use it for the lower face, jowls and double chin. Results are gradual, usually need several weeks to appear, and vary between individuals.
What ONDA Is
ONDA is a device made by the Italian manufacturer DEKA. Instead of ultrasound (like HIFU) or radiofrequency (like Thermage), it uses microwave energy at 2.45 GHz, marketed as "Coolwaves" technology. Because fat contains relatively little water compared with skin and muscle, the energy is designed to concentrate heat in the subcutaneous fat layer while contact cooling protects the skin surface.
ONDA was first developed for body contouring. Korean clinics then adopted smaller handpieces for the face, where it became popular for slimming a full lower face without injections or surgery. Aesthetic devices in Korea must be approved by the Ministry of Food and Drug Safety (MFDS), so it is reasonable to ask a clinic to confirm that its unit is a genuine, approved system.
How Microwave Energy Affects Fat and Skin
Fat reduction
When fat cells are heated to a certain temperature for long enough, some are damaged and gradually cleared by the body over the following weeks. The effect is modest and localized: ONDA is not a weight-loss treatment and does not replace liposuction for larger fat volumes.
Tightening
Heat in deeper layers can also stimulate collagen remodeling in the connective tissue running through fat. Some people notice slightly firmer contours, but tightening is usually secondary to slimming and less predictable.
Common Facial Treatment Areas
- Double chin:
one of the most requested zones, especially when a small fat pad blurs the jawline.
- Jowls and lower cheeks:
to soften heaviness along the jaw.
- Body areas:
abdomen, flanks, arms and thighs with larger handpieces.
Areas where volume is already low, such as hollow cheeks or temples, are generally avoided because reducing fat there can make the face look older or more tired.
Who May Be a Good Candidate
ONDA tends to suit adults with a localized area of facial fat and reasonable skin elasticity. People in their twenties and thirties with a round, full lower face are frequent candidates, as are people in their forties with early jowling caused partly by fat. The doctor should distinguish between fat, muscle bulk, swelling, bone structure and laxity, because each needs a different approach. A wide jaw caused by the masseter muscle, for example, responds to botulinum toxin rather than fat reduction.
Who should be cautious or avoid it
- People who are pregnant or breastfeeding
- Anyone with a pacemaker or other implanted electronic device
- People with metal implants or certain fillers in the treatment area, unless assessed by the doctor
- Those with active infection, open wounds or inflammatory skin disease in the area
- People with very thin faces or significant sagging, where fat loss could worsen the appearance
What a Session Is Like
- Assessment and marking.
The doctor pinches the fat to judge thickness and marks the zones.
- Treatment.
The handpiece moves continuously over each zone while the device cools the skin. Energy is counted in kilojoules (kJ), and the doctor sets the dose by area.
- After treatment.
Mild redness and warmth are common, and most people return to normal activities the same day.
The sensation is often described as building warmth with moments of sharp heat. Tell the practitioner immediately if any spot feels painfully hot, because burns are a recognized risk of heat-based devices.
Results Timeline
- First days:
slight swelling may make the face look fuller rather than slimmer.
- Two to four weeks:
early changes may start to show.
- Six to twelve weeks:
results are usually easiest to judge.
Some clinics recommend more than one session spaced several weeks apart, depending on fat thickness and response. Some people see a clear change; others notice little. Weight gain can offset results, because remaining fat cells can still enlarge.
Side Effects and Risks
- Redness, warmth and mild swelling for hours to a few days
- Tenderness or small firm areas in the treated fat, generally temporary
- Tingling or temporary numbness
- Rarely, burns, blistering or fat irregularities
- A hollow look if an area is over-treated
Contact the clinic promptly if you develop a blister, a painful hard area, or uneven contours that do not settle.
What Drives the Cost
Clinics usually price ONDA by area or by energy delivered in kJ, so two quotes for "one session" may not be comparable. Cost drivers include the number of zones, total kJ, who performs the treatment, bundling with other devices, and whether follow-up checks are included. Ask for a written, itemized quote listing areas, energy and VAT.
Fitting It Into a Busan Trip
Since downtime is usually minimal, ONDA can fit into a short stay. Have the session early in your trip so you can return if anything concerns you. Because the final result appears after you get home, take clear before photos in consistent lighting to compare later.
Frequently Asked Questions
Is ONDA the same as InMode?
No. ONDA uses microwave energy, while InMode facial handpieces mainly rely on radiofrequency. Both aim to reduce fat and tighten, but the energy type and sensation differ.
Does ONDA permanently remove fat?
Destroyed fat cells are cleared by the body, but remaining cells can grow with weight gain, so lasting results are not guaranteed.
Can ONDA make my face look older?
It can if fat is removed from areas that need volume. Careful assessment and conservative dosing reduce this risk.
Key Takeaways
- ONDA uses 2.45 GHz microwave energy to target facial fat and mildly tighten tissue.
- It suits localized fat with reasonable elasticity, not significant sagging or low-volume faces.
- Results build over six to twelve weeks and vary between individuals.
- Confirm the device is genuine and MFDS-approved, and compare quotes by area and kJ.
Medical disclaimer: This article is for general education only and does not replace a consultation with a licensed physician. Treatment suitability, results and risks vary by individual. In an emergency in Korea, call 119.
Last reviewed: October 2026.
