Body RF devices explained:
truSculpt, Vanquish and Exilis, and how Onda Pro and Secret Duo differ

What does body radiofrequency actually heat?

Radiofrequency is an alternating electrical current in the megahertz range. When it passes through tissue, the tissue resists it, and that resistance becomes heat. Different tissues resist differently: water-rich dermis and muscle conduct well, fat conducts poorly, so where the heat concentrates depends on the frequency chosen, the electrode design and whether the device touches the skin at all.

Three design families cover most body devices. Monopolar radiofrequency passes current from a handpiece on the skin to a return pad elsewhere on the body, so the current travels deep and heats a volume of dermis and fat. Contactless selective radiofrequency sets up a field between a panel and the body without touching it, tuned so that the fat layer absorbs proportionally more. Microneedle radiofrequency carries current through fine needles to a set depth and releases it at the tip. The three devices in this guide belong to the first two families; the devices in Dr Sin Yong's practice are discussed after them.

Whatever the design, the target temperature is the same idea: warm the fat enough for the fat cells to undergo apoptosis, programmed cell death, so that the body clears them gradually, and warm the dermis enough for collagen to contract and remodel, without burning the surface. Surface cooling, temperature sensors and the person's feedback are what keep that balance.

truSculpt: monopolar radiofrequency through contact applicators

truSculpt is Cutera's monopolar body platform. Earlier generations, truSculpt and truSculpt 3D, used a handpiece glided over the treatment area to a skin temperature in the mid-forties Celsius; the current truSculpt iD uses up to six flat applicators strapped onto the abdomen, flanks or thighs so that several zones are heated at once, at a frequency of 2 MHz. Because the current is monopolar, it travels through the full thickness of skin and fat to the return pad and heats both.

The published work is small but uses objective measurement. An ultrasound study of a single truSculpt 3D treatment on the abdomen and flanks reported a thinner fat layer at follow-up, and a two-site pilot trial of a monopolar 2 MHz applicator device on the same areas reported a thinner fat layer on ultrasound and blinded-investigator ratings of improvement. Side effects described were mild and self-limiting: warmth, redness and tenderness.

truSculpt iD holds a US FDA 510(k) clearance granted in July 2022 under product code GEI, the electrosurgical cutting and coagulation category that most monopolar aesthetic devices sit in. Clinics in Singapore that use it must hold the device on the Health Sciences Authority register; it is not a platform described on this site.

“Every body radiofrequency device heats something. The question I ask before any of them is which layer is actually the problem, because heating the wrong layer is not a milder version of the right treatment.”

Dr Sin YongOn Body RF devices explained

Vanquish: contactless selective radiofrequency

Vanquish is BTL's contactless body device. A curved panel of electrodes is positioned a short distance above the abdomen or thighs on a spacer, and the field between panel and body is tuned so that tissue with the impedance of fat absorbs more of the energy than the dermis above it. The person lies under the panel for the session and feels warmth; nothing touches the skin apart from the spacer.

The early series measured abdominal circumference after a course of treatments and reported a decrease in most participants, with the thinnest participants responding least, which the authors put down to there being too little fat for the field to heat. A later long-term follow-up of abdominal fat treated with the same device described the response as maintained in the people re-examined. In both, mild to moderate redness was the side effect reported. The circumference measure is a weaker outcome than imaging, so the evidence is less direct than the MRI and ultrasound data behind some other devices.

Because nothing contacts the skin, Vanquish has no direct action on the dermis; it is a fat device, not a tightening device. A person whose skin has lost recoil over the deposit is likely to look looser once the fat beneath is reduced, which is the recurring problem with any fat-alone treatment and the reason Dr Sin Yong examines the skin before the fat.

Exilis: cooled monopolar radiofrequency for skin and fat

Exilis is BTL's handheld monopolar platform, built to work on both the body and the face. A cooled handpiece is moved over the area while an energy-flow control adjusts the output to the tissue, and a cooling system protects the surface so that deeper heating can be sustained. Later versions, Exilis Elite and Exilis Ultra, added ultrasound energy to the same handpiece. The original Exilis Model 5000 was cleared by the US FDA in November 2009 under product code GEI.

The mechanism data come from a porcine study in which focused monopolar radiofrequency produced apoptosis in fat cells, and from veterinary work on collagen remodelling in skin treated with the same monopolar design. Clinical series on the body report circumference and photographic change; the device sits closer to Thermage and Volnewmer in principle than to Vanquish, because the handpiece touches the skin and heats dermis and fat together.

That dual target is also its limit. A cooled monopolar handpiece heats a volume of tissue rather than a fat pocket, so it is used where mild laxity and a thin fat layer coexist rather than where a compact, pinchable deposit is the problem.

Monopolar vs contactless vs microneedle RF: how the three designs compare

The question underneath the table

Which design suits a person is not a question about devices. It is a question about what is under the skin: a layer that pinches, skin that stays tented, or both. The RF devices compared page sets out the same logic for the face; on the body, the guide to sagging tummy, buttocks and arms gives the pinch-and-recoil test Dr Sin Yong uses.

How Onda Pro and Secret Duo differ from these three

Neither of the body platforms Dr Sin Yong uses belongs to the monopolar or contactless families above. Onda Pro is DEKA's Coolwaves platform and is not radiofrequency at all: it delivers microwave energy at 2.45 GHz, a frequency that fat absorbs preferentially over the dermis, through a cooled handpiece. The energy acts on the membranes of fat cells, on the fibrous septa whose tethering produces cellulite dimpling, and on dermal collagen, which is why it is applied to localised fat, cellulite and laxity on the body and, through a finer handpiece, to the face. Dr Sin Yong is a Global Key Opinion Leader for DEKA and his practice is a certified DEKA Centre of Excellence.

Secret Duo is the microneedle platform behind his 4K Body Lift. Insulated microneedles carry bipolar radiofrequency into the dermis and release it at the tip, so the surface is spared and the depth is chosen for the zone; on the body the deeper range is used because the dermis is thicker. The protocol is radiofrequency alone, with no electromagnetic muscle stimulation, and it is directed at a compact, pinchable fat pocket together with the skin over it. Secret RF was cleared by the US FDA in 2017 (K170325) and Secret Duo in 2021 (K202043), both filed by ILOODA; the platform is now distributed by CLASSYS, for whom Dr Sin Yong is also a Global Key Opinion Leader. The body-specific detail is on Secret Duo for the body.

For lax skin with little fat beneath, the protocol is the VF Lift – Vertical Figure Lift, Volnewmer 6.78 MHz monopolar radiofrequency applied along vertical vectors; where laxity and a thin fat layer coexist, Time Freeze Laser LCLR®, his dual-wavelength laser protocol; where the concern is fat alone, fat freezing is discussed.

Who should ask about which?

• A broad, soft layer across the abdomen with skin that springs back: a fat-layer question. Contactless selective radiofrequency is built for this; in Dr Sin Yong's practice the equivalent conversation is Onda Pro or fat freezing.
• A firm, pinchable pocket on the lower tummy, flank or inner thigh with skin starting to loosen over it: the 4K Body Lift on Secret Duo, because the deposit and the skin need treating together.
• Skin that stays tented after a pinch, with little fat beneath: a monopolar heating question. Exilis and Thermage belong here in principle; the body protocol here is the VF Lift – Vertical Figure Lift on Volnewmer.
• Laxity and a thin fat layer in the same zone, often after weight loss or pregnancy: Time Freeze Laser LCLR®, which addresses both.
• Marked excess skin after large weight loss, or abdominal separation: none of the above. Dr Sin Yong refers to a plastic surgery specialist, and says so at the first visit.

Any of these is decided at an in-person assessment rather than from a device name, and the response is reviewed before further treatment is planned. Suitability also depends on pregnancy, implanted electronic devices, metal in the field, active infection and healing tendency, which are checked for every energy device.

Regulatory status in Singapore

Energy devices used for aesthetic treatment in Singapore must be listed on the Health Sciences Authority's medical device register, and the clinic must be licensed under the Healthcare Services Act. A US FDA 510(k) clearance, cited above where it could be verified, establishes that a device is substantially equivalent to one already on the US market for a stated indication; it is not a measure of how well a device works for an individual, and the indication cleared is often narrower than the marketing. When a clinic names a device, the useful questions are which indication it is registered for, who operates it, and what examination decided that it fits.