FDA approves Liposonix noninvasive waist reduction

It’s been a long road with Liposonix since we first began to develop the technology here in the Seattle area several years ago, and the FDA’s approval last week for marketing in the U.S. was a long awaited milestone. Liposonix uses high-intensity focused ultrasound (HIFU) energy to “permanently destroy targeted fat” below the skin. Because the clinical trial on which the approval was based measured reduction in waist circumference as the endpoint, the technology can only be marketed for that, and treatment of other areas remains to be studied.
How does Liposonix differ from other treatments? One similar device called Ultrashape also uses focused ultrasound but has not been approved by the FDA. With HIFU, the specific effect on tissue depends on the frequency and energy as well as the focusing mechanism. The frequency used in Liposonix generates heat (thermal effect) in addition to disrupting fat cells, while the Ultrashape version has minimal thermal effect. The Liposonix frequency can be precisely focused and the thermal effect, in theory, could be a good thing. Ulthera, for example, also uses focused ultrasound but at a more superficial level to stimulate facial skin lifting through a thermal effect.
Another device is Zerona, which uses a low-energy laser that is supposed to poke little holes in fat cells so that fat can leak out. Importantly, it seems to work best when used with diet supplements and exercise. In contrast to Liposonix, there have been no published studies showing exactly what happens to the tissue in living human subjects with Zerona. That is a critically important point because laser energy cannot be focused to specific layers below the skin like ultrasound.
Radiofrequency energy, like Thermage, uses a purely thermal effect but also cannot be focused to a specific target like ultrasound.
So Liposonix represents the first FDA-cleared device for permanent fat reduction in a single treatment without injections, incisions, or downtime. It probably won’t replace liposuction just yet however, as the volume of fat removal that can be done noninvasively has limits. In Europe, where Liposonix has been in use for a couple of years, it is sometimes marketed with the promise of “one treatment, one hour, one size smaller.”