You may have heard about non-invasive liposuction techniques like Zeltiq and Liposonix that promise to dissolve fat without surgery or downtime. Though traditional liposuction is still the gold standard, these procedures do offer some benefits and may be the right choice for fat reduction for some, according to Lance H. Brown, MD, owner of a private practice in NYC and assistant clinical professor of dermatology at NYU’s School of Medicine. “The results of these two procedures can’t compete with traditional liposuction — it’s like comparing a bicycle to a motorcycle — but if you want to avoid surgery, these may be a good choice,” he says. “Zeltiq and Liposonix work best on small pockets of fat that you can’t lose, no matter how much you diet and exercise.”

While both procedures fall under the umbrella of non-invasive liposuction, they use different mechanisms to destroy the fat cells. Liposonix uses sonic technology to destroy the fat cells, while Zeltiq, also known as Cool Sculpting, freezes the fat to destroy it. In both instances the dead fat cells are naturally removed through the body’s immune cells and processed by the liver, and the resulting fat loss is seen in weeks to months. Read on to learn more about the differences in these non-invasive-liposuction procedures.

Liposonix

“Liposonix uses high-intensity focused ultrasound to noninvasively heat fat to 55 degrees Celsius,” explains Anne Chapas, MD, a board-certified dermatologist and dermatological surgeon in New York City. “The body’s immune cells then eliminate this fat through a natural process, called macrophage.” Lipsonix patients typically lose 2.5cm or one pants size after one treatment, she says. It is FDA cleared for circumferential reduction on the abdomen and flanks — including the love handles — and the results are seen in about six to 12 weeks. In addition to the abdomen and flanks, doctors often also use it for fat on the lower back, the back of the arms or “bra fat,” and the jowls.

The ideal Liposonix patient is close to his or her ideal body weight with a BMI of 30 or under and is in good overall health. You must be able to “pinch an inch” or 2.5cm of fat in the area to be treated.

During the treatment, which lasts about 30 to 60 minutes, the doctor will move the Liposonix device around the treatment area. You may feel discomfort, cold, prickling, tingling or warmth. After the treatment, you may feel mild pain, or experience bruising, redness or swelling. If you know that you have a low threshold for pain, you may want to ask your doctor about taking pain medication prior to the procedure.

Results are seen after one treatment in about six to 12 weeks.

Zeltiq

Zeltiq, also known as Cool Sculpting, uses cooling panels to freeze fatty tissue, which triggers a cell-death process known as apoptosis, explains Chapas. Dead fat cells are then cleared by the body. “The goal is to cool fat selectively without harming the healthy tissue, surrounding cells and the skin,” says Brown. Studies have measured a 22 percent reduction of fat thickness after one treatment. It is FDA cleared for circumferential reduction on the flanks.

During the procedure, a device with cooling panels is strapped onto the area that is being treated. In the first few minutes, you may feel an intense cold feeling that usually goes away. After, you may experience redness, minor bruising, tingling, numbness or discomfort in the treated area. Zeltiq is thought to be less painful than Liposonix, says Brown.

Results are seen in about eight to 16 weeks, and it may take up to three treatments to see full results.

The Downsides of Non-Invasive Liposuction

There are no current studies showing how long the results for Zeltiq or Liposonix last, but in theory, it should be permanent. “Since the fat is removed, the results should last a long time if people maintain a healthy lifestyle,” says Chapas. Brown agrees: “Think of it like washing a window,” he says. “If you don’t take care of it, it’s going to get dirty again.”

While Liposonix and Zeltiq do provide measurable results, they are not, however, risk-free. One concern is that because the results are instantly visible, as they are in traditional surgical liposuction, doctors have less con