Celebrities like Khloé Kardashian and Molly Sims have sworn by cryolipolysis – a noninvasive procedure that uses extremely cold temperatures to reduce fat – to sculpt their bodies without going under the knife. But the popular technique, often referred to by one brand — CoolSculpting — may actually cause new fat growth in rare cases.

According to a study published in JAMA, fat freezing procedures may lead to paradoxical adipose hyperplasia, an enlargement of the treatment area. This effect was rarely reported, and the study concluded that the incidence was only 0.0051 percent.

However, a follow-up study published in Lasers in Surgery and Medicine found that the occurrence of this adverse effect are likely underreported. The study concluded that the incidence of paradoxical adipose hyperplasia is 0.47 percent or 2 in 422 cryolipolysis treatments – 100 times greater than the device manufacturer’s reported incidence.

Dr. Robert Rey performs cryolipolysis on his patients, and says he has not seen any growth caused by the procedure on those he has performed it on.

“It is a very rare occurrence,” the former Dr. 90210 star tells PEOPLE. “It appears to be rare enough that the majority of patients should not be concerned. It is non-invasive, does not require anesthesia, and there is no recovery period. It normally has good results, so it is a good alternative to liposuction.”

Rey says he plans on continuing to perform fat freezing procedures.

“As long as the patient is informed of the rare possibility, then I would proceed,” he says. “If [paradoxical adipose hyperplasia] were to occur, liposuction would be indicated to repair it.”

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However, Dr. Richard Ellenbogen, CEO of Beverly Hills Body, tells PEOPLE he has shied away from using CoolSculpting in his own practice.

“I have heard [from colleagues who use CoolSculpting] that in some cases the fat does increase in volume or the area becomes lumpy or uneven, and that even with repeated applications no discernable result can be seen,” he says.


Ellenbogen recommends liposuction as the most effective means of getting rid of unwanted fat.

“Liposuction does a much better job of removing the fat, and can be done under local anesthesia as an outpatient,” he says. “In most cases, patients can be back to work in a few days.”