When London-based plastic surgeon Mo Akhavani recently told British newspaper The Sun that he believed the Brazilian butt lift is one of the most dangerous plastic surgery procedures available, many patients around the world were surprised.

The procedure has recently soared in popularity thanks to the famously curvy backsides of celebrities such as the Kardashian sisters. In fact, in 2016 alone, Brazilian butt lift procedures were up by 252 percent over the previous year. But the question remains: How safe is the procedure, and is it really among the most dangerous of them all?

“The Brazilian butt lift certainly can be dangerous if it’s not performed by someone who knows how to do it, but in the hands of an experienced surgeon, the risks are about the same as any other procedure,” said Dr. Bruce Chau of Berkley, Michigan.

According to Chau, the danger lies in the fat transfer portion of the procedure.

“Some procedures use fillers to make the buttocks bigger, but that can look and feel unnatural, and there is a higher chance of side effects or the body rejecting the fillers if they are foreign,” Chau said. “When you use your own body fat as a filler, there is no chance of rejection, but if you accidentally inject the fat in the wrong place, such as a muscle, it can cause serious complications or even death.”

Chau doesn’t believe the risk of such a complication is abnormally high with a trained practitioner, but as always patients should be sure to use only licensed and board certified plastic surgeons.

“It seems like an easy enough procedure, to just inject body fat into the buttocks,” Chau said. “But you have to know where to extract the fat from, how to extract it safely, and where to inject it back into the body. It’s a far more complicated procedure than it seems.”