People have reported severe side effects, such as scarring, infections and skin deformities, after using unauthorized fat-dissolving injections in their chins, arms and stomachs.

The Food and Drug Administration issued a warning about the dangers of using unauthorized versions of fat-dissolving injections, saying it has received reports of severe side effects, such as persistent scarring, severe infections and skin deformities.

Fat-dissolving injections, sometimes called lipolysis injections, are nonsurgical procedures that aim to melt away small amounts of fat beneath the skin. These injections are typically administered in so-called problem areas such as the chin, legs, upper arms and abdomen.

The FDA has approved one such injection, a drug called Kybella, from Kythera Biopharmaceuticals.

However, the FDA on Wednesday noted the presence of unapproved fat-dissolving injections popping up at clinics and med spas across the U.S., including those sold online under brand names like Aqualyx, Lipodissolve, Lipo Lab and Kabelline.