**10.5 Deoxycholic acid**

Deoxycholic acid (Kybella (USA) or Belkyra (Canada) Allergan Pharmaceuticals, Markham, ON, Canada) is an injectable treatment for subcutaneous fat excess, currently approved for improvement of submental fat. Deoxycholic acid induces adipocytosis and local inflammatory response to result in improved neck contour [24]. Off-label treatment of the upper arms with deoxycholic acid has been described [24], although to our knowledge no studies of large patient sizes, long-term results, and potential complications have been published. As one of the clinical trial centers for use of deoxycholic acid in the submental region, we have extensive experience with the product and its method of action. Given its localized treatment area, need for multiple treatments, significant post-treatment swelling, lack of improvement of skin quality, need for high volumes of product and corresponding cost, and residual subcutaneous fibrosis that can impair future surgical treatments (such as with liposuction), we do not recommend use of deoxycholic acid for arm contouring. Adverse neurotoxic effects of deoxycholic acid resulting in demyelination of nearby nerves with resultant anesthesia/hypesthesia of sensory nerves and weakness of motor nerves, is another limiting factor in broadened use of this drug in body contouring [24].
