Allergan (AGN) announced today that it will buy Kythera Biopharmaceuticals, Inc. (KYTH) for $2.1 billion or $75 per share as a cash and equity type deal, dependent on customary closing conditions. The shareholders of Kythera will receive 80% cash and the remaining 20% will be in Allergan common stock. 

The main reason for Allergan acquiring Kythera was to acquire an injection drug known as KYBELLA which is the first and only approved aesthetic drug for contouring moderate to severe submental fullness -- typically known as double chin. The injection drug has already been approved by the FDA on April 29, 2015. Other countries with pending approval are Switzerland, Australia, and Canada. 

Submental fullness changes a harmonious facial appearance that leads patients to look older than they really are. Roughly 67% of patients are bothered with their submental fullness indication, which means that this first to be approved drug may be able to change patients' lives. 

Also appealing to Allergan, Kythera has another clinical candidate known as KYTH-105 being developed to treat male pattern baldness, and other pre-clinical candidates as well.