NEW YORK (AP) _ Botox maker Allergan Plc. is buying Kythera Biopharmaceuticals for about $2.1 billion, adding an injection that reduces “double chin” to its portfolio of products.

The Dublin drugmaker will pay $75 per share in a cash-and-stock deal for Kythera, based in Westlake Village, California. The deal marks a 25.5 percent premium over Kythera’s closing stock price Tuesday.

Kythera Biopharmaceuticals Inc. is preparing to launch its double chin treatment Kybella in the U.S., and the company is seeking approval in foreign markets as well.

Kybella would fit comfortably in Allergan’s line of cosmetic injections. Botox is used cosmetically to prevent wrinkles, and the company’s Latisse promotes eyelash growth.

Kythera’s pipeline of experimental products includes setipiprant, aimed at preventing male pattern baldness.

Allergan was bought by Actavis for about $70.5 billion earlier this year. After completing the buyout, it opted to name the new combined company Allergan.