Botox. It's more than just a wrinkle buster.
The blockbuster product is at the center of Valeant Pharmaceuticals' hostile play for Allergan, valued at $45 billion to $50 billion. Irvine, Calif.-based Allergan projects sales of Botox will rise to as much as $2.28 billion this year.
A little known fact: More than half of that revenue comes from therapeutic uses of Botox, rather than from cosmetic ones.
In addition to smoothing wrinkles between the eyebrows and crow's feet around the eyes, Botox is approved for uses like migraines and incontinence. And Allergan is testing it in additional therapeutic areas including depression, pain and juvenile cerebral palsy.
As Allergan CEO David Pyott has put it, Botox is an entire pipeline in a single product.
—By CNBC's Meg Tirrell.