It targets the underlying cause of frown lines, crow's feet, and forehead lines. The repeated muscle contractions from frowning, squinting, smiling, and raising the eyebrows over the years cause these lines that stay, and the neurotoxin breaks up the synthesis of the proteins that make that muscle move.

So basically temporarily not allowing the muscles and the proteins to communicate. That's kind of an over simplistic way of saying it. There is no FDA-approved substitute for neurotoxin that is effective or technically interchangeable.