What is it?  A neurotoxin derived from Clostridium botulinum that temporarily relaxes muscles, reducing dynamic wrinkles.

Discovered: First identified in the 19th century as a bacterium; its aesthetic applications were FDA-approved in 2002.

Applications: Reduces dynamic wrinkles (forehead lines, frown lines, crow’s feet), treats excessive sweating (hyperhidrosis), and softens jawlines (masseter reduction).