Botulinum toxin type A is what makes Botox 100IU Injection work. It’s being used more and more to treat spasms and other nerve problems. Clostridium botulinum is the name of the bacteria that make it. To treat stiff muscles, wrinkles, and fine lines, Botox 100IU Injection is applied deep into the skin or into the muscles that need it. It briefly loosens up the muscles that make the forehead and eyes wrinkle.