Imagine your muscles are like little engines that need fuel (a chemical called acetylcholine) to start working. Normally, your nerves send this fuel to your muscles every time they need to contract or move. Botulinum toxin works by blocking the fuel line; it stops your nerves from sending the fuel to the muscles. Without this fuel, the muscles can't start up and contract, which makes them relax and soften. This relaxation helps smooth out wrinkles on the face, making the skin look smoother and more youthful.