How does a botulinum toxin injection work?
Botox works by blocking the release of an important chemical, known as acetylcholine, at the connections between nerves and muscles. This prevents the muscles from contracting and allows them to remain in a relaxed state. The effects can take a few days to become apparent as the muscle gradually relaxes. The effects are generally temporary as the nerve cells gradually grow new connections to the muscles. This can take three to six months.