How Botulinum Toxin Blocks Nerve Signals

Know the mechanism before you treat: botulinum toxin stops the nerve signal that tells a muscle to contract.

A blocked signal at the muscle

The American Society of Plastic Surgeons states: "Injections of botulinum toxin block the nerve signals to the muscle in which it was injected." That is the plain version. The Cleveland Clinic's page on botulinum toxin injections covers the same treatment.

The mechanism, step by step

Wikipedia gives the detail. The toxin "prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction", thus causing "flaccid paralysis". Read it as three steps.

1. The toxin is injected into a muscle.
2. It stops acetylcholine from being released at the neuromuscular junction.
3. The muscle cannot contract.

The American Society for Dermatologic Surgery has a page on neuromodulators.

What to check on your own license

Before you inject, confirm your license and your employer's protocol allow it. For a product-level read, see the MedlinePlus entry on prabotulinumtoxinA-xvfs injection.