Nerves that transmit electrical signals from the brain to muscles are blocked by anti-wrinkle injections. At the end of the nerve, an anti-wrinkle product prevents the release of the chemical acetylcholine, which prevents the muscle from contracting. The anti-wrinkle product takes time (usually between five and fourteen days) to reach all the individual nerves and block the release of acetylcholine. The injections become more noticeable as acetylcholine is blocked more and more.