Two- Four Months
Botox blocks the release of acetylcholine which normally would travel from the nerve ending to the muscle. Without acetylcholine, the muscle is inactivated and can no longer functiion. It becomes paraylyzed and relaxes. This causes the relaxation of the affected muscle(s) and the disappearance, or at least the diminution, of wrinkles.
Gradually, the nerve finds ways to get around that blockage and the acetylchoine is no longer blocked. It takes 2-4 months before that happens. When...