Anti-wrinkle injections are made up of a substance called botulinum toxin.
When this is injected into the skin, it blocks the signals from the nerves to the muscles. As a result, muscles are relaxed and can no longer contract as much as usual which leads to an improvement in the appearance of your lines and wrinkles. This effect lasts approximately three to four months before the botulinum toxin is broken down by the body, muscles start to move again and you start noticing the reappearance of your lines and wrinkles.