Botox is a trade name for botulinum toxin, which comes in the form of a purified protein. The mechanism of action for Botox is really quite simple. Botox is injected into the facial muscles but really doesn’t affect the muscle at all. Botulinum toxin affects and blocks the transmitters between the motor nerves that innervate the muscle. There is no loss of sensory feeling in the muscles. Once the motor nerve endings are interrupted, the muscle cannot contract. Botox is a muscle relaxer. When that muscle does not contract, the dynamic motion that causes wrinkles in the skin will stop. The skin then starts to smooth out, and in approximately three to ten days after treatment, the skin above those muscles becomes nice and smooth. The effects of Botox last for approximately three to four months, at which time the patient needs retreatment.