Botox injections temporarily prevent a muscle from moving to reduce the appearance of facial wrinkles. It may also help prevent chronic migraine and hyperhidrosis from underarms and hands. Botox injections block certain chemical signals from nerves, mostly signals that cause muscles to contract. These injections are used to temporarily relax the facial muscles that cause wrinkles in the forehead and around the eyes. Botox is also used to treat conditions related to certain body functions such as: Lazy eye and eye twitching