Botulinum toxin injections are used to relax the fine muscles around the eyes, between the eyebrows and forehead, that are responsible for your frown lines and deep wrinkles. Treatment consists of a number of tiny injections with a very fine needle directly into the muscle. The effects of the injections begin to appear within a few days. Keep in mind that the results generally last for four to six months, after which time the injections must be repeated.