In its third decade of use, Botox is an excellent treatment for dynamic lines formed with muscle movement. Commonly injected areas are frown lines (between eyebrows), crows feet (smile lines), vertical lip lines and horizontal forehead lines. Excess sweating (hyperhidrosis) can also be treated effectively. Results are seen in days and last about three months, and repeat treatments can lengthen the effective period. There is no risk of botulinism, and side effects are quite unusual.