Botox is a purified substance injected into specific muscles of the face to smooth wrinkles.   It is FDA approved and has been in use since 1980.   Botox mainly is used for wrinkles between the eyebrows, but it is also used for wrinkles across the forehead, outer "crow's feet", wrinkles around the mouth, as well as the muscle bands often visible on the neck, commonly known as "turkey neck."   Treatments generally are very effective and results last approximately 4 months. With multiple treatments, re-treatments may be needed less often.   The procedure is simple with minimal discomfort. There is no down-time.   Side effects are rare and reversible. They include headache, bruising, redness and droopy eyes.   Botox is often combined with other cosmetic treatments for greater effects. Botox is also FDA approved to treat excess sweating, or hyperhidrosis, of the palms or underarms.