When tiny amounts of Botox are injected into the facial muscles responsible for movement those lines that are wrinkles directly associated with the muscle movement are diminished by weakening of the muscle. Thus, Botox therapy works best for “dynamic” lines and wrinkles, and is less effective for fine textural changes on the skin surface, and for those lines present at rest.
Botox therapy is temporary, meaning it will have to be repeated on a regular basis to remain effective. An average response is 3 to 6 months of diminished muscle contraction, although there have been reports of more than 6 months of efficacy following a single injection. Individual responses may be longer or shorter depending on the degree of skin sun damage,depth of the lines, the size of the muscle,and the amount of Botox used in the location.