Botox ® is actually just the brand name for a substance called Botulinum Toxin. It has been used for decades in both aesthetic and general medicine, and is a well-tolerated, safe and effective treatment. It works by blocking nerve signals in muscles and therefore reducing movement in those muscles that have been targeted. In places like the crow’s feet or forehead this results in fewer wrinkles, but in areas such as the masseter (jaw muscle) it results in a reduction in size of the muscle.