As a neurotoxin, when used at the prescribed dilution, Botox has a paralytic effect on the muscles adjacent to where injections are made. Facial wrinkles, caused by the muscles continually working to form smiles, frowns and various other facial expressions, become more pronounced as you age, often making you look older than you’d like. The introduction of Botox into these muscles causes them to relax and soften and simultaneously blocks the nerve impulses to them, taking away their ability to contract. Areas where improved appearance is most noticeable are the forehead, around the eyes and mouth and the neck. It should be noted, however, that the use of Botox will not have noticeable effects on wrinkles caused by gravity or by sun damage.