Botox is so effective because it is the only wrinkle treatment that targets the underlying cause of wrinkles — the muscle.
It all starts with a nerve telling a muscle to contract. This causes the overlying skin to scrunch up. With time and repeated contractions, the skin begins to thin at certain points and a wrinkle is born.
Think of the skin as a piece of paper. By folding the paper along the same crease over and over, you are deepening/reinforcing that fold and weakening the paper.
Now imagine if all of a sudden you cannot fold the piece of paper. Instead, you flatten it out and place it between two large books. With time the fold fades. That is the same mechanism by which Botox is able to prevent/decrease the wrinkles of the face. The big distinction in the analogy, however, is that skin is a living organ that is able to regenerate. So with time and good skin care, wrinkles virtually disappear.
Botox’s competition include topical creams, which simply do not address the source of the wrinkle, and plastic surgery, which is very invasive, painful and requires general anesthesia. This is why Botox has earned the reputation as one of the best anti-wrinkle treatment available.