Botox® works by temporarily weakening the muscles that contract to cause wrinkles. It’s FDA-approved for treating crow’s feet (or laugh lines), the creases between the brows and forehead lines. There are other FDA-approved medications that work similarly: Dysport® and Xeomin®. But Botox® is the market leader with about 90 percent of treatment targeting the upper face. We prefer it because it’s predictable and we know it works.