The same principles that make BOTOX® Cosmetic effective as a medical treatment make it effective as a cosmetic treatment. Injecting small amounts of BOTOX® Cosmetic into these active facial muscles results in localized paralysis and a smoother, more relaxed facial expression. Most commonly it is used in the upper face to eliminate frown lines and crow's feet. You can expect the results from BOTOX® Cosmetic to last 3-5 months.