A combination of factors can cause facial lines. It's not just about the cellular changes that may occur, or reduction of collagen, or damage caused by free radicals from the sun and the environment. Repeated muscle contractions from frowning, squinting, or raising eyebrows can cause the skin to furrow and fold, gradually resulting in the formation of facial lines. 

• BOTOX® Cosmetic works beneath the surface and temporarily reduces the underlying muscle activity that causes moderate to severe frown lines, crow's feet, and forehead lines in adults to help them look visibly smoother.

• Patients may begin to notice a visible smoothing of frown lines, crow's feet, and forehead lines within 24 to 48 hours, with results lasting up to 4 months for moderate to severe frown lines in adults.