There are many factors that can cause forehead wrinkles.
However, the major cause for forehead wrinkles is the activity of the frontalis muscle which elevates the eyebrows and therefore causes wrinkles across the forehead.
As many women and men with mature skin will attest, age is also a factor. "Over time, excess motion, gravity and skin laxity will cause fine lines and wrinkles to form.
Neuromodulators such as Botox are professionally recognised as the best ways to alleviate forehead wrinkles. Botox and similar treatments help stop the muscle from working therefore getting rid of the crease.