Anatomy, not age

While age is not an insignificant factor, it is the anatomy and the resultant desired look that will determine appropriateness of a procedure. Of course if you look at infants and toddlers, many of them have "droopy" brows but as an adult the analysis of the anatomy and the emotional reaction to your own look will point you in the correct surgical direction. Be sure it is the brow position that is the problem and not just the skin or fat below the brow that you are referring to.