A variety of factors are responsible for the drooping of the eyebrows as part of the facial aging process. Skin elasticity and skin texture also influence the resistance of the tissue to external factors such as gravity. With increasing loss of skin elasticity, horizontal forehead wrinkles often increase in size from as early as age 30. These are usually still very amenable to Botox treatment.

As aging progresses, the outer side of the brow facing the temple can be expected to drop, and later the middle and nasal part of the brow can be expected to drop as well. The tissue located under the upper layer of skin (so-called subcutaneous tissue), although attached to the bony orbit, yields to the weight and continues to sink. This gives the impression of a "low-hanging" eyebrow (so-called brow ptosis).

As the forehead wrinkles progress, the excess skin, which accumulates more in the upper eyelid, is accentuated. This leads to a tired and aged appearance of the brow/forehead area and to the impression of deeper-set smaller eyes.

The excess skin can be corrected by making an incision directly above the eyebrow.