Frown lines are caused by the contraction of muscles above the eyebrows and nose.

Initially they only appear when somebody uses these muscles but eventually the repeated contraction of these muscles leads to lines or wrinkles that are present even at rest. Like any other muscle, the more the frown muscles are used the stronger they become. Frowning can become a habit and often people are not even aware they are doing it. In addition, some people have a constant low grade muscle contraction in the frown area and are basically frowning constantly. These lines can make people look angry or stressed even when they don't feel this way.

Reducing severity of frown lines causes a more pleasant, approachable appearance.