It has been estimated that more than 40 million American women in the United States have unwanted facial hair. Like menopause, the story of unwanted facial hair is often all about estrogen, or to be more precise, the relationship between levels of estrogen and testosterone.

When estrogen predominates, a woman’s face typically has vellus hair –fine, short and almost invisible like ‘peach fuzz’. Men, in contrast, have terminal hair, the longer, coarser, darker beard-type hair. Unwanted facial hair can be different for every woman, from a few hairs on the chin, light growth on the upper lip or heavy and beard like growth. One woman may find the slightest growth on her lip or chin terribly bothersome, while another woman may have visible hair on her upper lip and it may not bother her at all. Women with excessive facial hair often experience psychological factors such as low self-esteem and embarrassment.

The key hormone that controls the type of hair on your face is dihydrotestosterone (DHT). Higher DHT levels cause your facial hair to convert from vellus to terminal hair production.

During reproductive years, the higher relative levels of estrogen to testosterone usually keep production of DHT low. However, as menopause approaches and estrogen levels drop, there’s an increase of DHT in the hair follicle (details below). It’s at this point many women begin to see frustrating ‘beard-like’ hairs in places they’ve never seen them before—chin, jaw line, cheeks, and even the forehead.

Over the years, good choices for solving the problem of unwanted facial hair have been fairly limited. If there’s just a bit of facial hair showing up, the common response is to control the problem by plucking with tweezers or with some gadget or contraption that tweezes automatically. The problem with that, however, is that plucking actually can stimulate the hair follicle into an active growth (anagen) phase in which hair growth is quicker and thicker… something you obviously don’t want. Choices beyond plucking have their limitations as well. Shaving leaves a bristle and 5 o’clock shadow, and is something you have to actively keep up with once you’re committed. Electrolysis is expensive and painful. Laser is expensive and can be uncomfortable. We all know how painful waxing can be. Plus the cost adds up over time. The list of frustrations with current treatment can be pretty long.

It is important to talk to your doctor about unexpected or rapid unwanted hair growth.