The onset of menopause, either surgical or natural, is characterized by a gradual decline of the hormones estrogen, progesterone and testosterone. Reduced estrogen levels can lead to vaginal dryness, which in turn may result in painful intercourse. Reduced testosterone levels, in some women, may lead to a decline in libido. While testosterone is widely considered the "male" hormone, because it is responsible for masculine characteristics like facial hair and a deep voice, it is also present in much smaller amounts in women. Like estrogen, testosterone is produced by the ovaries and adrenal glands and declines gradually throughout a woman's life. Testosterone replacement therapy is currently a controversial treatment because the efficacy and safety in women has not yet been determined.