Menopause
The menopause transition typically begins between 40 and 50 years of age (average 47.5). The duration of perimenopause may be for up to eight years. Women will often, but not always, start these transitions (perimenopause and menopause) about the same time as their mother did.
Female promiscuity
It is common for sex drive to diminish dramatically after menopause. A number of studies, including Alfred Kinsey's, have concluded that the average age group in which women are the most active sexually is their mid-thirties, one study liberally estimating 27-45 as the limits of the age group (the average man peaks earlier). Women in this age group typically report having sexual fantasies greater in number and intensity, engaging in sexual activity more frequently, and being more interested in casual sex.