Can follicle stimulating hormone (FSH) levels predict postmenopause onset?

If you are in perimenopause, your levels of follicle stimulating hormone (FSH) are still fluctuating widely. So a single blood test result showing elevated FSH could represent just one part of a given menstrual cycle.

I will tell you what I tell my perimenopausal patients: you can have your blood drawn one day and get an FSH result that looks like a 20-year-old's (a low number), yet on another day that same week you could get a result that looks like a 60-year-old's (a high number). These erratic results may reflect your perimenopausal status, but do not predict whether postmenopause is imminent. In postmenopause, FSH is consistently elevated, but this rise does not begin until one year after your final menstrual period.