A woman is considered to be postmenopausal when she has not had her period for an entire year (assuming she is not on medications that can stop periods). Measuring through a blood test called the follicle stimulating hormone (FSH) level is another way to determine if you are postmenopausal. FSH is a hormone produced by the pituitary gland (located at the base of the brain). However, the routine use of the FSH test is not needed to help the vast majority of women. Sometimes, the levels can be misleading since the levels go up and down during the transition into menopause.