To determine infertility, the amounts of Luteinizing hormone (LH) and Follicle-stimulating hormone (FSH) as well as other hormones (progesterone and estrogen) are measured in both men and women. LH and FSH levels can help determine whether the male or female sex organs (testicles or ovaries) are working properly.

Women may also have the FSH and LH blood test ordered to determine what may be causing menstrual irregularities or to either predict or confirm the start of menopause.