The follicle-stimulating hormone test is an ovarian reserve test that measures the amount of FSH in the blood. Follicle-stimulating hormone (FSH), with luteinising hormone (LH), assists with adequate follicular development and growth. FSH is a significant gonadotropin hormone produced by the pituitary gland under the influence of gonadotropin-releasing hormone (GnRH) from the hypothalamus. The FSH test has different concerns depending on whether you are a child, female or a male.