What is FSH?
Follicle-stimulating hormone (FSH) is a hormone produced by a small gland inside your head called the anterior pituitary. FSH is released in response to another hormone called gonadotropin-releasing hormone, which is secreted by your hypothalamus.
Your pituitary gland also releases luteinizing hormone (LH). Both FSH and LH are gonadotropin hormones, which means that they tell the ovaries and testicles to secrete other hormones such as progesterone, estradiol, testosterone, and inhibin. These hormones play important roles in human reproduction and fertility.