Anti-Mullerian Hormone (AMH), also known as Mullerian Inhibitory Substance, is a hormone secreted by the small follicles on the ovary. These small follicles will eventually grow into mature follicles that will contain the egg released during ovulation. Some doctors use this test as an indication of ovarian reserve or function. Additionally, AMH is typically found to be elevated in patients with PCOS. According to a study found in Clinical Endocrinology, women with PCOS who do not get their periods have higher levels of AMH, then women who get a period infrequently. It appears that AMH levels may soon play a role in diagnosing PCOS. Ask your doctor if you may benefit from having this test done.