AMH, or Anti-Müllerian Hormone, is a substance produced by the ovaries in females. It plays a crucial role in regulating the development of ovarian follicles, which are essential for fertility. The level of AMH in the blood can provide insights into a woman's ovarian reserve, indicating how many eggs she may have left. In males, AMH is produced by the testes and is important for male sexual differentiation during fetal development. It helps in the regression of the Müllerian ducts, which would otherwise develop into female reproductive structures. Measuring AMH levels can be useful in assessing reproductive health in both genders.