High progesterone levels can be caused by a variety of factors, including pregnancy, hormone replacement therapy, the oral contraceptive pill, and progesterone supplements. High levels of progesterone are not typically associated with negative health effects. However, high levels of progesterone can cause symptoms such as weight fluctuations, fatigue, bloating, discomfort or pain in the legs, water retention, and changes to sex drive/libido. High levels of progesterone are a consequence of an inherited condition known as congenital adrenal hyperplasia. Lifestyle factors such as smoking and consuming commercial cows milk can also cause elevated progesterone levels.