Progesterone is made mainly by the ovaries. Each month, progesterone prepares your uterus for pregnancy. During a normal menstrual cycle, an ovary releases an egg and your progesterone levels begin to rise. If you don't become pregnant, your progesterone levels will fall. Your progesterone levels fall as you age, so low levels can be a sign that you’re peri-menopausal. If your progesterone levels are imbalanced, it can cause a wide range of symptoms like trouble getting pregnant, sleep disturbance, anxiety, hot flushes, breast tenderness, fibroids, PMS, water retention and migraines. If you have low progesterone level you have a higher chance of having osteoporosis, neurodegenerative diseases, hypertension and skin aging.