Progesterone Replacement can help many symptoms. Once a woman hits her mid to late 30’s she can enter perimenopause, and progesterone production starts to decline. Once she reaches menopause, circulating progesterone levels are so low, they are similar to levels normally seen in men. Research shows that adding back the progesterone can improve brain function, mood as well as cardiovascular, and nervous system health. Progesterone can protect against uterine and breast cancer, helps fat metabolism, normalize blood sugar, reverse osteoporosis, improve thyroid function and act as a natural antidepressant, and reduce anxiety.