Along with progesterone, estrogen an important sex hormone in women’s bodies. It is responsible for reproduction and typical physical features in females, such as public hair and breasts. More importantly, the substance contributes to essential bodily processes, cardiovascular function, bone health, and cognitive health. Fat tissues, adrenal glands, and ovaries produce estrogen. Though both male and female bodies have estrogen, it is released more in women. In premenopausal individuals, levels of progesterone and estrogen can vary between each menstrual cycle.