Estrogen is a mitogenic hormone which means it stimulates the replication and reproduction of cells. This is a good thing in pregnant women but for the rest of us, wildly replicating cells is dangerous to our health, and it sets the stage for the growth of cancerous tumors. Many people think of estrogen as a female hormone, and although it does play a more dominant role in women’s bodies, men are affected by it too. An estrogen deficiency can cause muscle and bone loss, weight gain, increased heart disease risk, lowered libido and fertility issues in both males and females alike. Too much estrogen (a condition referred to as estrogen dominance) is much more common than too little however, and it can cause a range of undesirable symptoms including hair loss, weight gain, infertility, loss of libido, anxiety, fatigue, PMS, fibroids, autoimmune disorder and certain types of cancer.