Estrogen is a hormone that is made from DHEA (dihydroepiandosterone) and is found in both males and females. In females, its primary function is to regulate the monthly menstrual cycle but it also has other effects. This hormone is very important in strengthening the bone structure of the body. It causes decreased osteoclastic activity and causes deposition of calcium ions. It also joins the epiphyses of the bones and hence causes the women to be of shorter than that of men. The skin becomes more vascular and the number of red blood cells also increases. Its production decreases as aging occurs and it reaches an all time low at the age of 45 approximately (also known as menopause). Menopausal women are administered in order to make up for the lack of it. In males, estrogen is produced in a considerably lesser amount then those of women in order to help in process of spermatogenesis (formation of sperms) and hence plays a significant role. Estrogen is a very important hormone and its imbalance can have severe consequences hence people who have issues of lesser quantities than the normal values should take exogenous forms of it.