Estrogen occurs naturally in both women and men. The word Estrogen is derived from the Greek word oistros (meaning "gadfly" but figuratively conveying sexual desire). Estrogen is a steroid hormone. Your sex drive is dependent on your androgen levels (which only exist in the presence of estrogen). All vertebrae, as well as some insects, synthesize estrogen. Estrogen enhances skin, blood circulation and blood vessel repair. Estrogen is produced by the ovaries in females. Peak estrogen levels occur just before ovulation. The liver, breasts and adrenal glands also produce small amounts of estrogen. These secondary sources of estrogen are essential in postmenopausal women. Estrogen increases bone strength. Women's Health Initiative (WHI) conducted a study that proved synthetic estrogen supplements were associated with an increased risk of blood clotting. *If taking a form of estrogen, always make sure it's a bioidentical version of your naturally produced estrogen hormone. Estrogen plays a significant role in woman's mental health. Estrogen has recently been used to treat bulimia nervosa patients after discovering that the disease may be linked to a hormone imbalance in the brain. Fat produces estrogen. this means that overweight people have higher-than-average estrogen levels, which causes imbalanced hormone symptoms. 80% of breast cancers need estrogen to grow. These cancers are known as hormone-sensitive or hormone-receptor-positive. A treatment for these types of cancers is the suppression of estrogen development. Recent studies have shown that common table mushrooms have anti-aromatase properties (a possible anti-estrogen effect). Scientists have begun to research whether or not table mushrooms can prevent breast cancer. Estrogen is occasionally used as treatment for men with prostate cancers. Estrogen promotes the development of female sexual characteristics (breasts, endometiral wall thickening, menstrual cycle, etc.). Estrogen is essential in men for the maturation of sperm and may be necessary for a healthy sex drive. Estrogen helps to accelerate metabolism. Estrogen has been used to help treat traumatic liver injuries. In the past, estrogen was used to prevent further growth in tall females. The 4 natural estrogens produced in women are: estrone (E1), estradiol (E2), estriol (E3) and estetrol (E4). Estradiol is the predominant estrogen in the body throughout a woman's reproductive years. Estrone is the predominant estrogen during menopause. Estriol is the predominant estrogen during pregnancy, trumping the potency of its sister estrogen, estetrol. Estetrol is only produced during pregnancy. Despite estriol being the most bountiful of the three estrogens, it's the weakest. Estradiol is the strongest estrogen (80x more potent than estriol).

30. http://denverhormonehealth.com/hormones/estrogen/