Although the Women s Health initiative did not take in hand this particular query, observational undertakings proved that taking estrogen for quite a while starting in menopausal stage prove to have some health benefits. Among these benefits are: Lower hip fractures Lower cases of heart attacks While the negative effect for long-term intakes over dosage are: Gall stone Breast cancer Endometrial cancer The bottom line is, too much of something is bad for one s well being, even if we talking about a compound with an immense health benefit and wonders- as in the case of estrogen. Estriol - this is the least powerful among the three. Since these estrogen hormones can be taken, they have the same effects and side effects especially if the doses are the same. The hormones should not be used when a woman is pregnant because it can lead to miscarriage. If taken at the earlier stage of pregnancy, it can badly harm the developing fetus. At such period, oestrogen support the development of secondary female sex features, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual series. Sources of oestrogen include the ovaries, the corpus luteum, and the placenta. Smaller amounts of it are found in the liver, adrenal glands, and breasts. It gives the identifying figures of women, which are smaller hips, bigger chest as well as menstruation. Estrogen is also essential to normal body function, which is why women should maintain normal estrogen level in the body. Old age can be one of the reasons why women experience irregular estrogen production. Since Estrogen therapy has the long term and the short term period, it must be noted that lower dose of medicine should be taken for the long term in order to reduce the risk. It is also necessary that you see your doctor at least twice a year while you are taking the medication to avoid complications. In addition, researches have also shown that there is a greater risk of breast cancer among women who use both the estrogen and the progestin. Other possible negative effects of estrogen include: Vaginal bleeding or spotting Abdominal pains Poor sleeping habit Skin rashes Depression Head aches, migraine headaches Causes endometrial cancer Therefore, with both of these positive and negative effects presented, the decision in taking estrogen will not be all yes .