It maintains the normal function of the endometrium It relaxes the myometrium. It is the hormone used to prevent the uterus from contracting during pregnancy. It serves as the precursor for the critical fetal hormones during pregnancy. It is also responsible for the stimulation of the aldosterone to produce more during pregnancy. The most common side effects with estrogen hormone are: Softness of the breast, either men or women Inflammation of the ankles and legs Lesser cravings for food Sudden changes in weight Nausea Vomiting Abdominal pains Skin Irritation Other side effects are: Bleeding gums Vaginal bleeding and spotting Changes in menstrual flow Painful menstruation PMS or the pre-menstrual syndrome Vaginal infection such as Candida Diarrhea Loss of scalp hair Migraine Faintness Despair Increased sexual desires Decreased sexual desires Rare side effects include: Blood clotting Sudden feeling to urinate Unclear speech Changes in vision Breathlessness Estrogen hormone should always be balanced. Some of the patients can be prone to more side effects especially if Estrogen patches are not suited for them. Most common side effects of Estrogen patches are skin irritation, back pain and sometimes headache. Sometimes you will also experience bloating and abdominal cramps but these are very rare side effects. However, in some cases there are still some of them who gives birth to the so-called menopausal babies. While a woman is entering the menopausal period the level of Estrogen is affected. This is a kind of hormone that plays a very important role in the female reproductive system. Thus, if the level of this hormone reduces there is a tendency that a woman will suffer from various disorders. 3. It can be very dangerous for women who are more prone to blood clotting. 4. It can give headaches or migraines 5. It increases the threat for endometrial cancer 6. It can destroy the liver With all these advantages and disadvantages presented, it all depends to the person if she wants to have the therapy. For an unknown reason, estrogen helps women against cardiovascular diseases from her childhood up to middle age. Therefore, when there is an insufficient estrogen in a woman s body, she is susceptible to any cardiovascular diseases. In order to prevent this, hormone replacement therapy must be made. However, the therapy is only good for women who has estrogen deficiency and wants to prevent her self from having a cardiovascular disease.