The most serious adverse reactions associated with the use of estrogen are indicated under Warnings and Precautions. The following additional adverse reactions have been reported with estrogenic therapy. Genitourinary System: Breakthrough bleeding, spotting, change in menstrual flow, amenorrhea. Breasts: Tenderness, enlargement, secretion. Gastrointestinal: Nausea, vomiting, abdominal cramps, bloating, cholestatic jaundice. Skin: Chloasma or melasma which may persist when drug is discontinued, alopecia, rash. Eyes: Steepening of the corneal curvature; intolerance to contact lenses. Central Nervous System: Headache, migraine, dizziness; chorea. Miscellaneous: Increase or decrease in weight; edema; changes in libido, aggravation of porphyria. Common side effects include Headache, Breast pain, Irregular vaginal bleeding or spotting, stomach or abdominal cramps, bloating, Nausea and vomiting, Hair loss, Fluid retention, Vaginal yeast infection, Reactions from inserting Conjugated Estrogen Vaginal Cream, such as vaginal burning, irritation and itching.Uncommon side Effects Heart attack, Stroke, Blood clots, Dementia, Breast cancer, Cancer of the lining of the uterus (womb), Cancer of the ovary, High blood pressure, High blood sugar, Gallbladder disease, Enlargement of benign tumors of the uterus(fibroids), Severe allergic reaction.