Non-alcoholic fatty liver disease (NAFLD) is a growing epidemic in the United States. Despite this, the treatment options remain limited. Preclinical and preliminary clinical data suggest that estrogen deficiency plays an important role in the pathology of steatosis, inflammation and fibrosis in non-alcoholic steatohepatitis (NASH), the progressive form of NAFLD. Post-menopausal women are a growing population with particularly high risk of NASH due to their lack of estrogen. This study will examine the effect of estradiol on hepatic fibrosis and fat in post-menopausal women with NASH.