Estramustine phosphate (EMP), also known as estradiol normustine phosphate and sold under the brand names Emcyt and Estracyt, is a dual estrogen and chemotherapy medication which is used in the treatment of prostate cancer in men. It is taken multiple times a day by mouth or by injection into a vein. EMP was introduced for medical use in the early 1970s. It is available in the United States, Canada, the United Kingdom, other European countries, and elsewhere in the world.