This study is investigating a new medication being developed (known as Endoxifen), to reduce the risk of getting breast cancer and reduce the risk of developing reoccurring breast cancer after Estrogen Receptor (ER)-positive breast cancer has been treated. Endoxifen, is a metabolite or by-product the body produces after the drug Tamoxifen is taken (Endoxifen is produced when Tamoxifen is broken down by the body). Tamoxifen has been widely used around the world for over 30 years. Previous clinical studies have shown that Endoxifen is important to the effectiveness of Tamoxifen.
This study is for healthy females only.