Antreol 1mg Tablet is used to treat early breast cancer in postmenopausal women and as a first line treatment for advanced breast cancer. It belongs to the aromatase inhibitors class and should be taken with or without food, at the same time every day. Common side effects include hot flushes, nausea, rashes, joint pain, osteoporosis, and weakness. Before taking Antreol, inform your doctor about any other medications, menstrual periods, liver or kidney problems, and if you are pregnant or breastfeeding. Blood tests may be performed to check vitamin D level or bone density.