Duphaston 10 is used to treat female infertility, various menstrual problems including painful, or irregular periods, Premenstrual syndrome (PMS) and endometriosis. It helps to restart periods that have stopped before the menopause and to prevent unusually heavy period. Duphaston 10 should be taken as your doctor advice. The dose and how often you take it depends on what you are taking it for. Your doctor will decide how much you need to improve your symptoms. Swallow the tablets whole with a drink of water. You should take this medicine for as long as it is prescribed for you. The most common side effects of this medicine include headache, nausea, and breast pain. It may also cause bleeding or spotting in between menstrual periods. Let your doctor know if this occurs frequently. If it bothers you, or appear serious, let your doctor know. There may be ways of reducing or preventing it. Before taking this medicine, tell your doctor if you are pregnant or breastfeeding, if you have ever had any problems with your blood circulation or have diabetes, depression or liver disease. Your doctor should also know about all other medicines you are taking as many of these may make this medicine less effective or change the way it works."