Hi, Cerazette contains desogestrel which is used in the treatment of various menstrual problems like irregular periods, painful or heavy bleeding during periods, endometriosis, reduce the risks of developing ovarian cysts etc. It contains progesterone only, a female natural hormone called desogestrel is also used to prevent unwanted pregnancies from unprotected sexual activities. It is a safe and effective medication for long term use if it is taken in doses and duration as advised by your doctor. But, like other medications, it has some side effects like irregular uterine bleeding, breakthrough bleeding or spotting between periods, migraines like headache, sweating, mood swings, depression, acnes, facial hair growth, breast tenderness and enlargement, vaginal discharge, vaginal bleeding, changes in body weight, allergic reactions etc. These side effects are mild and self limiting as well as go away eventually as your body adjusts to this medication. You should follow your doctor s advice and take the medication that is advised by your doctor. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Zubayer Alam, General And Family Physician