Hi, Modus tablet contains progesterone hormone which is commonly prescribed to regularize the periods, stop irregular bleeding and to induce bleeding in case of amenorrhea (unusual stopping of menstrual periods). Its common side effects include headache, abdominal pain, weakness, and dizziness. It may also cause irregular periods, bleeding in between menstrual periods, depression, liver dysfunction, and weight gain. Take this medicine for as long as it is prescribed by your doctor however, if any of the above mentioned side effects bothers you, let your doctor know. There may be ways of reducing or preventing them Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Mohammed Taher Ali, General & Family Physician