Hi, Femiplan Pill contains both estrogen and progesterone that is used in the prevention of unwanted pregnancies from unprotected sexual intercourses. It is also used to various menstrual problems like irregular periods, heavy bleeding during periods, painful menstrual cycles, pre menstrual syndrome or PMS, ovarian cysts, endometriosis, acnes etc. Like other medications, this medication has its side effects too. Though it is rare but it may cause weight gain. It is possible to do gain a little bit of weight immediately after starting birth control pills like Femiplan. This may result from water retention, not extra fat. This changes in body weight is usually temporary. This water will go away eventually on its own, over time and increased body weight due to water retention will come back to normal. But, this weight gain persists for long or bother you, then you should inform your doctor first for medical attention. 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,