Oral contraceptives, usually in the form of a pill or an injection, is a type of chemical birth control. They usually contain sex hormones, mainly progesterone and estrogen that disrupts the menstrual cycle and stops eggs being produced in the ovaries by inhibiting the production of FSH. This method helps in controlling the size of a family , allowing couples to choose the time they start a family or the time they stop having children. However, some women who take these pills may experience changes in weight, mood and blood pressure. There is also a chance of an increased risk of developing blood clots.