Pregnancy can be prevented by oral contraceptive pills which alter the menstrual cycle in order to inhibit ovulation. There are several options of birth control using contraceptive pills throughout the world. Two contraceptive pills, Velivet & Camila are described in this assignment. In case of Velivet, it is a combination of ethinyl estradiol & desogestrel which inhibit ovulation. It prevents pregnancy by suppressing FSH & LH which eventually alter secretion & cellular structure of endometrial linings that ultimately prevents implantation. On the other hand, Camila prevents sperm from reaching to the egg and ultimately prevents fertilized egg attaching with lining of uterus by making the vaginal fluid thicker. However, these two pills have unwanted effects. They are not effective against sexually transmitted diseases such as HIV, gonorrhea, chlamydia. Moreover, weight gain, vaginal bleeding, headache, irregular periods may occur when these pills are administered. These contraceptive pills should be administered according to the instructions of gynaecologist.