Buy Ovral G Tablet General Information: This combination hormone medication is used to prevent pregnancy. It contains 2 hormones: a progestin and an estrogen. It works mainly by preventing the release of an egg (ovulation) during your menstrual cycle. It also makes vaginal fluid thicker to help prevent sperm from reaching an egg (fertilization) and changes the lining of the uterus (womb) to prevent attachment of a fertilized egg.