The uses of Norinyl-1 include: Norinyl-1 is a birth control pill commonly known as a "Combined Oral Contraceptive", that contains both an oestrogen (mestranol) and progestogen (norethisterone) hormone. Sometimes Norinyl-1 is used to help control heavy, irregular or painful periods.
Oral contraceptives belonging to this group produce their birth control (or contraceptive) effect by preventing ovulation (or the release of an egg from the ovary) during each menstrual cycle. Combined Oral Contraceptives also cause changes to the mucus of the cervix and the lining of the womb which contribute to the contraceptive action.
If taken according to directions the combined oral contraceptives are very effective in preventing pregnancy. The failure rate of this type of contraceptive is such that for every 1,000 women using the pill for one year, two will become pregnant.