Norimin is a type of combined hormonal contraceptive (CHC) known as ‘the pill’, or the combined oral contraceptive pill (COCP). It contains two active ingredients which are synthetic (man-made) forms of naturally occurring female sex hormones. These are ethinyl estradiol (a synthetic form of oestrogen) and norethisterone (a synthetic form of progesterone). CHCs such as Norimin prevent the release of an egg from the ovary (ovulation). They change the mucus in the cervix (entrance to the womb) and the lining in the womb which helps make it difficult for sperm to reach an egg, or for an egg to embed itself in the womb lining.