NORIDAY is an oral contraceptive pill that belongs to a group of medications known as progestogen-only pills (POPs), or mini-pills. It contains the active ingredient norethisterone, which is a synthetic form of the naturally occurring female sex hormone, progesterone. Unlike combined oral contraceptives that contain both estrogen and progestogen, NORIDAY works primarily by thickening the cervical mucus to prevent sperm from reaching an egg, and by altering the lining of the uterus to prevent implantation of a fertilized egg. It is particularly suited for women who are sensitive to estrogen or are breastfeeding, as it does not contain estrogen. NORIDAY is taken daily without a break, and it is essential to take it at the same time every day for it to be effective in preventing pregnancy.