Overview

The minipill norethindrone is an oral contraceptive that contains the hormone progestin. Unlike combination birth control pills, the minipill — also known as the progestin-only pill — doesn't contain estrogen. The progestin dose in a minipill is lower than the progestin dose in a combination birth control pill.

The minipill thickens cervical mucus and thins the lining of the uterus (endometrium) — preventing sperm from reaching the egg. The minipill also suppresses ovulation, but not consistently. For maximum effectiveness, you must take the minipill at the same time every day.