Norethindrone
CamilaPubChem CID 6230 · 3D model
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A lab-made version of progesterone that prevents pregnancy through several combined effects: thickening cervical mucus, suppressing ovulation in about half of users, and altering the uterine lining.
How it works
Norethindrone acts like the natural hormone progesterone in the body. According to its FDA label, it prevents pregnancy through several combined effects: it makes cervical mucus thicker so sperm have a harder time reaching an egg, it changes the lining of the uterus, and in about half of users it stops ovulation altogether. Because it doesn't contain estrogen, it works a bit differently than combination birth control pills, relying on this mix of effects together rather than blocking ovulation alone.
What it’s used for
Used as a daily birth control pill to prevent pregnancy. Unlike combination pills, every pill in the pack is active — there's no placebo week, and it must be taken at the same time each day to work reliably.
- Mechanism
- Synthetic progestin — progesterone receptor agonist
- Drug class
- Small molecule
- Therapeutic area
- Reproductive health / Contraception