Progestin
Norethindrone with the birth control pill
Many women of reproductive age take a combined or progestogen-only oral contraceptive while also using a chronic medication such as Norethindrone (Norethindrone). The combination is generally fine at 5mg, but a small number of medications can reduce contraceptive efficacy meaningfully and need either a backup method or a switch.
How Norethindrone can affect contraceptive efficacy
Combined and progestogen-only contraceptives are metabolised through CYP3A4. Strong CYP3A4 inducers (some antiepileptics, rifampicin, St John's Wort) lower contraceptive plasma levels and reduce efficacy. Whether Norethindrone acts on CYP3A4 determines whether Norethindrone affects contraception. Most agents in Progestin have no clinically meaningful effect on the pill at 5mg.
Practical guidance
According to the prescribing information for Norethindrone, women on hormonal contraception should review Norethindrone with the prescribing pharmacist or doctor. Where an interaction is documented, additional barrier contraception or switching to a non-oral method (IUD, implant) for the duration of Norethindrone therapy is the standard mitigation.
Frequently asked questions
Will Norethindrone make my pill less effective? ▾
Most Progestin medications at 5mg do not affect oral contraceptive efficacy. The exceptions are CYP3A4-inducing drugs and a small number of others. The prescribing information for Norethindrone states whether the interaction is meaningful.
Do I need a backup contraceptive on Norethindrone? ▾
Backup contraception is needed only when there is a documented interaction between Norethindrone and the contraceptive method. For most users at 5mg, no backup is required. The pharmacist confirms whether Norethindrone interacts with hormonal contraception.
Products containing Norethindrone
More on Norethindrone
- With alcoholNorethindrone and alcohol — is it safe to drink?
- With foodShould Norethindrone be taken with food?
- Side effectsNorethindrone side effects: common, rare and warning signs
- Dosage guideNorethindrone dosage guide: how much to take and when
- OnsetHow fast does Norethindrone start working?
- DurationHow long does Norethindrone last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.