St. John's wort stops emergency contraception from working - Morning-after pill alert

You might need a Plan B if you’re taking the morning-after pill and using St. John’s wort.

The common supplement found in many herbal remedies to relieve depression, anxiety and inflammation could stop the hormonal emergency contraception Levonorgestrel from working, the Medicines and Healthcare products Regulation Agency (MHRA) warned in new guidelines released this week.

Levonorgestrel must be taken within three days (72 hours) of unprotected sex to prevent pregnancy. And now British scientists suggest that women taking St. John’s wort, a.k.a. Hypericum perforatum , should be given a double dose of the contraceptive to make sure it does the trick.

 

They also warned that certain ingredients in medicines used to treat epilepsy, tuberculosis, HIV and fungal infections can reduce the pill’s effectiveness. So women are advised to tell their doctor, nurse or pharmacist if they are taking meds to treat any of these conditions - or if they have in the last four weeks - before taking Levonorgestrel. You might get an extra shot of the contraceptive, or researchers also suggest asking health care providers about getting a copper intrauterine device, or “coil,” inserted into the womb, which will not interfere with any medications.