There are several forms of progesterone-based contraception, including progesterone-only pills (the “minipill”), the hormonal IUD (Mirena), and implants (Nexplanon and Implanon). All of these forms are halachically permissible, and all of them may cause irregular bleeding, especially during the first few months as your body adjusts to the hormones.
The implants are somewhat more likely to cause bleeding problems than the hormonal IUD, and it is more difficult to remove an implant than to stop taking pills or to remove an IUD. We recommend discussing the various options again with your physician – explaining the difficulties that irregular bleeding can cause in the context of taharat hamishpacha – before making a final decision.
You may take precautions against becoming niddah from any irregular staining caused by an implant, or any other form of hormonal contraception, by wearing colored underwear or disposable pantyliners and waiting at least a few seconds (ideally 15 seconds) after urinating before wiping. We also recommend abstaining from intercourse when experiencing staining until your status is fully clarified.
In the event that you experience an actual flow, you are rendered niddah. See here for a discussion of the difference between staining and a flow. There are leniencies that may help you complete the taharah process should staining cause difficulty, so feel free to get back to us for further guidance.
If there are prolonged bleeding issues with an implant that cannot be resolved with the above strategies, the only solution is to remove the implant.
Please feel free to get back to us with any further questions.
B’hatzlacha!
This response has been updated to reflect the rulings of our current Rabbinic Supervisor, Rav Kenneth Auman, regarding waiting before wiping.