It is important to distinguish between uterine bleeding, which makes a woman niddah, and bleeding from outside the uterus, which does not.

Some medications may lead to breakthrough bleeding, uterine in origin, which can make a woman niddah. A woman’s status in such cases would depend on the nature of the bleeding. For example, a flow of blood, comparable to a period, would make her niddah. However, breakthrough bleeding often presents as staining, in which case many halachic leniencies apply. Please see our pages on stains and toilet paper for more information.

Sometimes medications may lead to increased chances of local irritation, leading to bleeding from the outside of the cervix or the vaginal wall. When bleeding is identified as resulting from such irritation, it does not make a woman niddah. If that is the concern, you should still use the knowledge gained from reading about the laws of staining to minimize halachic questions. But if a question does arise information from your physician or, in some cases, a medical examination, may confirm that you have an irritation and enable you to remain tehorah (not in niddah).

We recommend that you begin by consulting your doctor to find out whether uterine bleeding is likely on your current medication and what other type of bleeding or irritation might be expected. Then please be in touch with any follow up questions.

To minimize questions, we recommend being especially careful to wear colored underwear (except during the shivah neki’im), and waiting at least a few seconds (ideally, about fifteen seconds) between urinating and wiping with toilet paper. Relations should take place on a colored sheet and/or towel, and any wiping afterwards should be done either with a colored cloth or with toilet paper that is discarded without being looked at. Please see here for more details about precautions.

We wish you hatzlacha with the treatment. You may also find it helpful to arrange a free consultation with a Yoetzet Halacha Fertility Counselor, details here.

This response was updated on 4 February, 2024.