Peninei Halakha distinguishes between three categories of fast days. On minor fasts, anyone who is sick is exempt [1]. On Yom Kippur, only people whose lives may be in danger if they fast are exempt [1]. If you take medicine daily, Peninei Halakha writes you must continue taking it even on a fast day [1].
The three fast-day tiers and who is exempt
Peninei Halakha begins with the minor fasts, the ones instituted by the Rabbis rather than commanded in the Torah. These include the Fast of Gedaliah, the Tenth of Tevet, the Fast of Esther, and the Seventeenth of Tammuz. On these fasts, Peninei Halakha writes that anyone who is sick is exempt from fasting, even if the condition is not life-threatening [1]. The source defines sick broadly: people whose pain or weakness precludes them from continuing their regular routine of life, forcing them to lie down, are considered sick [1].
Tisha B'Av, the ninth day of Av, sits in a middle position. Peninei Halakha records the view that Tisha B'Av differs from the minor fasts, with only someone who is actually sick or liable to become sick because of the fast exempt, while even someone in great pain is exempt from the minor fasts [1]. The source also records that many poskim do not make such a distinction [1]. This means your rav may follow either approach depending on the community's custom and the specific situation.
Yom Kippur is categorically different because it is a Biblical command. Peninei Halakha writes that even the infirm are obligated to fast on Yom Kippur [1]. The only exemption is for people whose lives may be in danger if they fast, because the preservation of human life overrides the Torah's commandments [1]. Yom Kippur for 2026 begins at sundown on Sunday, September 20, and ends at nightfall on Monday, September 21 [2].
The distinction matters because it changes what question you bring to your rav. On a minor fast, the question is whether your condition causes you pain or weakness that stops your regular routine. On Yom Kippur, the question is whether fasting poses a danger to your life. These are not the same threshold.
What Peninei Halakha says about medicine on fast days
Peninei Halakha addresses the person who needs medicine regularly, such as someone with a chronic disease. The source writes that such a person must continue taking their medicine even on a fast day [1]. This is not optional; it is a requirement based on the principle that preservation of human life overrides the fasting commandment.
The source then gives practical guidance on how to take the medicine while respecting the fast. Peninei Halakha writes that if possible one should swallow the medicine without water [1]. The source notes that almost no medicine does any harm to those who take it without water [1]. This means that for many people, taking a pill dry is medically feasible.
For people who cannot swallow pills without water, Peninei Halakha offers a solution: add something bitter to the water until it becomes undrinkable and use it to swallow the pill [1]. The idea is that water so bitter it is no longer drinkable does not break the fast in the same way that regular water does. This is a compromise between the need to take medicine and the intent to fast.
Whether your specific medicine can be taken without water, and whether the bitter-water approach works for your situation, are medical questions for your clinician. Your clinician knows your exact medicine, your swallowing ability, and whether the medicine requires food or liquid to be absorbed properly. Bring the medicine bottle and the Peninei Halakha passage to that conversation.
How to prepare for a fast when you take daily medicine
The preparation starts weeks before the fast, not the morning of. Your first step is to talk with your clinician about your plan to fast and to ask specifically whether your medicine can be taken without water or with bitter water. Your clinician may say yes, may say no, or may say it depends on the specific formulation. Write down the answer and bring it to your rav.
Your second step is to talk with your rav about whether your condition qualifies you as sick under the fasting rules. Bring the Peninei Halakha passage and the definition from your community's tradition. If your rav says you are exempt from fasting, that settles the question and you take your medicine normally. If your rav says you are not exempt, or that the question depends on how you feel on the day itself, then you have a plan for taking medicine during the fast.
Your third step is to practice the method your clinician approved. If you are taking medicine without water, try it a few times before the fast so you know whether it works for you. If you are using bitter water, prepare it ahead of time so you know what it tastes like and whether you can manage it. Do not try a new method for the first time on the fast day itself.
Your fourth step is to write down your medicine list and your clinician's guidance and bring it with you. If you are fasting away from home, or if someone else is caring for you during the fast, they need to know what medicine you take and how you take it. A written list prevents confusion and keeps you safe.
For the broader picture of preparing for a fast with a chronic condition, see the preparing for a fast with a chronic condition guide. The Yom Kippur medication guide covers the specific rules and questions for that fast. The guides hub collects all the fasting and medication resources in one place.
The difference between fasting and taking medicine
A fast means not eating and not drinking. Taking medicine is not eating and not drinking; it is taking medicine. Peninei Halakha makes this distinction clear by writing that sick people must continue taking their medicine even on a fast day [1]. The source does not say they may take medicine or that they should consider taking medicine; it says they must.
This does not mean the fast is broken or that you are not fasting. It means that the commandment to fast is overridden by the commandment to preserve your health. The two commandments exist together. You are fasting in the sense that you are not eating or drinking for pleasure or nourishment; you are taking medicine in the sense that you are taking medicine because you need it to stay well.
The bitter-water approach illustrates this principle. The water is bitter enough that it is no longer drinkable, which means it is not a drink in the ordinary sense. You are using it as a vehicle for medicine, not as a beverage. This preserves the spirit of the fast while allowing you to take medicine safely.
Your rav may have a different interpretation or a different custom in your community. The question to bring is not whether you should take medicine, but how to take it in a way that respects both your health and the fast.
Fast-day tiers and medicine rules
Here is how Peninei Halakha describes the three fast-day categories and what each source writes about medicine.
| Fast type | Who is exempt | What to ask your rav |
|---|---|---|
| Minor fasts (Fast of Gedaliah, Tenth of Tevet, Fast of Esther, Seventeenth of Tammuz) | Anyone who is sick, even if the condition is not life-threatening, including people whose pain or weakness forces them to lie down [1] | Whether your condition qualifies as sick under this definition, and if not exempt, how to take your medicine on the fast |
| Tisha B'Av | Peninei Halakha records the view that only someone actually sick or at risk of becoming sick is exempt, though many poskim do not make that distinction [1] | Whether your community follows the stricter view or the broader exemption, and if you are not exempt, how to take your medicine |
| Yom Kippur | Only people whose lives may be in danger if they fast, because preservation of human life overrides the Torah's commandments [1] | Whether fasting poses danger to your life given your condition and medicine, and if you are not exempt, how to take your medicine without breaking the fast |
What to do next
- Print the Peninei Halakha passage on fasting and medicine and read the section on the infirm and on medicine.
- Call your clinician and ask whether your medicine can be taken without water, with bitter water, or whether it requires regular water or food to work properly. Write down the answer.
- Ask your clinician whether fasting poses any medical risk for you given your condition and your medicine list. If the answer is yes, bring that to your rav.
- Bring the Peninei Halakha passage and your clinician's answers to your rav and ask whether your condition qualifies you as sick under the fasting rules for the specific fast you are planning.
- If your rav says you are not exempt, ask which method your rav recommends: taking medicine without water, or using bitter water. Practice the method before the fast.
- Write down your medicine list, your clinician's guidance, and your rav's ruling and keep it with you during the fast.
- If you are fasting away from home or someone else is caring for you, share the written information with them before the fast begins.
Sources
- Peninei Halakha, the infirm are exempt from fasting, accessed 2026-08-09, https://ph.yhb.org.il/en/05-07-07/
- Hebcal, Yom Kippur 2026, accessed 2026-08-09, https://www.hebcal.com/holidays/yom-kippur-2026