(Concerning whether you are allowed to take medication on Shabbat for your own specific situation, consult an orthodox rabbi.)

The sages prohibited taking medication on Shabbat – except in specific situations – out of concern that one may grind the herbs to make the remedy, which would be a transgression of the Torah prohibition of grinding (tochein) on Shabbat. Nowadays, most people don’t construct their own remedies; nevertheless, the consensus of contemporary poskim is that we cannot undo a rabbinic prohibition even if the reason is no longer applicable1 (especially if some do still compound homemade remedies).2

It is self-understood that whenever there is even a slight possibility of a life-threatening situation (safek pikuach nefesh), it is permissible to transgress melachot as needed. In addition, one who takes medicine daily which preempts a life-threatening situation may continue to take it on Shabbat, even if skipping one dose would not result in a life-threatening situation.

Additionally, one may take medication on Shabbat to remove an infection—but only if by not treating the infection it could lead to a life-threatening situation.3

However, in the absence of any danger, there are three general categories:4

1. Michush kal: A mild malady (such as a minor cold5 or a cough6). In such a case, a person may not transgress any prohibition.7

2. Tzaar gadol: One who is in significant pain, but is not weak or incapacitated. Such a person may transgress a rabbinic prohibition but must do so in an unconventional manner (such as mixing the medicine with one’s food, as long as this mixture was prepared before Shabbat).8 However, in the category of tzaar gadol one may not take medication or undergo treatment (except external treatment applied by a non-Jew).9 This precludes Tylenol for manageable pain, powder for a rash, Tums for heartburn or sucking lozenges for a sore throat.10 Some hold that one who is on a schedule of medicine for such an ailment may continue taking the dosage on Shabbat.11

3. Choleh she’ein bo sakana: One who is in severe pain and cannot function (e.g., migraine headache) may do a melachah in an unusual manner, ask a non-Jew to perform a melacha in the normal manner, and take medication.12 Medication may be taken as soon as the pain begins, even if it is bearable at that time.13

Some poskim write that if the medication is thoroughly mixed before Shabbat into a food that is not normally taken with medicine, one may eat that food on Shabbat. This is because (a) he has actively distinguished it from normal medication – and therefore won’t think to prepare medication on Shabbat, and (b) it looks different – so others won't think medication is permissible. This is the optimal solution for one who may experience heartburn or headaches on Shabbat.14

This article has been generously provided to Chabad.org by Merkaz Anash.