797. Healthy People Not Taking Medicine
Shabbos 21:20
One who needs to crush pepper and other spices to season food on Shabbos may crush them against their bowl using the handle of a knife. One may not use a pestle because that would be grinding. This is why a healthy person may not take medicine on Shabbos: it is a preventive measure to keep one from grinding the necessary ingredients.
Shabbos 21:21
Since a healthy person may not take medicine on Shabbos, one may not eat foods that are not normally eaten by healthy people, like hyssop, nor herbs that loosen one’s bowels, like wormwood. One may likewise not drink beverages that are not ordinarily drunk by healthy people, like water that has been cooked with herbs and grasses.