Chapter 91:2
Non-Critical Illness on Shabbos
2. Any food or beverage that is generally eaten by healthy people
("ma'achal brie'im"), is permitted to be consumed for medicinal purposes
("refuah") on Shabbos; this applies even to items which have some negative
side effects on the body, in which case it would be obvious that the person
is consuming it as a cure (1).
However, any item which is not generally consumed by healthy people (2),
may not be consumed for medicinal purposes (3).
It is permissible to consume herbal juices, or drink a raw egg to make
one's voice more pleasant sounding (4). This is not considered medicinal,
since one's throat is not sore.
FOOTNOTES:
(1) As we saw in HY 91:1, the Sages prohibited all forms of medical remedy
("refuah") on Shabbos, because if people saw someone being treated
medically, they might think that even grinding up the herbs to make the
medication is permitted on Shabbos. Grinding ("Tochen") is one of the 39
categories of prohibited creative activity on Shabbos ("Melachos").
We see from today's halacha that the prohibition only applies to things
which are only consumed for medicinal purposes; however, items which are
consumed by healthy people, are defined as "food" not "medicine," and
therefore, are permitted on Shabbos, even in cases where it is clear that
the item is being consumed for medicinal purposes (See Mishna Berura 328:117).
(2) And therefore is defined as "medicine" not "food."
(3) This applies to someone who is only slightly ill, however, someone who
is experiencing pain over his entire body, or is ill enough to be
bedridden, even though the condition is not life-threatening, may take
medicine. Also, someone who is not sick at all, may consume an item that is
not generally consumed by healthy people, as long as he is not consuming it
solely to improve his health (See Mishna Berura 328:120). There is a
dispute among contemporary authorities as to whether a healthy person may
take vitamins on Shabbos.
