Medicine From Oyster Shell

I bought a prostrate relief dietary supplement and I see it contains calcium derived from oyster shell powder. Am I allowed to take it?

The Aish Rabbi Replies:

Yes, it is permissible and we wish you a speedy recovery.

In greater detail, in general the Torah forbade only edible parts of non-kosher animals – not the claws, horns, shells etc. The reason is that such animal parts are completely inedible and not considered “food” at all. (See Leviticus 11:8 which only forbids the flesh of non-kosher animals (see Rashi there citing Sifra 4:8).) Note, however, that many types of bones and shells – in particular of shellfish – do impart some taste and are forbidden. Also, the “sinew of the thigh” (gid ha’nasheh) is one exception to this rule, and is explicitly forbidden by the Torah even though it has no taste.

Even so, there is still a potential issue. When an inedible shell is made into an edible product, we preferably should not eat it. Although technically not forbidden, it still is

See also this response for a more detailed summary of the laws of non-kosher medicines.

(Sources: Sefer HaChinuch 74; Mishnah L’Melech, Yesodei HaTorah 5:8; K’sav Sofer O.C. 111; Achiezer Y.D. 11; Tzitz Eliezer X 25:20; Minchas Yitzchak IX 79.)

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