In regard to the prohibition of taking medicine on Shabbos they bring from the Shevet HaLevi (Kovetz MiBeis HaLevi vol. 13, pg. 52, siman 14) and from R’ Elyashiv (Hilchos Bein HaMetzorim) that if the medicine is mixed into food or drink, one may take it on Shabbos, as it is not considered a medicine, but is rather considered a food. However, one should make sure to mix it before Shabbos, as if one mixes it on Shabbos with water and sugar then the act of mixing is considered hachonah on Shabbos for the weekday.
However, the Igros Moshe (Orach Chaim, Vol. 2, siman 86) discusses mixing medicine with food and he quotes the Shulchan Aruch (328:21) which says:דשורה אדם קילורין בערב שבת ונותן ע''ג העין בשבת שאינו נראה אלא כרוחץ והוא דלא עמיץ ופתח ולא חיישינן משום שחיקת סממנים דכיון שלא התירו לו לשרותן אלא מערב שבת איכא הכירא – “A person may prepare eye ointment (a special type used for heeling the eyes) on erev Shabbos and put it on his eyes on Shabbos, as it just looks like one is washing himself. However, one must make sure not to open and close his eyes when putting it in. We are not worried about the gezeirah of grinding spices, as the heter is only when one prepares the ointment on erev Shabbos, therefore, it is recognizable.” The Mishnah Berurah (s.k. 69) explains: Even though one knows that it is being done for healing purposes, nonetheless, it is allowed, since there is a heker as one must prepare and start soaking it before Shabbos, and not on Shabbos itself just before use.
Based on the above, the Igros Moshe rules that if one is not a choleh she’ein boi sakonah [sick but not in danger], and it is forbidden for him to take medicine on Shabbos, if generally speaking the medicine is placed inside food or a drink when taking the medicine, then one may mix it into food or drink before Shabbos and take it on Shabbos, as the mixing into food or drink before Shabbos serves as a heker not to do refuah on Shabbos. However, if one is taking a medicine that is not normal to mix, then even if one mixes it before Shabbos there is not enough of a heker by mixing it before Shabbos, and even if it was mixed it shouldn’t be taken on Shabbos.
The Igros Moshe further adds: Since the way to use this special eye ointment is to start soaking it before Shabbos, when soaking it already on erev Shabbos it’s like one has already started putting it into his eyes before Shabbos, since the start of the treatment is to soak it on erev Shabbos. However, this only helps if the medicine is the type of medicine that needs to be soaked/mixed into food or drink, if it is such a medicine then mixing it into food or drink before Shabbos would be considered starting the medicine before Shabbos and mixing it into food or drink before Shabbos would be a heter to take it on Shabbos. If, however, the medicine is not the type that needs to be mixed into food or drink, then doing so before Shabbos doesn’t make it considered like one has already started taking it before Shabbos, and it won’t make it permissible to take on Shabbos.
The Shevet HaLevi Is More Lenient
However, the Shu”t Shevet HaLevi (3:36 and 8:82) is lenient even if the medicine doesn’t need mixing with food and drink. He explains that the heter of mixing with food is not based on bitul berov [nullification in a majority], rather, the heter is that when there is a mixture of food and medicine, since the food is main part of the mixture, we look at it as food and Chazal never made a gezeirah against eating food on Shabbos. According to this, even if the medicine doesn’t need to be mixed with food, if one does mix it with food and the food is considered the main part of the mixture, then there is no gezeirah and it may be taken on Shabbos.
The Maharsham
The Da’as Torah (Maharsham, 328:37) brings this heter from a Shita Mekubetzes in Berachos (38a). However, the Maharsham says clearly that the entire heter is when mixing two foods, where each food is considered machol beriyim, however, it is not normal to mix the two together. If, however, one of the foods is not considered machol beriyim, then it would be forbidden, even if the main component is a food which is considered machol beriyim. According to this, mixing medicine into food, even if the food is the main component wouldn’t help.
The Opinion of the Minchas Yitzchok
The Shu”t Minchas Yitzchok (6:28) also discusses mixing medicine into food and drink before Shabbos, and he points out that according to the Maharsham seemingly it wouldn’t help. However, he writes that the She’orim Metzuyonim B’Halachah (91:2) quotes the Shu”t Mishpetai Tzedokah (siman 40) who is lenient and holds that since the medicine is mixed in with food there is a heker, and there is no longer a gezeirah of shechikas samamonim [grounding spices]. Just like we find that pas akum [bread baked by a non-Jew] is permissible if a Yid throws in a chip of wood into the fire, as there is a heker, so too by medicine, if it is mixed into food there is a heker and is therefore permissible on Shabbos. The Minchas Yitzchok concludes, that if the medicine is mixed before Shabbos, if one is in pain, he has what to rely on.
The Opinion of R’ Shlomah Zalman Auerbach
R' Shlomah Zalman Auerbach (Shulchan Shlomah, 328:36) is also lenient with the above, although he adds that it only helps if the medicine is crushed before Shabbos and mixed into the food or drink in way that it is no longer recognizable, however, simply putting it inside food or drink in its complete form and covering it doesn’t help. The reason being: If the medicine is still recognizable then it would still be forbidden like we find maras ayin is forbidden even in private, therefore, to make it permissible it must be crushed.
In light of all the above, it would seem that if one mixes the Kalei-Tzom supplement into a cup of water before Shabbos and it is dissolves, then everyone would agree that if one has a great need, he may take it. If, however, one mixed it into food or drink and it remains complete, according to R’ Shlomah Zalman it is still a problem, and in such a case the solution would be to swallow it after Shabbos on Tisha B’Av, and if one needs some water to help it go down, he should make the water bitter, in order not to enjoy it.
The Sign the Chofetz Chaim Would Hang Up in Radin Before Tisha B’Av
Every year before Tisha B’Av the Chofetz Chaim would hang up a sign in his Yeshivah in Radin informing people of an eitzah [solution] to help make the fast easier. The sign would say: Drink a cup of very sweet tea, and then drink a second cup of tea without any sugar at all (cited in Derech Sicha, pg. 381).
