If a medicine is not palatable, it is not a food. If it is not a food, you don't use the brachos that are for food when you take it. If the medicine is palatable, it is a food, and you make a bracha on it (although that bracha might be she'hakol; see OC 204:8 and Aruch Hashulchan 204:22. Also, See Rabbi Bodner's ותן ברכה chapter 13:15.1, quoting RS'Z Auerbach's solitary opinion that if you would not eat it as a food, then you do not make a bracha even if it has a good taste.) That is not what this post is about. I want to discuss the bracha one would make for the therapeutic quality of the medicine.
Based on the Gemara in Brachos 60a, the Mechaber (OC 230:4) says that when one begins a blood letting, a process once thought to be salubrious, one should say יהי רצון מלפניך ה' אלוקי שיהיה עסק זה לי לרפואה כי רופא חנם אתה. After the process is finished he should say בָּרוּךְ רוֹפֵא חוֹלִים. The Mishna Berura (SK 6) and the Aruch Hashulchan (5) say that this applies to all medical procedures, and whenever one takes a medicine or engages in a medical procedure he should say these words with Hashem's name. (We are not noheg to use Hashem's name in the bracha after the procedure, but we certainly ought to say יהי רצון מלפניך ה' אלוקי, considering we are going to say that when we eat the simanim Rosh Hashannah night. Taking medicine is far far more serious.)
During my shiur, one of the talmidim asked a good question. The Gemara in Brachos 35a says that Chazal instituted formal brachos on foods because of the compelling logic that we ought to thank Hashem when we benefit from His world. סברא הוא אסור לו לאדם שיהנה מן העולם הזה בלא ברכה -it would be a sin to benefit from Hashem's world without blessing Him. If so, why shouldn't we make a bracha when we take medicine? Are we not benefiting from Hashem's world? Are we not grateful that the medicine cures us or alleviates our pain? It would seem that the logic that instructs us to express our gratitude for the nourishment we get from food would compel us to make a bracha on the therapeutic benefit we get from a medicine.
One might propose an answer that the bracha on food is primarily for the pleasure we have from eating, not for the nutrition of the foods. If so, we would only make a bracha on medicine if we enjoy the administration of the medicine. I disagree. (Please note that this is indeed a machlokes Achronim insofar as what Birkas Hamazon is on, the enjoyment or the nutrition. In fact, this was the topic of my Bar Mitzva Drasha in 1965. But I do not believe that the logic of the din derabanan of bracha rishona is necessarily the same as the logic of the din deoraysa of bracha achrona.) While it's true that we make a bracha only on palatable foods, not on nutrients that we don't enjoy ingesting, or on intravenous nutrition, the primary purpose of the bracha is to express our gratitude and acknowledgment to Hashem for sustaining us. It's like the mitzva of Sukkah: we are chayav to live there, but Chazal were kovei'a the bracha on eating because when you eat you focus your attention on the enjoyment and circumstances of your meal. If we didn't eat in a Sukkah, Chazal would have been kovei'a a bracha on sleeping, or reading the newspaper, or sitting and shmuzing in the Sukkah. Since we do eat there, they chose eating as the best moment to make the bracha. But the ikkar is the Taduru, and here the ikkar is the nutrition. Since by medicine you never enjoy taking it, Chazal should have been kovei'a a bracha on all medicines.
The Magen Avraham (OC 216 SK 1) brings that one only makes a bracha on palpable physical enjoyment, and this is why we don't make a bracha upon hearing a beautiful voice, or a massage, or the heat of a fire. That is all fine, but it doesn't explain why we wouldn't make a bracha when we take a medicine. It's palpable and it directly affects the body exactly like food.
The answer to his question is that while both food and medicine are beneficial, there is a fundamental difference between them: Food nourishes us and contributes to the body's regeneration and growth. Medicine is מבריח ארי, it eliminates a problem. Medicine eliminates an infection, is cures a malady, it alleviates pain. It is, in a sense, Rashi's מלאכה שאינה צריכה לגופה, something that you have to do to remove a problem, not something that you do because you want a positive benefit. The Svara of Bracha applies to enjoyment/benefit that is absolute, not the enjoyment/benefit you have when something stops hurting you. (see, e.g., Rama in OC 204:8, but see also the Mechaber in 204:9, and how the Aruch Hashulchan resolves them in 204:19. This is not an exact match: it is just a tzushtell. Look inside and you'll see what I mean.)
Although we certainly do make brachos on being saved from mortal danger, namely הטוב והמטיב and שעשה לי נס במקום הזה, those are brachos of שבח והודאה, not ברכת הנהנין. The logic of ברכת הנהנין is totally different than the logic of ברכות שבח והודאה. A proof of this distinction is the shitta of Rav Yehuda in the Mishna on 40b who says that we don't make any bracha on a food that comes from a klala, such as locusts: כל שהוא מין קללה אין מברכין עליו. Does Rav Yehuda disagree with the brachos of הטוב והמטיב and שעשה לי נס? No, he does not. It must be, then, that the logic of ברכת הנהנין is different than the logic of ברכות שבח והודאה.
Someone then pointed out that this would only explain why we don't make a bracha on the most common medicines. But what about psychoactive drugs, such as caffeine, or marijuana (ingested, not smoked), or psilocybin mushrooms or LSD or medicines that until Bob Dole were considered unmentionable? The benefit from these medicines is a positive, not merely the elimination of a negative. (We are discussing drugs that are not injurious to the body or the mind.)
I suppose that the answer is that Chazal didn't want to create a bracha for any medicine or drug because the vast majority of drugs fall into the first category rather than the second. (Similarly, it would seem that intravenous administration of nutrition would have exactly the same halacha as food and require a bracha. But since most intravenous procedures are to administer medication, and when food is given in this manner it is because of some very serious malady, no bracha is said.)
Still, it would seem to me that even though Chazal did not create a nusach of a bracha for these drugs, the Svara, the compelling logic of the bracha, would still apply, and therefore, if one takes recreational drugs, he should stop for a moment and express his gratitude to Hashem for creating these excellent adventures.
I want to point out another thing- do you think this would have been printed in Hapardes or Hamaor? I don't think so. Let us thank the internet for this particular quirky aspect of Harbatzas Torah.