If scientists could grow human organs inside of pigs, would it be halachically acceptable to receive a transplant of such an organ?

A recent article in National Public Radio about US and British researchers working towards a potential scientific and medical advancement raised this question:

A handful of scientists around the United States are trying to do something that some people find disturbing: make embryos that are part human, part animal.

The researchers hope these embryos, known as chimeras, could eventually help save the lives of people with a wide range of diseases. Perhaps the boldest hope is to create farm animals that have human organs that could be transplanted into terminally ill patients.

Talking with my religious friends about this article, most of them expressed shock and dismay at scientists playing G-d. Others pointed out the dangers in creating frankenstein chimeras which may or may not break the Torah's prohibition on mixing seeds. Still others raised ethical issues around using human embryos for medical research of any kind.

But as I thought deeper about it, if the issue is saving a person's life, perhaps pikuach nefesh applies here. On the other hand, I can sympathize with the various objections raised by my friends.

  • 1
    As far as I know. The halacha is that you can receive an organ transplant from an actual pig. There have been pig heart transplants before.
    – Aaron
    May 19, 2016 at 22:29
  • 1
    Insulin for diabetics used to be manufactured similarly: americanhistory.si.edu/blog/2013/11/…
    – user2411
    May 20, 2016 at 0:06
  • judaism.stackexchange.com/questions/71481/…
    – user2411
    May 20, 2016 at 11:09
  • Why would this be an issue of kilayim? The mother is a pig, the father is a pig, there's just injected human DNA. Iirc, it's a pig embryo injected with induced pluripotent stem cells, not human embryo cells (which aren't independently alive anyhow...). May 20, 2016 at 14:41
  • Second issue: Chazal do not allow for adding pikuach nefesh where the danger is not imminent. That's why there's no exception for a Cohen attending medical school to work on a cadaver - future potential for life saving doesn't count. May 20, 2016 at 14:43

3 Answers 3


One question would be whether such an organ would be considered pig and thus forbidden to consume. (The title to your question perhaps suggests that this is the crux of the question, as it focuses on the transplant of the organ, not the creation of the organ. That being the case, I will focus on this question).

Even if it were, the (near) universal rule in Judaism, is that every prohibition may be violated to save a life except for the three cardinal sins, which do not involve organ transplants from pigs. If the organ transplant was not vital for one's health, it would still not violate the prohibition of consuming pig because one is not eating it.

The only question would be whether there is a prohibition against benefit from pig as distinct from a prohibition to eat it.

The Mishna Sheviit (7:3) states that one is prohibited from engaging in commerce with certain prohibited foods. The Yerushalmi there clarifies that there is a prohibition to engage in commerce with any food that is Biblically forbidden.

The question is therefore whether this represents a universal prohibition against benefit from forbidden foods, or an injunction against commerce in particular.

Rashba (Responsa: 3:223) writes that there is no universal prohibition to benefit from pigs; only a rabbinic injunction against engaging in commerce with them.

אם החזיר מותר בהנאה, במה שהתרת ליקח אותו בחובו? חדא: שהוא בעצמו אינו אסור בהנאה, דבר תורה, ואפילו לעשות בו סחורה, אלא מדבריהם

According to most authorities this limit on commerce is a rabbinic injunction. (Cf. Bartenura in Sheviit there, and Beit Yosef YD 117). They specify that this prohibition only applies when the commerce may lead to consumption of the food. (Cf. Shach YD 117:2). This would be another reason why the rabbinic injunction against commerce would not apply to a transplant; the transplant would not lead to consumption of pig.

Accordingly, even in cases where there is no danger to life, there would be no prohibition on using pig organs.

The remaining problems you raise are:

  • "scientists playing G-d"
  • The dangers in creating Frankenstein chimeras which may or may not break the Torah's prohibition on mixing seeds.
  • Still others raised ethical issues around using human embryos for medical research of any kind.

The first two are not formal prohibitions and even if they were they would be overruled by considerations of saving a life.

The last concern raised; use of embryo tissue for research is the only concern that could potentially override saving a life, as there is the possibility that certain cases of abortion constitute murder.

See these questions related to abortion: May a non-Jew have an abortion?, Is a Jew permitted to have an abortion?, and At what point is a child considered living.

  • The embryo tissue used in these studies is generally nonviable.
    – LN6595
    Apr 12, 2019 at 17:41

myJewishlearning adresses the question and states this is unequivocally permitted

There is no halakhic problem with pigskin and pig heart valves. Beyond that, there’s a very important tenet of Judaism called pikuah nefesh, or, saving a life. According to Jewish law, any of the mitzvot in the Torah (except idolatry, murder, and forbidden sexual relationships) can and in fact should be violated in order to save a person’s life; the pikuah nefesh principle is that strong. This means that even if the use of pig parts wasn’t generally allowed by halakhah, when people’s lives are at stake, we are commanded to do whatever is necessary to save them.

They also quote R Avi Shafran (from Agudath Israel of America) saying refusing a pig's heart would be silliness.

There is a full article on the topic by Fred Rosner, the well-known Jewish medical ethicist, Pig organs for transplantation into humans: a Jewish view, in the Mount Sinai Journal of Medicine (1999 Oct-Nov;66(5-6):314-9) but I'm not sure it is available online.


This question is relevant to understand that each of negative mitsvot has a spectrum and is not an idea only. In Torah, Orthodoxy and Orthopraxy ara alloyed which each other. When Tora prohibit to eat pig, the message is not "Pig is an abomination", but in each word of Torah, there is also a mean of though, that can lead to discover human bad behaviors through observation of certain animals. E.g. people tend to compare rudeness to Swin behavior.

However, to understand correctly Torah, we need to read carefully the verses about our question, the chazal and poskim:

  1. Leviticus 11, 3 - 8:
    אַ֤ךְ אֶת-זֶה֙ לֹ֣א תֹֽאכְל֔וּ מִמַּֽעֲלֵי֙ הַגֵּרָ֔ה וּמִמַּפְרִסֵ֖י הַפַּרְסָ֑ה... וְאֶֽת-הַֽ֠חֲזִ֠יר כִּֽי-מַפְרִ֨יס פַּרְסָ֜ה ה֗וּא וְשֹׁסַ֥ע שֶׁ֨סַע֙ פַּרְסָ֔ה וְה֖וּא גֵּרָ֣ה לֹֽא-יִגָּ֑ר טָמֵ֥א ה֖וּא לָכֶֽם: מִבְּשָׂרָם֙ לֹ֣א תֹאכֵ֔לוּ וּבְנִבְלָתָ֖ם לֹ֣א תִגָּ֑עוּ טְמֵאִ֥ים הֵ֖ם לָכֶֽם:‏
    Speak unto the children of Israel, saying: These are the living things which ye may eat among all the beasts that are on the earth... And the swine, because he parteth the hoof, and is cloven-footed, but cheweth not the cud, he is unclean unto you. Of their flesh ye shall not eat, and their carcasses ye shall not touch; they are unclean unto you.
  2. Rashi summarized briefly the chazal lecture of our verses:
    מבשרם. על בשרם באזהרה, ולא על עצמות וגידין וקרנים וטלפים: ובנבלתם לא תגעו. יכול יהו ישראל מוזהרים על מגע נבלה, תלמוד לומר אמור אל הכהנים וגו' (ויקרא כא, א.), כהנים מוזהרין, ואין ישראל מוזהרין, קל וחומר מעתה, ומה טומאת המת חמורה לא הזהיר בה אלא כהנים, טומאת נבלה קלה לא כ"ש, ומה תלמוד לומר לא תגעו, ברגל. וזה שאמרו חייב אדם לטהר עצמו ברגל: ‏
    of their flesh: The [Scriptural] prohibition applies [only] to the “flesh” [of an unclean animal], but not its bones, sinews {e.g. a mitral valve (eating is allowed, but transplanting need not this additional permit)}, horns, or hooves . — [Torath Kohanim 11:74] מבשרם: על בשרם באזהרה, ולא על עצמות וגידין וקרנים וטלפים:

    and you shall not touch their carcasses: One might think that Israelites are prohibited to touch a carcass.

    Scripture, however, says, “Say to the kohanim …[(a kohen) shall not defile himself for a (dead) person among his people]” (Lev. 21:1); thus, kohanim are prohibited [from defiling themselves by human corpses], but ordinary Israelites are not prohibited. Now a kal vachomer can be made: Since in the more stringent case of defilement by a human corpse, only kohanim are prohibited, then in the more lenient case of defilement by animal carcasses, how much more so [should only kohanim be prohibited! If so,] what does Scripture mean by, “you shall not touch their carcasses”? [It means that Israelites may not touch animal carcasses] on the Festivals [since at those times they deal with holy sacrifices and enter the Temple]. This is what [the Sages] said: A person is obligated to cleanse himself on Festivals. - [R.H. 16b, Torath Kohanim 11:74]
  3. About human flesh. Sefer Hachinuch Mitsva 154
    ובשר אדם אף על פי שנקרא האדם נפש חיה ואינו מעלה גרה ושוסע שסע, אין בשרו בכלל אסור בהמה טמאה לעבר עליו בלאו, ולפיכך האוכל מבשרו או שותה מחלבו, בין חי בין מת, אין לוקין עליו, אבל מכל מקום אסור הוא בעשה, שהרי מנה הכתוב שבעת מיני חיה ואמר בהן (דברים יד ד) זאת החיה אשר תאכלו, מכלל שכל שהוא חוץ מאלו לא תאכלו, ולאו הבא מכלל עשה עשה זהו דעת הרמב''ם זכרונו לברכה. (מאכלות אסורות ב ג) ‏
    Human flesh, despite man is called "living thing", don't cheweth the cud, is not wholly cloven-footed, he is not included in the prohibition to eat unclean animals as a "Lav" (thou shalt not). Therefore, who eat his flesh and drink his milk, no matter if the human is live or death, will not be flagelled. but there is an "Issur Asse" because he is not counted in the seven species. About seven species only Tora said (Deuteronomy 14, 14) "These are the beasts which ye may eat: ... " etc...
    אבל הרמב''ן זכרונו לברכה כתב (ויקרא שם יג) שבשר האדם אפילו עשה אין בו, והביא ראיה ממה שאמרו זכרונם לברכה (כדיתות כא ב) דם מהלכי שתים וחלבם, אפילו מצות פרישה אין בו. וכתב הוא זכרונו לברכה דהוא הדין לבשר שמתר כמו הדם, שאם לא כן, איך יהא מתר הדם, וכמו שאמרו זכרונם לברכה (שם כד א) דם של בין השנים מוצצו ובולעו, והא קימא לן (בכורות ה א) כל היוצא מן הטמא טמא. ומכל מקום, בשר (ישראל) מת, אסור בהנאה. ויתר ראיותיו בספרו ושאר פרטי המצוה מבארים בפרק שלישי מחלין ובמקומות אחרים [הלכות מאכלות אסורות פ''ב] ‏
    But the Ramban of blessed memory said that there is not even "Issur Asse" {followed by Shulchan Aruch YD 66, 10; 81, 7} ... but anyway, human flesh is prohibited to profit.
  4. In conclusion there is no problem with swine flesh in non-eating profits. Medical benefit through it, and a fortiori enable people to stay alive is a great mitsva.

Problem of mixing seed and greffon or clonages ore genetic manipulations are not the same.

  • The question seemed to more about "playing God" (by sort-of creating a new type of animal) and the prohibition on mixing seeds (i.e. kil'ayim) — not about whether one can use a pig part in a transplant.
    – msh210
    May 20, 2016 at 13:17
  • @msh210 you are right . I'll delete it.
    – kouty
    May 20, 2016 at 13:58
  • @msh210 "human organs inside of pigs"
    – kouty
    May 21, 2016 at 23:44

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