What’s In That Pill? Kashrus of Medications – Part 1: Lactose

Lactose, also referred to as “milk sugar,” is a common ingredient in the pharmaceutical industry. Its widespread use in various medications prompts important halachic considerations. Central among these are questions regarding its status: is lactose classified as Chalav Nachri or as milk obtained from a non-kosher animal? Furthermore, does lactose retain the halachic status of milk in terms of the laws of Basar b’Chalav?

We will begin our discussion with a brief overview of the lactose production process:

            Cheese production begins with separating the solid curds from the liquid whey, which are then used to make cheese. Heating the curds causes additional whey to be expressed. To produce lactose from the whey, the whey proteins must be extracted from the lactose-rich liquid. The whey is commonly referred to as “Mei Gevina”. Next, the Mei Gevina are cooked, causing solidified components (ricotta) to rise to the surface, where they are carefully removed. The remaining liquid (“Mei Chalav”) is cooled under controlled conditions, forming lactose crystals that are separated, dried, and milled into powder for commercial use. In the pharmaceutical industry, lactose is used primarily as a bulking agent to increase the volume of medications. The lactose content of a drug is often significant and may constitute the majority of the formulation.

            Chaza”l instituted a Gezeira against Chalav Akum out of concern that a Nachri might substitute Kosher milk with non-Kosher milk or possibly mix the two together (Avoda Zara 35b). The Pri Chadash and Chasam Sofer (see Pischei Teshuva 115:3) disagree as to whether this Gezeira applies when it is unlikely that the Nachri would do so.

            Famously, R’ Moshe Feinstein (Igros Moshe 1:47) ruled leniently in cases where there is government oversight of milk production that makes it illegal to market cow’s milk when other substances have been added to it. R’ Moshe claimed that both the Pri Chadash and Chasam Sofer would agree in this case, as government oversight grants us “Yedia Berura – absolute certainty”, which is Halachically equivalent to testimony by Kosher witnesses. Further discussion is beyond the scope of this essay.

In most cases, lactose is treated more leniently because it is derived from Mei Gevina, a byproduct of the cheese-making process. The Rema rules (Y.D. 115:2) that milk set aside to make cheese is not Chalav Akum, as non-Kosher milk does not produce cheese. The same should apply to lactose, at least Bedieved.^[1]

A further leniency that can be applied to lactose is the view of the Ri’az (see the Darchei Teshuva ibid. 1) that Mei Gevina is not considered milk and was not included in the Gezeira of Chalav Akum. When lactose is used in medications, there are further grounds for leniency. Since the other ingredients render the lactose inedible, the Gezeira of Chalav Akum is surely not applicable.

Based on these arguments, R’ Elyashiv (Kovetz Teshuvos 1:73) permitted the use of unsupervised lactose in medications. In fact, he even extended this to the Halachos of Basar b’Chalav. Though the Shach rules (Y.D. 87:17) that if Mei Gevina falls into a meat dish, it is forbidden due to Basar b’Chalav; that is only due to Maris Ayin. One may, however, consume Mei Gevina immediately after eating meat.

On the other hand, the Achronim present an argument for stringency concerning lactose. They note that Chaza”l also forbade Gevinas Akum – cheese produced by a Nachri due to the concern that the cheese may have been set in the stomach of a non-Kosher animal. Since lactose is produced by heating Mei Gevina, it would have absorbed taste from the cheese and acquired the status of Gevinas Akum, which is not subject to the leniencies of Chalav Akum.

            Consequently, some authorities argue that the lactose produced in this manner acquires the halachic status of Gevinas Akum. Unlike the case of Chalav Akum, the leniencies discussed earlier do not necessarily apply to Gevinas Akum. Therefore, the use of lactose derived from such sources could be subject to more stringent halachic considerations.

The counterarguments are:

1. When Mei Gevina is cooked, the liquid that separates does not absorb the taste.
2. The cooking took place before the Mei Gevina was owned by a Jew (for whom the Gezeira of Gevinas Akum applies). It is thus considered “Ta’am d’Heteira”.

Regardless, this would only be a concern if the Mei Gevina reached a temperature of Yad Soledes Bo during the cooking. l’Halacha, some Poskim rule leniently, including R’ Moshe Feinstein and R’ Elyashiv (ibid.). See also the Shevet haLevi 2:86.^[2]

If a person has eaten meat, may he take a medication that contains lactose?

If the medication has a bitter taste and is considered Eina R’uya l’Achila (not fitting for consumption), it does not have the status of a food and may be eaten after meat (although it is preferable not to eat it together with meat). However, many medications have a pleasant taste.

We clarified that lactose is derived from Mei Chalav, which does not contain any real cheese. The Shulchan Aruch rules (Y.D. 87:8):

Some say that “Nisyubei d’Chalva” (milk that is secreted when cheese solidifies) is not considered Mei Chalav and is Asur Min haTorah. Mei Chalav is [the product] when the “Nisyubei” is cooked, causing the whey to rise to the top and leaving only liquid. This is Mei Chalav.

In Se’if 6 (ibid.), the Shulchan Aruch rules that cooking meat in Mei Chalav is only Asur mid’Rabbanan. Here in Se’if 8, he identifies Mei Chalav, and argues that the liquid that is first excreted by the cheese is considered milk, and it would be Asur Min haTorah to cook it with meat. Mei Chalav is produced only at the next stage, when the liquid is cooked and further solid matter (i.e., ricotta) is removed, leaving only liquid.

Rav Shmuel Wosner zt”l discusses this subject at length in Shevet haLevi 7:118:

Question: Various medications contain a small amount of lactose. Is this a reason to prohibit their use together with meat?

Answer: I heard from an expert who is a true Yirei Shamayim that lactose is produced by evaporating all the water components of whey. In my humble opinion, it is no longer considered milk at all, at least Min haTorah, and it is not comparable to milk powder. There, the essence of the milk remains, except that it is dried out. With the addition of water, it returns to regular milk. This is not so with lactose, where only the sugar components of the milk remain.

Moreover, regarding whey itself, there are two opinions in Shulchan Aruch, Y.D. 87, as to whether it is considered milk Min haTorah. Though we are stringent, that is only for Mei Chalav, not “Meimei Chalav”, as evident from the Poskim there and in Siman 81.

In any event, regarding Basar b’Chalav, since it is only a small admixture within the pills, and since there are several opinions in Y.D. 89 that a cooked dish containing cheese is preferable to cheese itself, at least with respect to eating one after the other, one may take the medication after a meat meal. There is no need to wait, as the Rema in 89:1 permitted doing this m’Ikar haDin after Bentching.

The basic Halacha appears to be that there is no concern at all regarding a mixture containing a minimal amount of lactose, at least in the case of a Choleh she’Ein Bo Sakana. See the Darchei Teshuva, Y.D. 87:25, who cites the Arizal, Sha’ar haMitzvos, Mishpatim, who relates that he knew of people who would not eat sugar made from sweet reeds together with meat, since the craftsmen prepare it by introducing goat’s milk into it. However, he writes that he saw the Arizal eat it together with meat.

            R’ Wosner’s Teshuva invokes multiple lines of reasoning. Essentially, based on the view cited by the Shulchan Aruch that consuming Nisyubei d’Chalva with meat is prohibited Min haTorah, lactose would also be considered Asur Min haTorah.

R’ Wosner’s description of the production of lactose corresponds to the Shulchan Aruch’s definition of whey. However, those knowledgeable about lactose production say that it is produced in two stages and is extracted from water from which all the cheese components have already been removed. In that case, it has the status of Mei Chalav, which is only Asur mid’Rabbanan. If so, it is permitted for a Choleh she’Ein Bo Sakana.

In any case, even R’ Wosner only permits this because it is a “small admixture”, an assumption that must be examined for each medication individually. He also relies on the Rema’s ruling that m’Ikar haDin one may consume milk after one has finished a meat meal. Ideally, waiting an hour and thoroughly cleaning the mouth and teeth is recommended, as this approach best addresses any potential concerns.

[1] The Shach rules (ibid. 22) that one should only be lenient in a case of Hefsed Meruba, however, the Pri Chadash is more lenient. Regardless, if the person milking the cow will not be producing the cheese, the Rema’s ruling does not apply, and the milk becomes Asur as Chalav Akum.

[2] See also v’Alehu l’Terufa (R’ Chaim Metzger and R’ Chaim Malachi, 2013) p117-120 for an extensive discussion of this topic, citations of additional Poskim who discuss this question.