There are mixed opinions on whether or not Whey Protein is Halal. The substance itself is halal since it’s a byproduct of cheese fabrication process.

In fact, Whey is a byproduct of cheese fabrication process where milk is curdled by adding an element called ‘Rennet’ or ‘pepsin’.

Rennet is an enzyme derived from stomachs of calves and goats while pepsin is derived from the stomach of swine.

From there we can distinguish two scenarios: 1) The milk is curdled with pepsin, then the obtained whey is haram (illicit). 2) The milk is curdled with rennet, and here we have two other scenarios: a) The rennet is from a ritually slaughtered animal, then the produced whey is halal. b) The rennet is obtained from non slaughtered animals.

In the latter scenario, we have divergence between the different Islamic schools of thought (Fiqh).

2 Opinions on Rennet from Non Slaughtered Animals

There are four schools of thought (Fiqh) on the matter, and we will delve into each and see if we can’t find an answer to the elusive question: is Whey Protein Halal?

All four schools of thought have no difference of religious opinion, but merely differ in terms of Rennet

Rennet is haram (illicit):

For Imams Malik, Shafi’i and according to a version of Ahmad Ibn Hanbal the Rennet produced in stomachs of non slaughtered animals is impure.

Rennet is halal (licit):

For Abu Youssouf and Az-Zuhayli, it is pure if it is still solid and has not gone through the liquidation process. On the other hand, for Abu Hanifa, Ibn Taymiyyah, Ibn Qudama al-Maqdisi and according to another version of Ahmad Ibn Hanbal – the Rennet is pure without conditions.

It was also reported that The Companions, including Salman al-Farisi (at the time of the Caliphate of ‘Omar ibn Al-Khattab), ate cheeses made by the Zoroastrians who used animal rennet and claimed that it was licit to eat when asked the question.

Furthermore, many scholars of the first generations have asserted the legality of cheeses such as Ibn Taymiyyah (Ferkous, March 2018), Qurtubi (Virtualave, no date specified) and Bukhari (Sahih al-Bukhari: The Early Years of Islam, by Imam al-Bukhari, 2013.)

Related: Is Vinegar Halal?

Are there any halal whey brands?

Thanks to the growing halal market and the awareness of Muslim consumers and manufacturers alike, there are more and more halal supplement brands hitting the market of which we can cite a few:

Conclusion

Since there are divergent opinions among Suny schools regarding the source of rennet, each Muslim can, therefore, forge its own opinion on the matter.

Whey protein that is Halal will often carry the certification from credible and recognized organisms, and if you are ever in any doubt, try Halal Certified Whey Protein, Egg White Protein Powders, or Vegan protein powders, instead!