Is whey halal?
Depends on the source
- Usually made from
- Milk (cheesemaking)
- Vegan
- No
What is whey?
Whey is the watery part of milk left over when cheese curds are separated. It is dried into whey powder, or filtered and concentrated into whey protein. Whey made by adding acid to milk, as for some fresh cheeses, is called acid whey; whey from rennet-set cheese is sweet whey.
Why it's marked “Depends on the source”
Whey itself is milk, which is halal. The doubt comes from how the cheese was made: if animal rennet from a non-halal source curdled the milk, some certifiers and scholars treat the whey as doubtful too, while others do not, since the rennet is used in tiny amounts and most of it stays in the cheese. Whey from microbial rennet or acid-set cheese raises no issue.
Where views differ
Views differ on whether whey from cheese made with animal rennet of a non-halal source is affected. Some consider the whey a separate product of milk and permissible; others ask for whey from cheese made with microbial or halal rennet. Certifiers set their own rules here.
How to check the label
On whey protein and products with whey powder, look for a halal certificate from a recognised body or a vegetarian mark, which means non-animal rennet was used. Otherwise ask the manufacturer which rennet the cheese plant uses.
Where you'll find it
- protein powder
- biscuits and baked goods
- chocolate and sweets
- crisps and snacks
- infant formula
Good to know
- US rules define whey as the liquid separated from the curd in cheesemaking; sweet whey and acid whey are named by how the milk was set.
- Whey protein isolate and concentrate are filtered forms of the same whey, so the same question applies to them.
Ingredients people often ask about
See all 89 E-numbers in the halal checker
This list describes where additives usually come from. It isn't a religious ruling, and manufacturers can change their sources. Last reviewed: 14 October 2026.
Sources
Frequently asked questions
Is whey halal?
Depends on the source. Whey itself is milk, which is halal. The doubt comes from how the cheese was made: if animal rennet from a non-halal source curdled the milk, some certifiers and scholars treat the whey as doubtful too, while others do not, since the rennet is used in tiny amounts and most of it stays in the cheese. Whey from microbial rennet or acid-set cheese raises no issue.
What is whey made from?
Whey is the watery part of milk left over when cheese curds are separated. It is dried into whey powder, or filtered and concentrated into whey protein. Whey made by adding acid to milk, as for some fresh cheeses, is called acid whey; whey from rennet-set cheese is sweet whey.
Is whey vegan?
No. Whey comes from milk, so it isn’t vegan, though it is vegetarian when the cheese was made with non-animal rennet.