Whey powder
Whey powder is the dried protein fraction left over from cheese-making, used in protein supplements, baked goods, and processed foods. Because it comes from milk, it is not vegan and contains milk protein (an allergen) and lactose, so it is relevant for lactose intolerance and low-FODMAP diets.
Whey is the liquid by-product of cheese production, dried into a concentrate or isolate. It naturally contains lactose (milk sugar) and whey proteins such as beta-lactoglobulin, alongside small amounts of minerals and fat.
Because it retains milk’s lactose and protein, products with whey powder are unsuitable for vegan diets and must be labelled for milk allergy under EU rules; the lactose content also makes it relevant for lactose intolerance and low-FODMAP diets, even in small amounts.
Who this affects
Avoid
- Vegan: Animal-derived (milk).
Caution
- Lactose intolerance: Contains lactose.
Frequently asked questions
Usually yes. Whey is derived from milk, and lactose is the natural sugar in dairy, so whey powder typically contains lactose (some refined whey protein isolates contain much less). Lactose-intolerant people may react depending on the amount. Check the label, as lactose content is not always stated.
No. Whey is a milk protein and therefore animal-derived, so it does not fit the Vegan Society definition of veganism, which excludes all products derived from animals including dairy. Products listing whey are not suitable for vegans. Plant proteins such as soya, pea or rice are vegan alternatives.
No. Whey and casein are the two cow’s-milk proteins that cause allergic reactions, so whey is not safe for people with a milk allergy. “Lactose-free” does not mean milk-protein-free — those products still contain casein and whey. This is safety-critical, so always rely on the physical label and medical advice.
Yes. Whey is milk-derived, and “milk and products thereof (including lactose)” is one of the 14 allergens that must be declared under EU Regulation (EU) No 1169/2011. Any whey ingredient must be emphasised in the ingredients list. The only labelling exception in the regulation is whey used for making alcoholic distillates.
A milk allergy is an immune reaction to milk proteins such as whey and casein and can be serious; lactose intolerance is difficulty digesting the milk sugar lactose and is not an immune response. Someone with a milk allergy must avoid whey entirely; someone lactose intolerant reacts to the lactose whey may contain. Follow the label and professional advice.
Protein powders, chocolate, biscuits, baked goods, crisps, sauces, margarine and many processed foods — listed as whey, whey powder, whey protein, casein or milk solids. Because milk is a mandatory labelled allergen in the EU, these must be highlighted. Always read the label, as “non-dairy” claims do not always guarantee milk-free.