Whey Protein Isolate
Whey filtered to around 90 percent protein before flavoring, with most of the fat and lactose removed. The leanest option per calorie, and usually the best tolerated by anyone who bloats on concentrate.
Isolate or concentrate
The difference is how much filtering has been done.
Concentrate is roughly 70 to 80 percent protein. It keeps more fat, lactose and carbohydrate, which makes it cheaper and creamier to drink.
Isolate is filtered further, to about 90 percent protein before flavouring. Most of the fat and lactose is removed.
What that means in practice. Nearly all the calories in an isolate are protein, which matters when you are counting them. Lactose is largely filtered out, which is why isolate suits many people who get bloating from concentrate. It is not a substitute for a milk allergy, since the protein itself is the allergen, but for lactose sensitivity the difference is real. And it digests slightly faster with no fat to slow gastric emptying.
Where concentrate wins is price and taste. If lactose does not bother you and you are not counting calories tightly, concentrate is perfectly good and better value per gram.
Narrow it down
Getting the most from an isolate
Written by our staff. Nobody here earns commission.
What the filtering actually removes
Isolate is not a different protein. It is the same whey, filtered further.
| Protein | Rises from 70 to 80 percent up to around 90 Lactose |
That last row is the honest trade. An isolate is lean by design, which means it will never drink like a milkshake. If you want a thick, dessert-like shake, a blend or a dedicated pudding product is the right choice and there is nothing wrong with that.
Lactose intolerance is not a milk allergy
These get confused constantly, and the distinction decides which product you can use.
Lactose intolerance means you lack enough lactase to break down the milk sugar. Since isolate has most of the lactose filtered out, many people who react badly to concentrate tolerate isolate without trouble. Worth trying before giving up on whey entirely.
A milk allergy is an immune response to the milk protein itself. Whey and casein are both milk proteins, so no amount of filtering helps. Egg white protein is complete, dairy free and naturally higher in leucine than most plant options. A rice and pea blend is the fully vegan route.
If you get bloating from whey and it is not lactose, it may simply be drinking it too fast on an empty stomach, or the sweeteners rather than the protein. Sugar alcohols in particular cause more digestive trouble than people realise.