Isolate vs concentrate is a question about how far a protein has been separated from the food it came from. Both words appear on whey, soy and other protein powders. ICMR-NIN's Dietary Guidelines for Indians, 2024, note that protein powders are made from eggs, milk, whey, soybeans, peas or rice.1 The source sets the starting point, and the words concentrate and isolate tell you how much of everything else was taken out along the way.
What a concentrate keeps
A concentrate has had much of the water, sugar and other material removed, but not all of it. For whey, a review of protein types by Hoffman and Falvo puts concentrate anywhere from 25 to 89% protein.2 The same powder can hold 10 to 55% lactose, the sugar in milk, and 2 to 10% fat.2 That is a wide band, which is why two tubs can both say concentrate and still list quite different protein figures.
Soy works on the same principle. USDA lists soy protein concentrate at 63.63 g of protein in 100 g, and that same 100 g still carries 25.41 g of carbohydrate and 5.5 g of fibre.3
What an isolate removes
An isolate goes further. In the same review, whey isolate is 90% protein or more, and only about 0.5% each of lactose and fat.2 Soy protein isolate in USDA's table has 88.32 g of protein in 100 g and no carbohydrate or fibre at all.4
On a 30 g scoop of soy, that is the gap between about 19 g of protein from the concentrate and about 26.5 g from the isolate. The protein in both comes from the same bean. What changes is how much carbohydrate and fibre is left around it, in the same way that lactose and fat change in whey.
What each form gives you on the label
When people talk about isolate protein benefits, they usually mean more protein in each gram, and less lactose and fat in each scoop of whey.2 Concentrate protein benefits are easier to judge from the label than from the name. A concentrate gives a little less protein per gram and keeps more of the starting food, whether that is lactose and fat in whey or some fibre in soy.
So the protein isolate vs concentrate question has no single answer for everyone. If you want the most protein in the smallest scoop, an isolate gives you that. If you are happy with a lower protein share and more of the original food, a concentrate suits you, and its label tells you exactly how much protein you get.
Working out the protein share from a label
Most labels give protein per serving rather than a percentage, but the share is easy to find. It is the protein in one serving as a part of that serving's weight. A 30 g scoop that lists 24 g of protein is 80% protein, since 24 is four-fifths of 30, and that sits inside the concentrate range. A 30 g scoop that lists 27 g is 90%, the level the review gives for isolate.2
That check matters most with concentrates, because their range is so wide. It also helps when a tub uses a large scoop. A 40 g scoop with 24 g of protein is only 60% protein, even though the 24 g figure looks the same as before.
Reading isolate and concentrate on a pack
The word on the front of the pack tells you which form a powder is, while the protein grams next to the serving tell you what you actually get. ICMR-NIN also notes that some protein powders mix proteins from more than one source, and that powders can contain added sugars, non-caloric sweeteners and flavourings.1 So the ingredients list and the sugar figure deserve as much attention as the word on the front.
Horlicks Protein and the word concentrate
Horlicks Protein Unflavoured combines whey protein concentrate and fermented yeast protein, according to its pack, while the Chocolate and Coffee sachets use fermented yeast protein. Every sachet weighs 36 g and carries 24 g of protein, mixed into 200 ml of cold water or milk. Because that protein is already given in grams for the whole sachet, there is no percentage to work out.
At 0.83 g per kg, ICMR-NIN's daily protein for a 65 kg adult is about 54 g, and one sachet supplies 24 g of it.1 The bottled milkshake is labelled in another way again, as ultra-filtered milk protein, with 20 g in each 240 ml bottle.
In summary, isolate and concentrate describe how far a protein has been separated from the food it came from. A concentrate keeps more of that food, so whey concentrate ranges from 25 to 89% protein and soy concentrate is about 64%. An isolate removes more, so whey isolate is 90% or more and soy isolate about 88%, with very little lactose, fat or carbohydrate left. The protein grams for one serving, the sugar figure and the ingredients list tell you more than the name does. A Horlicks Protein sachet lists its protein in the same direct way, 24 g in 36 g.
Sources
1. ICMR-National Institute of Nutrition. Dietary Guidelines for Indians, 2024. https://nin.res.in/dietaryguidelines/pdfjs/locale/DGI_2024.pdf
2. Hoffman JR, Falvo MJ. Protein, which is best? Journal of Sports Science and Medicine, 2004. PubMed 24482589. https://pmc.ncbi.nlm.nih.gov/articles/PMC3905294/
3. USDA FoodData Central. Soy protein concentrate, produced by alcohol extraction. FDC 172447. https://fdc.nal.usda.gov/food-search/?query=172447&type=SR%20Legacy
4. USDA FoodData Central. Soy protein isolate. FDC 174276. https://fdc.nal.usda.gov/food-search/?query=174276&type=SR%20Legacy