Difference Between Whey Protein and Isolate Protein

The main difference between whey protein and isolate protein is that whey protein is a mixture of globular proteins isolated from whey whereas isolate protein consists of 90% of protein.

Whey protein is the best form of protein consumed for muscle building, Whey protein concentrate (WPC), whey protein isolate (WPI), whey protein hydrolysate (WPH), and native whey protein are the four types whey protein available in the market. Generally, whey protein concentrate only contains 80% of protein and small amounts of fat and carbohydrate. Both WPC and WPI have the same effect. Whey protein concentrate is cheap and easy to manufacture. Hence, it is the most widely consumed form of whey protein.

Key Areas Covered

1. What is Whey Protein
     – Definition, Types, Importance
2. What is Isolate Protein
    – Definition, Facts, Production
3. What are the Similarities Between Whey Protein and Isolate Protein
     – Outline of Common Features
4. What is the Difference Between Whey Protein and Isolate Protein
     – Comparison of Key Differences

Key Terms: Composition, Isolate Protein, Protein Content, Whey Protein, Whey Protein ConcentrateDifference Between Whey Protein and Isolate Protein - Comparison Summary

What is Whey Protein

Whey protein contains a mixture of globular proteins isolated from whey. Whey is the leftover liquid material of the coagulation procedure of cheese production. It consists of soluble components of milk at pH 4.6. Therefore, whey resembles 5% lactose solution with lactalbumin and some minerals. Whey processing involves drying or removing the fat and other non-protein content so that it increases the protein content. However, whey protein is responsible for some forms of milk allergies.  

Difference Between Whey Protein and Isolate Protein

Figure 1: Separation of Whey from Curd

Whey protein is available in the market as a dietary supplement and there are four types of it. They are concentrate, isolate, hydrolysate, and native protein.

  1. Whey protein concentrate (WPC) – WPC contains significant levels of fat and cholesterol and high amount of carbohydrates in the form of lactose, when compared to the other forms. Typically, WPC contains 29-89% of whey protein by weight. Hence, it is slight to mild milky in taste.

  2. Whey protein isolate (WPI) – WPI is a processed form of whey protein that does not contain fat as well as lactose. By weight, WPI contains 90% of whey protein.

  3. Whey protein hydrolysate (WPH) – WPH contains pre-digested and partially hydrolyzed whey protein that eases metabolism. Therefore, WPH is costly in general. The highly hydrolyzed form of whey protein is the least allergenic.

  4. Native whey protein – It is not a by-product of cheese, but an extract of skim milk. Both concentrate and the isolate forms are available in the native whey protein.

What is Isolate Protein

Isolate protein, or whey protein isolate (WPI), is a processed form of whey protein that does not contain fat and lactose. It contains 90% whey protein by weight. It is virtually carbohydrate-free, lactose-free, fat-free, and cholesterol-free. On the other hand, it contains the highest percentage of pure protein. 

Main Difference - Whey Protein vs Isolate Protein

Figure 2: Regular Milk and Whey Protein

WPI production involves two methods: ion exchange method or membrane filtration method.

  1. Ion exchange method – it uses the surface charge characteristics of whey protein in the separation. Little alterations of pH make the attractions between protein molecules and molecules in the ion exchanger.

  2. Membrane filtration – it uses both microfiltration and ultrafiltration to separate whey protein based on the size of the protein molecules.

Similarities Between Whey Protein and Isolate Protein

  • Whey protein and isolate protein contain the globular proteins left over during the cheese production.

  • Both contain high concentrations of branched-chain amino acids (BCAAs).

  • The body quickly absorbs both the proteins.

  • They both serve as a fuel for working muscles.

  • Both stimulate protein synthesis.

  • They are used as dietary supplements for muscle building.

  • Both have a milky taste.

Difference Between Whey Protein and Isolate Protein


Whey Protein: Whey extract that contains a mixture of globular proteins.

Isolate Protein: A processed form of whey protein that does not contain fat and lactose


Whey Protein: The liquid by-product of the cheese production

Isolate Protein: Whey protein processed to remove fat and lactose


Whey Protein: Concentrate, isolate, hydrolysate, and native whey proteins

Isolate Protein: A type of whey protein

Protein Content

Whey Protein: 29-89% of protein by weight

Isolate Protein: 90% of protein by weight


Whey Protein: Contains a higher amount of lactose and significant levels of fat and cholesterol

Isolate Protein: Carbohydrate-free, lactose-free, fat-free, and cholesterol-free


Whey Protein: Maybe allergenic

Isolate Protein: Better for low-calorie diet and lactose intolerance


Whey protein is the leftover of the cheese production which contains globular proteins. Generally, whey protein contains 80% of protein by weight. It also contains carbohydrates, fat, and cholesterol. But, isolate protein contains 90% of protein. It contains fewer amounts of carbohydrates, fat, and cholesterol. The main difference between whey protein and isolate protein is the protein content, fat, and carbohydrate levels of the two types of whey proteins.


1. Kendall, Krissy. “Your Expert Guide To Whey Protein.” Bodybuilding.com, 12 Apr. 2018, Available Here

Image Courtesy:

1. “Separating the curd and whey” By Jesse Gillies –  (CC BY 2.0) via Commons Wikimedia
2. “Protein shake” By Sandstein – Own work (CC BY 3.0) via Commons Wikimedia

About the Author: Lakna

Lakna, a graduate in Molecular Biology and Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things. She has a keen interest in writing articles regarding science.

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