What is Whey Protein Isolate and How Does It Differ from Whey Concentrate?

whey protein isolate

The average sedentary person gets enough protein in their diet. However, older people and those who exercise regularly need more than the current recommendations. If you do any form of endurance exercise or lift weights, your protein requirements are higher than those of an inactive individual. According to the International Society of Sports Nutrition, physically active individuals need between 1.4 and 2.0 grams of protein per kilogram of body weight daily.

Some people turn to protein powders and supplements to boost their protein consumption. Drinking a shake made of protein powder after a workout is sometimes more convenient than eating a meal. Among the most popular is whey protein. When you purchase whey, you might be confused by the different terms that go with it. For example, whey comes as a whey protein isolate and a whey protein concentrate. What do these terms mean?

Deciphering the Label

First, you don’t necessarily need a whey protein isolate or concentrate supplement to meet your protein requirements. Meat, dairy, and even plant-based foods contain enough protein to supply your body’s requirements. However, whey protein is a rapidly absorbed protein, meaning your digestive system breaks it down quickly, and it enters your bloodstream fast. From there it’s delivered to your muscles.

Some studies suggest there’s a window period wherein muscle protein synthesis is enhanced if your muscle cells get protein within that time frame. Originally, you may have heard that the window period is around 30 minutes to an hour. However, more recent studies suggest that it’s longer. Getting a dose of protein within a few hours still offers benefits. But when you want protein fast, whey protein is a way to get it.

Whey is also a complete protein. It contains all the essential amino acids your body needs to build new muscle proteins and repair existing ones. In addition, it contains substantial amounts of branched-chain amino acids, including leucine, a strong stimulator of muscle protein synthesis.

Where does whey come from? It’s a by-product of cheesemaking. To make cheese, cheesemakers strain cow’s milk to separate the whey and casein, another milk protein. They use the casein to make cheese and the whey is used by protein powder manufacturers.

Does whey have benefits beyond its protein content? Some studies show that whey may help with weight management, partially due to its satiety benefits. In fact, a study of 158 obese individuals found that those who consumed whey on a calorie-restricted diet lost more body fat and preserved more muscle. Other research shows it may enhance immune health in older individuals.

Forms Whey Comes In: Whey Protein Isolate and Whey Protein Concentrate

You might have heard terms like whey protein isolate and whey protein concentrate. What do these terms mean? Whether a whey powder is whey protein concentrate or whey protein isolate depends on how it’s processed. Manufacturers take certain steps to increase the protein content of whey. Once the whey has a high enough protein concentration, they can remove most of the water. What they end up with is whey protein concentrate, a powder with a protein content of around 80%.

The other processing route some manufacturers use leads to whey protein isolate. In contrast to whey protein concentrate, protein isolate contains a protein content of 90%. Therefore, whey protein isolate is a more concentrated source of protein. During manufacturing, they avoid using high heat as this could denature the proteins. Whey isolate differs from whey protein concentrate in other ways. It contains little fat or lactose, making it the ideal form of whey for people who are lactose intolerant. Whey protein concentrate can contain up to 3.5 grams of lactose per serving, while whey protein isolate contains less than 1 gram. The downside to whey protein isolate is making it requires additional steps. Therefore, the protein isolate is usually more expensive.

Is One Form of Whey Better Than the Other?

Despite a slightly higher protein content by weight, there’s no evidence that whey protein isolate offers advantages over whey protein concentrate in terms of muscle hypertrophy as long as you consume similar quantities of protein. You’ll have to consume slightly more whey protein concentrate relative to whey protein isolate to get the same protein content. However, if you’re lactose intolerant, you might choose the isolate due to the lower quantity of lactose. Also, if you’re trying to limit your fat intake, whey protein isolate is a better choice.

Do You Even Need Whey Protein Isolate or Whey Concentrate?

You can get high-quality protein from other sources. In fact, eggs rank highest in terms of protein quality. You can build muscle without using protein supplements of any type. However, whey protein is a quick way to deliver amino acids to your muscles after a workout due to its rapid absorption. Whey is high in leucine, an amino acid strongly linked with muscle protein synthesis. In fact, it’s the strongest amino acid activator of the mTOR pathway, a pathway by which muscles grow. Some studies also show that whey protein after a hard workout is beneficial for immunity. Vigorous workouts can temporarily suppress immune function and whey contains components, like lactoglobulin, lactoalbumin, and lactoferrin, that may boost it.

A downside to whey powders is that there are wide variations in quality. When ConsumerLab.com independently tested a variety of protein powders, 31% failed their quality tests. Some contained lead as a contaminant and others had higher levels of cholesterol or carbs than what was listed on the label. So, you don’t always get what you pay for and sometimes you get things you wouldn’t have expected, like lead. Plus, some people experience digestive upset when they consume whey protein.

The Bottom Line

Don’t assume you need whey protein to build muscle, but if it’s convenient for you, now you know what the pros and cons are and how whey protein isolate differs from whey concentrate. Use this information to decide what’s right for you!



·        Medical News Today. “What are the benefits and risks of whey protein?”

·        Nutr Metab (Lond). 2008; 5: 8. Published online 2008 Mar 27. doi: 10.1186/1743-7075-5-8,

·        HealthLine.com. “What’s the Difference Between Whey Isolate and Whey Concentrate?”

·        ConsumerLab.com “31% of Protein Powders and Drinks Fail Tests by ConsumerLab.com”

·        Therapy (2006) 3(1), 69-78.

·        Front Nutr. 2019; 6: 19.Published online 2019 Mar 1. doi: 10.3389/fnut.2019.00019.

·        Med Sci Sports Exerc. 2011;43:1154–61.


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