In sports nutrition it is important not only to calculate the right balance of proteins, fats and carbohydrates, but also to choose supplements adequately. This is especially true for proteins. There are so many of these supplements on the market, and it’s hard to know which one is the best to buy.
Beginning bodybuilders and athletes are often advised whey protein in two forms, concentrate and isolate. They differ not only in composition, but also in effect. So it is very important to choose the right one.
In this article we’ll look at isolate and whey protein, determining what the difference is and which is better.
Whey protein (concentrate)

Whey protein is derived from whey, the liquid component of milk. It contains quite a lot of lactose, as well as a lot of useful substances.
The production process is quite simple. Milk is first fermented and then gradually heat treated to separate the milk into two fractions, curd and whey. The liquid part includes many proteins, fats, carbohydrates, micronutrients and vitamins, in addition to water itself. That’s why it’s good on its own.
The whey is then dried. All the moisture evaporates from it, only the powder is left. This is what whey protein, or the so-called “concentrate” is. No further processing is done afterwards – the powder is mechanically homogenized, making it finely dispersed, and scattered in jars.
This is why whey protein (concentrate) contains many additional health benefits. All those vitamins, minerals, fats, and carbohydrates do not go anywhere. The concentrate contains immunoglobulins, lactoferrin, α-lactalbumin, β-lactoglobulin and other important components with high biological activity. They are all important for our health, and have a positive effect on our general well-being and are essential for a balanced diet.
Among the positive effects of consuming the concentrate are improved immunity, decreased appetite, stimulation of fat breakdown in the body, and acceleration of muscle protein synthesis. But most importantly, it reduces insulin sensitivity. This will help athletes to feel good and stay healthy even with quite strict dietary control.
Whey protein, however, is rather low in protein itself due to its high content of additional essential nutrients. Depending on the variety, it may be from 30% to 80%. In addition, the “concentrate” also contains carbohydrates, represented in the form of lactose, and this is also important to consider when formulating a proper diet.
Whey protein is also relatively slow in digestion. This is conditioned not only by the content of additional (“ballast”) additives, but also by the fact that protein in it is unprocessed. It starts to metabolize only 1 to 2 hours after intake, depending on the body’s individual characteristics.
That’s why it is recommended to take the concentrate either in the morning or a few hours before your workout. And it is important to consider the carbohydrate content. For example, two whey protein-based shakes a day yields as many “sugars” as half an apple.
In general, whey protein is characterized as follows:
Unprocessed. It contains not only essential proteins but also additional nutrients, including important and necessary for the body;
The concentration of pure protein is 30-80% depending on the manufacturer;
Includes carbohydrates, and in fairly large amounts. These nutrients are present in the form of lactose – a milk sugar;
Requires relatively slow digestion. It may take up to 2 hours after ingestion before the metabolic process begins.
Milk sugar content makes the concentrate unsuitable for people with lactose intolerance. This is very important to consider when choosing, because carbohydrates can be up to 30-50% of the weight of the product.
So let’s summarize.
Advantages
Additional useful substances in the composition nourish the body, strengthen the immune system, reduces the sensitivity to insulin;
Does not need to be processed additionally. Therefore, it does not contain any ballast harmful additives;
Good for nourishing the body throughout the day when taken in the morning. Gradual saturation of the body with protein also helps reduce catabolic processes that lead to destruction of muscle tissue and muscle pain.
Disadvantages
The concentration of the protein itself may be quite low. The best versions of the concentrate have it up to 80% of weight, while the worst ones have 30%;
Its slow digestion makes it unsuitable for ingestion after workouts. It is required to drink it either in the morning or 1-2 hours before sports activities.
It’s also worth noting that whey protein concentrate is low in price. This can be quite important for athletes who aren’t willing to spend large sums of money on supplements.
Isolate

Isolate is processed whey protein. After the liquid fraction is evaporated from the raw material, the concentrate is further purified. Therefore, its protein fractions begin to degrade and break down into compounds that are easier to digest.
Basically, the same processes take place in the production of the isolate as in the digestion of the concentrate. Only they are not carried out in the intestines but in special purification machines. Whey protein isolate ends up being very easy to digest, but retains its anabolic properties.
During processing (denaturation) the sequence of amino acids in the protein is preserved. This is why it also helps in building muscle, improving anabolic processes and worsening catabolic ones.
However, it is important to note that the isolate is not biologically active. Virtually all of the useful additives are removed during production. Ready-to-cook powder contains up to 99% pure protein in an easily digestible form.
In general, the isolate is characterized as follows:
Treated. Contains denatured proteins in an easily digestible form. No additional substances, either beneficial or harmful. Except that trace amounts may remain that do not affect anything;
Pure protein concentration ranges from 90% to 99% depending on the manufacturer and processing method. For example, isolate obtained by cross-microfiltration consists of 90% pure protein and the rest is healthy nutrients. Up to 99% by ion exchange;
Contains no carbohydrates or lactose;
Begins to be absorbed almost immediately after ingestion – usually in about 10-20 minutes. That’s why it is perfectly suited for use at the end of a training session.
Since there is no dairy sugar in the isolate, it is suitable for people with lactose intolerance. But beware, some manufacturers do not refine it well enough. Low-quality isolate may therefore contain trace amounts of lactose.
So, let’s summarize.
Advantages
Contains pure protein and nothing else. The protein in it is presented in an easily digestible form and therefore begins to be metabolized by the body shortly after ingestion;
Suitable for use immediately after training to improve muscle growth and development and slow down muscle breakdown.
Disadvantages
Does not contain beneficial and biologically active substances;
Relatively high price.
Isolate from cross-flow microfiltration or other microfiltration technologies may be an option, given a reasonable budget. Offers more nutrients than ion exchange-treated. The nutritional value of microfiltered isolate is comparable to that of concentrate.
Comparison and which is better

Whey protein (concentrate) has more benefits, but its effect is slow, while isolate is a pure protein and is absorbed immediately after ingestion. But that’s not the only difference between the two supplements.
Characteristics | Whey protein | Isolate |
Protein content | 30-80% | 90-99% |
Supplemental benefits | Immunoglobulins, lactoferrin, α-lactalbumin, β-lactoglobulin, and more | Trace amounts |
Carbohydrate content | Up to 30-50%, in the form of lactose | Trace amounts |
Effect | Anabolic, catabolic inhibitor, immunostimulant, improves insulin resistance | Anabolic, catabolic inhibitor |
Metabolism | Relatively slow (begins 1-2 hours after ingestion) | Relatively fast (starts 10-20 minutes after taking it) |
Price | Relatively low | Relatively high |
The concentrate is better overall. It contains additional nutrients and has a positive effect on the body. It’s also inexpensive. However, it metabolizes slowly, so it is not suitable for use after working out.
Isolate metabolizes quickly, but it is a pure protein. Therefore, it is necessary to saturate your body with additional nutrients.
If you don’t have any money, you can try isolate, which is produced by microfiltration. It is expensive, but it contains many important compounds, metabolizes quickly, and is made almost entirely of protein.