Best whey protein isolate

It doesn't get much better than whey protein isolate when it comes to building more muscle mass, improving recovery times, and optimizing athletic performance. With dozens of different protein powders on the market, it can be challenging to know which one is the best to help you power your performance and meet your goals. In this guide, we'll teach you all things whey protein isolate, so you can make the choice, on what protein powder is truly the best for you. 

In this ultimate guide to Whey Protein Isolate, we will cover the following topics

  • What Is Whey Protein Isolate?
  • How Does Whey Protein Isolate Work?
  • How Is Whey Protein Isolate Made?
  • What Are The Benefits Of Whey Protein Isolate?
  • What’s The Difference Between Whey Isolate And Whey Protein?
  • What’s The Difference Between Whey Isolate And Casein?
  • What’s The Difference Between Whey Isolate And Pea Protein?
  • How Much Whey Protein Isolate Should I Take?
  • What Is The Best Whey Protein Isolate Supplement?

What Is Whey Protein Isolate? 

To understand whey protein isolate, you first have to understand what ordinary whey protein or whey concentrate is. Whey protein is a complete source of high-quality protein derived from cow's milk, containing a complete amino acid profile.  Whey protein has a very high concentration of the essential amino acids, responsible for building and rebuilding lean muscle mass called the branched-chain amino acids (BCAAs). BCAAs are comprised of leucine, isoleucine, and valine Studies have shown that the branched-chain amino acids, especially leucine is responsible for enhancing skeletal muscle and mass. 

RELATED ARTICLE What Are The Benefits Of BCAAs?

Whey protein isolate is a highly purified form of Whey protein. Whey protein isolate goes through a rigorous filtration process, called Cross-Flow Micro-Filtration. Through this filtration process, protein is separated from any additional fat, carbohydrates, cholesterol, and lactose, resulting in a more purified form of protein. Whey protein isolate is therefore a more refined form of protein, without any extra macronutrients. This is especially great, if one of your goals, is to optimize body composition, and burn more body fat, since it contains fewer calories, fat, carbohydrates, and sugar than any other type of whey protein, or casein.

How Does Whey Protein Isolate Work? 

Like all protein, whey protein isolate is comprised of amino acids. Protein is primarily used for building muscle mass and rebuilding and repairing muscle mass breakdown. This is why consuming protein after training is crucial to maximize performance benefits and gains, by repairing lean muscle mass and optimizing recovery time. Numerous studies have demonstrated that protein supplementation or ingestion post-workout has a beneficial effect on acute anaerobic power, strength, and recovery [R].

How Is Whey Protein Isolate Made?

High-quality milk is the first step in creating a high-quality whey or whey protein isolate. Swolverine’s whey protein isolate, is made from the happiest grass-fed cows in America, free of rBGH [recombinant growth hormone], and delivers 26g of pure protein per serving. The milk is which is used in the cheese manufacturing process, is separated into curds and whey. The curds move on and live their destiny to become cheese, while the way moves one step closer to filling your shaker cup. Liquid whey is immediately loaded then taken to be manufactured into protein. The whey is then pasteurized and filtered. It takes 720 pounds of liquid whey, just to get one five-pound container of whey protein. Through a crossflow cold micro-filtration process, the liquid whey is separated from the fat, carbohydrates, and lactose, while retaining important amino acids and micronutrients. The last step of the process, is pumping the refined liquid into a dryer mixed with hot and cold air, leaving you with a 90% pure whey protein isolate powder. 

What Are The Benefits Of Whey Protein Isolate?

1. Whey Protein Isolate Benefits: Builds Lean Muscle Mass

Whey Protein Isolate is rich in the essential Branched Chain Amino Acids (Leucine, isoleucine, and Valine), which are directly responsible for increasing the rate of muscle protein synthesis the biological process of building muscle and decreasing the rate of protein degradation. BCAAs are the essential building blocks of protein. Whether you love lifting weights, or crushing times during your WOD, your body utilizes amino acids for fuel which increases the rate of protein breakdown and amino acid oxidation. When you workout, BCAAs are expended quickly, and without a positive balance of BCAAs, the rate of protein breakdown will be greater than the rate of protein synthesis, meaning you’ll actually lose muscle mass, rather than gain it. 

RELATED ARTICLE Do BCAAs Really Work? And What Do BCAAs Do?

In a study published in the Journal Of International Society of Sports Nutrition, thirty college-aged male and female subjects were administered 46g of Whey Protein Isolate immediately the following exercise for a period of 8 weeks. According to Dual emission, x-ray absorptiometry (DXA) used to determine changes in body composition and maximum strength assessed by one-rep-max (1RM) for bench press (upper body) and deadlift (lower body) the results were astounding. Lean body mass increased by 4.7%, with an 8.3% decrease in body fat, coupled with a 19.3% increase in the bench press, and 17.6% increase in deadlift max [R]. If you want to build lean muscle mass, then you should probably get some Whey Protein Isolate. Gains!

RELATED ARTICLE Post Workout Nutrition: What Should You Eat Ater Your Workout?

2. Whey Protein Isolate Benefits: Burns Body Fat 

Supplementing with a protein shake containing whey protein isolate, will always contain fewer calories, fat, carbohydrates, and sugar than any other type of whey protein, casein, or plant protein. Drinking a liquid form of protein, will provide the vital nutrients you need, to further optimize body composition and deliver the nutrients you need. Protein also helps with satiation (keeping you full) and will help you hit your daily protein intake. 

RELATED ARTICLE Post-Workout Nutrition: What You Should Eat After Your Workout For The Best Results 

In a randomized, controlled, double-blinded trial, published by the Journal Of International Society of Sports Nutrition, 86 male subjects were given 30g of Whey protein isolate immediately following resistance training, for a period 12 weeks. The subjects were randomized into three groups. One group received Whey protein isolate, one group carbohydrates maltodextrin, and one group Whey protein isolate + carbs.

The results showed that supplementing with Whey protein isolate, increased abdominal fat loss and relative fat-free mass adaptations in response to resistance training when compared to fast-acting carbohydrates. Therefore, if your main goal is to maximize fat loss responses to your training program, especially from the abdominal area without compromising increases in lean muscle mass, whey protein isolate instead of fast-acting carbohydrates like maltodextrin are recommended for post-exercise nutrition [R]. If your goal is weight loss, muscle gain, and optimized body composition, try some of these carbohydrate sources.

RELATED ARTICLE 6 Incredible Clean Carb Sources To Build Muscle Mass And Improve Body Composition

3. Whey Protein Isolate Benefits: Increases Strength

Whey Protein Isolate contains a higher content of BCAAs, primarily Leucine, compared to any other protein source. Leucine is the essential amino acid, that signals muscle protein synthesis to occur. In other words, Leucine has more muscle-building capabilities than most other amino acids. And with a rapid digestion rate, whey protein isolate increases blood amino acid concentrations shortly after ingestion. Several studies indicate that Whey Protein Isolate stimulates muscle protein synthesis better than any other protein source, building more lean muscle mass, equating to building greater gains in strength [R].

4. Whey Protein Isolate Benefits: Enhances Muscle Recovery

Ensuring quick and efficient muscle recovery is one of the most important components to optimizing your training. If you can actively recover faster, then you can increase your training volume, which translates into better athletic performance and better results. Supplementing with Whey Protein Isolate before, during, or after your training, stimulates protein synthesis and minimizes protein breakdown (proteolysis), which are the two biological processes that are essential for exercised induced muscle recovery. Compared to regular protein supplements, whey protein isolate is more effective at increasing blood amino acids and protein synthesis due to its different absorption kinetics and amino acid profile. The high availability of amino acids in whey protein isolate, especially branched-chain amino acids, is important for protein synthesis in the hours immediately after ingestion [R]. Whey protein isolate also contains high amounts of L-Glutamine, which is a conditionally essential amino acid, which helps decrease muscle mass breakdown, and exercise-induced muscle soreness.

RELATED ARTICLE L-Glutamine: The Best Supplement For Post-Workout Recovery And Soreness 

5. Whey Protein Isolate Benefits: Reduces Hunger

Diets higher in protein are typically correlated with sustained satiety. The hierarchy for macronutrient satiety, is similar to that observed for diet-induced thermogenesis. Protein is the most satiating macronutrient, followed by carbohydrates and fat, which are the least filling. Whey protein isolate provokes the strongest reduction in hunger followed by Casein and Soy. Decreased hunger rates coincide directly with higher leucine, lysine, tryptophan, isoleucine, and threonine response, which makes Whey Isolate the best protein source to increase satiety [R] With increased fullness, you can focus on hitting your macronutrient intake and performance goals.

RELATED ARTICLE The Ultimate Guide To Macronutrients

What’s The Difference Between Whey Isolate And Whey Protein Concentrate?

Whey protein and whey protein isolate are both derived from the same milk concentration. The main difference between them is that whey protein isolate has been put through a cold-filtered crossflow micro-filtration process to help remove the lactose, carbs, and fat in order to derive a highly purified and refined form of protein. Both forms of whey are known as complete proteins, and contain all 9 essential amino acids, to help build and rebuild lean muscle mass while optimizing post-workout muscle recovery. Since these amino acids are essential, they must be obtained through diet or through supplementation. 

Whey Concentrate Vs Whey Isolate Key Differences 

  • Whey isolate contains a higher protein content, ranging around 90% purity compared to whey concentrate, at 70-80% protein purity.
  • Whey protein isolate contains less than 1% lactose and milk fat, as compared to whey protein concentrate, which contains over 50% lactose per serving, and over 2% fat per serving.
  • Whey protein concentrate can cause bloating, due to the lactose and carbohydrate content.
  • Whey protein isolate has a lower calorie count as compared to whey protein concentrate
  • Whey protein isolate absorbs faster, which makes it an ideal post-workout supplement to help with crucial amino-acid delivery.

The table below shows the key differences between a standard whey isolate and whey concentrate supplement per 100-calorie serving

RELATED ARTICLE Whey Vs Whey Isolate: Which One Is Better?

At Swolverine we always choose whey protein isolate, as you get more protein per serving, without the lactose and bloating.

What’s The Difference Between Whey Isolate And Casein?

Casein protein is also found and derived from milk. When a coagulant is added to milk, the whey and the casein separate, leaving two distinct forms of protein. Casein protein has a much thicker consistency and moves through the gastrointestinal tract more slowly providing a long-sustained release of amino acids also referred to as the ‘amino-acid drip’. This is why casein is marketed to be consumed before bed, so that you can get an overnight supply of amino acids, to increase the anabolic process of muscle protein synthesis and build more muscle mass and strength [R

RELATED ARTICLE Should You Drink Protein Before Bed?

A single glass of milk contains around 80% casein and 20% whey. If you were to let milk coagulate, casein would be the curd, while whey would be the liquid. This should give you an idea of the differences between how whey and casein are absorbed, which leads us into the main difference between whey and casein – absorption rate.

The biggest difference between whey isolate vs. casein protein is the absorption rate. Casein and Whey are both very rich sources of protein and essential amino acids, which help build and rebuild lean muscle mass.

whey vs casein

According to a study, which examined the differences between whey vs. casein pre and post-workout, the results indicated that there were no significant differences between whey vs. casein in regard to performance. Both groups experienced significant improvements in body composition, strength, and anaerobic performance when consuming either protein supplement pre- and post-exercise. However, no significant effects were observed between groups in changes in any variable [R].

Casein Vs Whey Isolate Key Differences 

  • Both increased Strength
  • Both Build Lean Muscle mass
  • Both Repair Muscle Tissue For Faster Recovery
  • Both are also rich in amino acids and are derived from milk
  • The biggest difference is the absorption rate

Which One Is Better Whey Vs. Casein?

Although both whey isolate and casein protein are derived from dairy and have a high amino acid content, whey isolate is considered to be more anabolic due to its rapid digestion rate. Yet despite this fact, studies suggest that even though whey initiates muscle protein synthesis faster than casein, there is no difference between performance indicators.

RELATED ARTICLE Whey Vs. Casein: Which One Is Better?

What’s The Difference Between Whey Isolate And Pea Protein?

Peas have proven to be a powerful little green bean full of protein. But, is pea protein actually better than whey? Studies have shown, that compared to other plant-based protein sources, peas have the most similar amino acid profile to whey protein, and even similar benefits in regard to athletic performance and building lean muscle mass. 

Although animal-based protein sources such as whey, casein, and egg are highly effective at improving athletic performance goals, pea protein has also proven to deliver anabolic benefits. Specifically, pea protein is just as effective in stimulating muscle protein synthesis and providing other valuable attributes such as efficient and quick digestibility in addition to providing valuable micronutrients. Peas also have a full essential amino acid (EAA) profile, which is critical in the muscle-building process. As compared to other plant-based protein sources, Pea protein has the highest essential amino acid mix, almost rivaling that of Whey Protein [R].

RELATED ARTICLE Pea VS Whey: What Are The Differences?

In a double-blind randomized controlled study published in the Journal Of The International Society Of Sports Nutrition, pea protein went head to head against whey protein, to investigate the effects on muscle composition and strength. 161 male participants enrolled in a 12-week resistance training program and were randomized into a pea, whey, and placebo control group. The results showed a significant and greater effect on muscle composition amongst the pea protein group, with no clinical difference between groups in regard to muscle strength. Therefore, this study proves, that Pea protein, is a phenomenal plant-based protein source to help increase muscle strength and composition, to further improve athletic performance [R].

A similar study conducted at Lipscomb University in Tennessee, compared the effects of whey and pea protein supplementation in conjunction with 8-weeks of High-Intensity Functional Training (HIFT) on strength, body composition, muscle thickness, IMTP peak force, IMTP RFD, and WOD performance. The results confirmed that whey and pea proteins promote similar strength, performance, body composition, and muscular adaptations following 8-weeks of HIFT [R]. 


Part of the argument, in plant-based protein vs animal-based protein is amino acid mix. By having a full amino acid profile, you’ll get the essential nutrients you need to increase muscle mass and remain in an anabolic state. Pea protein has a very similar amino acid mix, as compared to whey. Due to its high amount of essential amino acids, specifically arginine, leucine, isoleucine, valine, and alanine (leucine, isoleucine, and valine are the branched chain amino acids BCAAs, and are known to be most responsible for stimulating muscle protein synthesis), pea protein is an amazing plant-based protein alternative for athletes. Arginine specifically helps facilitate the release of nitric oxide, which increases oxygen and blood flow, translating to increased muscle growth, and better recovery. Pea Protein has nearly three times the amount of arginine than whey protein. No, I’m not kidding. Just look at the reference comparison table below.

Amino acid composition in g/100 g of whey and pea protein supplements.

Amino Acid

Whey Protein

Pea Protein







Aspartic Acid






Glutamic Acid











































Whey Protein Isolate Vs Pea Protein Key Differences

  • Whey protein and pea have similar anabolic and performance benefits
  • Whey protein isolate and pea protein have a similar and complete amino acid profile.
  • Pea protein has a better micronutrient profile. Pea protein is rich in iron, manganese, folate, copper, phosphorus, vitamins B6, B2, niacin, molybdenum, fiber, and vitamins A, C, and K.
  • Whey protein isolate taste better than pea protein, always and forever.
  • Although pea protein absorbs faster than all other plant-based protein. whey protein isolate absorbs faster, which makes it an ideal post-workout supplement to help with crucial amino-acid delivery.

How Much Whey Protein Isolate Should I Take?

Best whey protein isolate

The amount of protein you ingest on a daily basis varies based upon several factors such as activity level, age, sex, height, weight, athletic goals, etc. However, the minimum recommended daily amount of protein intake to meet basic nutrition requirements is 0.37 grams per pound of body weight (or 0.8 grams per kilogram of body weight) if you’re using the metric system. According to the FDA, the daily value for protein is 50 grams based on a 2,000 calorie diet.

Remember when I said the amount of protein you need, depends on several factors? One of those factors is athletic goals. If your goal is to maximize your gym efforts, by building more muscle and increasing strength gains, then your protein requirements, and macronutrient requirements, in general, are going to increase. Most people don’t need to supplement with protein powder, considering activity level, and the amount of protein they get from their diet. But, if you’re trying to enhance your athletic performance, you’re going to need more than the recommended daily amount to max out your gains. That’s why it’s extremely beneficial to supplement with protein powder, pre or post-workout.

According to the American College of Sports Medicine, the optimal daily protein intake is 0.5-0.9 grams of protein per pound of bodyweight. Other sources, say physically active individuals that are optimizing training performance protein need at least 1.4–1.6 g/kg/day of protein [R].  If you’re not sure how much protein you really need, follow the table below, or better yet hire a certified nutrition coach from The Swole Kitchen to help get you to your goals without the hassle.


Weight in lbs.

Minimum Protein

Athletes Minimum


37 grams

74 grams


40 grams

80 grams


44 grams

88 grams


47 grams

94 grams


51 grams

102 grams


55 grams

110 grams


58 grams

116 grams


62 grams

124 grams


65 grams

130 grams


69 grams

138 grams


72 grams

144 grams


76 grams

152 grams


80 grams

160 grams


84 grams

168 grams


87 grams

174 grams


91 grams

182 grams


95 grams

190 grams


98 grams

196 grams


102 grams

204 grams


105 grams

210 grams


109 grams

218 grams


What Is The Best Whey Protein Isolate Supplement?

best whey protein isolate  

Swolverine’s Whey Protein Isolate is the best whey protein supplement. Each flavor Honey Cinnamon Peanut Butter, Chocolate, and Vanilla contains 26 grams of ultra-pure, cold-pressed, rich and creamy, micro-filtered Whey Protein Isolate per serving.* Sourced from the happiest cows in America, free of rBGH (recombinant bovine growth hormone), Swolverine’s Whey Protein Isolate is loaded with the building blocks you need to build your athletic performance and strength.* Each scoop contains added digestive enzymes (Papain & Protease) to maximize the rate of absorption, which is key to optimizing muscle growth and post-workout recovery. We’ll turn your post-workout shake into the most exciting part of your workout!

How To Pick A Protein Powder 

The most important part when deciding on what protein powder to buy is making sure it’s transparent, proprietary-blend free, and third-party tested. Make sure the manufacturer discloses the amounts of each ingredient and does not use a blend, so you know exactly what and how much of each ingredient you’re getting.

Next, pay attention to the other ingredients. Some protein powders will have dozens of ingredients and hidden sweeteners, such as dextrose, high-fructose corn syrup, and fillers. Sucralose, stevia, and monk fruit extract are all acceptable sweeteners, as they are recognized as GRAS (generally recognized as safe) ingredients by the FDA and have not shown any adverse effects through human toxicology reports. Despite the bad press, sucralose also does not have any negative effect on gut health.

Lastly, make sure the protein you’re buying has a high amount of protein per serving. Simply take the amount of protein in each serving and divide it by the grams per serving. This will give you an accurate number of how pure your protein really has. Look for 85-92% purity. Most quality protein powders will also add digestive enzymes, such as papain, protease, or pro hydrolase for better nutrient absorption. Swolverine has 26g of pure protein per 30g serving, which puts it at 90% purity. 

Trying To Decide If You Need More Protein In Your Diet?

 SWOLVERINE's Whey Protein Isolate is made from the happiest grass-fed cows in America, free of rBGH. With 26 gams of pure, cold-pressed and delicious whey isolate per serving, you'll get the ingredients you need to power your performance and optimize your recovery. <

SWOLVERINE is an endurance athlete and active lifestyle brand. Made for the elite athlete, and the strong-willed our products were designed to fuel your athletic performance. We perform when you perform. 

We believe that everyone can optimize not only their athletic performance but their human potential. The way we believe we can optimize performance is through transparency, clinically effective doses, and clinically proven ingredients with evidence-based outcomes. We provide the nutrients you need to power your active lifestyle. 


  • Joy, Jordan M et al. “Daytime and nighttime casein supplements similarly increase muscle size and strength in response to resistance training earlier in the day: a preliminary investigation.” Journal of the International Society of Sports Nutrition 15,1 24. 15 May. 2018, doi:10.1186/s12970-018-0228-9
  • Volek JS, Volk BM, Gómez AL, et al. Whey protein supplementation during resistance training augments lean body mass. J Am Coll Nutr. 2013;32(2):122-35.
  • Wilborn, Colin D et al. “The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes.” Journal of sports science & medicine 12,1 74-9. 1 Mar. 2013
  • Wolfe, R. R. (2001). Control of muscle protein breakdown: effects of activity and nutritional statesInternational Journal of Sport Nutrition and Exercise Metabolism, 11(s1), S164-S169.
  • Miller, S. L., Tipton, K. D., Chinkes, D. L., Wolf, S. E., & Wolfe, R. R. (2003). Independent and combined effects of amino acids and glucose after resistance exerciseMedicine & Science in Sports & Exercise, 35(3), 449-455.
  • Dangin, M., Boirie, Y., Garcia-Rodenas, C., Gachon, P., Fauquant, J., Callier, P., ... & Beaufrère, B. (2001). The digestion rate of protein is an independent regulating factor of postprandial protein retentionAmerican Journal of Physiology-Endocrinology And Metabolism, 280(2), E340-E348.
  • Tipton, K. D., Elliott, T. A., Cree, M. G., Wolf, S. E., Sanford, A. P., & Wolfe, R. R. (2004). Ingestion of casein and whey proteins result in muscle anabolism after resistance exerciseMedicine & Science in Sports & Exercise, 36(12), 2073-2081.
  • Sharp, Matthew et al. “The Effects of Beef Protein Isolate and Whey Protein Isolate Supplementation on Lean Mass and Strength in Resistance Trained Individuals - a Double-Blind, Placebo-Controlled Study.” Journal of the International Society of Sports NutritionSuppl 1 (2015): P11. PMC. Web. 23 Sept. 2017.
  • Hulmi, Juha J. et al. “The Effects of Whey Protein with or without Carbohydrates on Resistance Training Adaptations.” Journal of the International Society of Sports Nutrition12 (2015): 48. PMC. Web. 23 Sept. 2017.
  • Cooke, Matthew B, et al. “Whey protein isolate attenuates strength decline after eccentrically-induced muscle damage in healthy individuals.” Journal of the International Society of Sports Nutrition, BioMed Central, 22 Sept. 2010, Accessed 23 Sept. 2017.
  • Jäger, Ralf et al. “Comparison of Rice and Whey Protein Isolate Digestion Rate and Amino Acid Absorption.” Journal of the International Society of Sports NutritionSuppl 1 (2013): P12. PMC. Web. 24 Sept. 2017. [Pub Med]
  • Pesta, Dominik H, and Varman T Samuel. “A High-Protein Diet for Reducing Body Fat: Mechanisms and Possible Caveats.” Nutrition & Metabolism11 (2014): 53. PMC. Web. 24 Sept. 2017.
GuidesNutritionProteinSupplementsWhey protein isolate

Featured products

8 reviews
8 reviews
8 reviews

Join Over 1,000,000 Fans

Get exclusive access to discounts and the latest on fitness, nutrition, and wellness delivered straight to your inbox

Free domestic shipping

Free shipping on domestic orders over $99

Free Content & Exclusive Sales

Join our email list and receive member-exclusive promos

Top-notch support

We're committed to an amazing customer experience

Secure payments

Your payment information is encrypted and never compromised