Shifted whey protein isolate next to 30lb dumbbells on a gray concrete table outside

The Best Whey Protein Isolate Powders (Our 2024 Review)

You might miss some major benefits if you’re “just” working out. An easy (and tasty) way to rev up your body’s ability to build muscle faster is by taking protein drinks made with 100% whey protein isolate (WPI).

The best whey protein isolate powders can help you build lean muscle faster, manage your weight, recover from intense workouts more effectively, and minimize muscle soreness. 

Table of Contents

Best Whey Protein Isolates

There’s no shortage of options when it comes to whey protein isolate supplements. We’ve reviewed some of the best ones available today, but if you want our quick recommendation, our top choice is SHIFTED Whey Protein Isolate. It has 25 grams of protein per serving, helps build muscle mass fast, and it tastes good.

Brand
Best Overall
SHIFTED Whey Protein Powder
Best Grass Fed
Transparent Labs Whey Protein Isolate
Best Flavor Selections
Kaged Whey Protein Isolate
Product
SHIFTED Whey Protein Powder, 100% Pure Whey...
Transparent Labs Grass-Fed Whey Protein Isolate -...
Kaged Whey Protein Isolate Powder | Vanilla | 100%...
Protein/ Serving (grams)
25g
28g
25g
Taste
100/100
95/100
93/100
Best Overall
Brand
SHIFTED Whey Protein Powder
Product
SHIFTED Whey Protein Powder, 100% Pure Whey...
Protein/ Serving (grams)
25g
Taste
100/100
Price
Best Grass Fed
Brand
Transparent Labs Whey Protein Isolate
Product
Transparent Labs Grass-Fed Whey Protein Isolate -...
Protein/ Serving (grams)
28g
Taste
95/100
Price
Best Flavor Selections
Brand
Kaged Whey Protein Isolate
Product
Kaged Whey Protein Isolate Powder | Vanilla | 100%...
Protein/ Serving (grams)
25g
Taste
93/100
Price

SHIFTED Whey Protein Isolate

  • Ingredient Quality: 100/100
  • Overall Rave Score: 98.3

SHIFTED is a relative newcomer to the supplement industry, but the brand’s commitment to quality ingredients and cutting-edge, science-backed formulations make it well worth watching. 

SHIFTED Whey Protein Powder, 100% Pure Whey...

Made with serious athletes and exercise enthusiasts in mind, SHIFTED Whey Protein Isolate is our favorite whey protein isolate product on the market right now. It’s the ideal WPI powder supplement for building muscle mass fast, minimizing post-workout soreness, and enhancing recovery after even the most intense exercise.

With an amino acid profile that includes 12 grams of essential amino acids and 5.5 grams of branched-chain amino acids, the supplement contains optimal dosages of every amino acid you need to maximize your muscle gains. 

A single serving provides 25 grams of fast-digesting complete protein to help your body start building and restoring muscle right away. If you struggle to eat enough protein to meet your fitness goals, this one’s for you—providing 50% of the percent daily value of protein in a single scoop.

We love that SHIFTED Whey Protein Isolate contains just 0.5 g of sugar and no added sugars. Each scoop includes only 2 g of carbohydrates, 1 g of total fat, and 146 mg of sodium. A single scoop is only 110 calories and provides calcium (120 mg), iron (100 mcg), and potassium (160 mg) to help your body thrive. 

It also includes 2% of your recommended daily fiber intake. There are no proprietary blends, and the formulation is naturally gluten-free. This 100% whey protein isolate powder has everything you want from a protein supplement and nothing you don’t.

Users love the “delicious” taste of SHIFTED’s two flavors of WPI powder, Chocolate Milk and Cookies and Cream. The company’s goal was to produce “a whey protein that tastes as good as it works,” so it’s no wonder users have called SHIFTED Whey Protein Isolate “the BEST tasting whey protein” they’ve tried. 

Both flavors are rich, silky, and reminiscent of a milkshake or dessert. While the Chocolate Milk flavor tastes like creamy fudge, the Cookies and Cream flavor is reminiscent of rich vanilla ice cream blended with chocolate chip cookie crumbles.

Shifted whey protein isolate next to 30lb dumbbells on a gray concrete table outside

SHIFTED Whey Protein Isolate 100% WPI is a premium product sold at a competitive price point. See the full review here!

But, don’t just take it from us. We connected with Jason Cage, who’s been a personal trainer and gym instructor for over a decade, and he shared that SHIFTED Whey Protein Powder is his go-to option, and here’s why:

“There is more to recovery than protein alone. This is why Shifted Whey Protein Isolate is my go-to protein powder. It contains not only optimal protein for recovery from your workouts but also BCAA’s and EAA’s.

If that doesn’t mean anything to you, don’t worry, I’ll explain. 

BCAA’s (Or Branch Chain Amino Acids) are essential amino acids that the body can not create on its own. Often, you would take them in supplement form, but as they are already present in SHIFTED Whey Protein, you don’t have to worry about it.

BCAA’s can assist with improved performance in the gym and less recovery time. This is vital as the quicker you recover, the greater your results.

EAAs (Or Essential Amino Acids) are also vital for protein to work optimally. Unlike BCAA’s, they are often found in good nutritious food. However, having them in powder form makes things much easier to stay consistent and receive all the muscle-building and recovery benefits from your protein consumption.”

Pros

  • 25 g of protein per serving
  • A science-backed formulation 
  • An impressive amino acid profile with 12 g of essential amino acids and 5.5 g of branched-chain amino acids
  • Very low levels of fats and carbs
  • Rich, delicious flavors that users have praised as “the best” 
  • A competitive price for a premium WPI product

Cons

  • Fewer flavor options compared to brands like Kaged and Transparent Labs 
  • Not third-party laboratory tested, as some competitors are
SHIFTED Whey Protein Powder, 100% Pure Whey...
  • SUPERIOR PROTEIN POWDER: SHIFTED's premium protein formula is made up of 100% Whey Protein Isolate,...
  • DELICIOUSLY FLAVORED PROTEIN POWDER: SHIFTED's Whey Protein fuels your muscles and satisfies your...
  • HIGH PROTEIN POWDER: SHIFTED's Protein Isolate is packed with 25g of high-quality and easily...

Transparent Labs Grass-Fed Whey Isolate

  • Ingredient Quality: 90/100
  • Overall Rave Score: 93.3

The Grass-Fed Whey Isolate supplement by Transparent Labs is consistently a top performer on the WPI powder supplement market. We especially recommend this one if you’re picky about where your animal products come from because the whey is sourced exclusively from grass-fed, hormone-free cows in the U.S.

Transparent Labs Grass-Fed Whey Protein Isolate -...

This entry in Transparent Labs’ ProteinSeries includes 28 g of protein per scoop. With 0 g of total fat and sugar, less than 1 g of carbohydrates, and 160 mg of sodium, you won’t find many products on the market that outperform Transparent Labs Grass-Fed Whey Isolate. The formulation also includes 134 mg of calcium, 0.5 mg of iron, and 130 mg of potassium, per the current nutrition facts label.

The company emphasizes “clean” protein, and its formulation reflects that priority with no artificial sweeteners, dyes, or preservatives. It’s also gluten-free.

We love that the versatile formulation is suitable for bulking up with lean muscle mass or for losing weight by replacing existing fat with muscle, so the supplement appeals to a wide audience.

Transparent Labs offers eight tasty flavors of its WPI supplement:

  • Chocolate Peanut Butter
  • Cinnamon French Toast
  • French Vanilla
  • Milk Chocolate
  • Mocha
  • Oatmeal Chocolate Chip Cookie
  • Strawberry
  • Vanilla Peanut Butter

Users genuinely enjoy the taste of this supplement. Flavors like Mocha, French Vanilla, and Cinnamon French Toast are particularly popular.

Transparent Labs Grass-Fed Whey Isolate offers a value on par with other top-tier WPI powder supplements. Regular users should consider a subscription that would save them about 10% each month.

Transparent Labs whey protein isolate container next to a protein shake on a gray gym floor

The biggest complaint users have about the Grass-Fed Whey Isolate supplement by Transparent Labs is availability. Consumers like the option to shop around for the best deals and the convenience of purchasing supplements through trusted retailers. It’s hard to find it sold on multiple sites, and it goes out of stock a decent amount. 

This inconvenience and unreliable availability can be a big issue when you consistently depend on a product to be part of your fitness routine.

Pros

  • The highest dose (28 g) of protein per serving
  • Whey is domestically sourced from grass-fed, hormone-free cows
  • 0 g of sugar
  • 0 g of fat
  • Plenty of flavors to choose from
  • A competitive price for a premium WPI product

Cons

  • Limited availability
  • Not third-party laboratory tested, as some competitors are
Transparent Labs Grass-Fed Whey Protein Isolate -...
  • Naturally Flavored Clean Protein Powder: Made from naturally-fed, hormone-free whey, free of...
  • 28g of Protein Per Serving: Transparent Labs Whey Protein Isolate is sourced from 100% grass-fed,...
  • Enhance Recovery, Increase Strength: Transparent Labs 100% Grass-Fed Whey Protein Isolate gives you...

Kaged Whey Protein Isolate

  • Ingredient Quality: 90/100
  • Overall Rave Score: 93.3

The most affordable supplement on our list is Kaged Whey Protein Isolate, with a budget-friendly price. The per-container cost is high, but you get 44 servings in the 3-pound container.

Kaged Whey Protein Isolate Powder | PB Chocolate |...

Despite the cost savings, you get a full dose of 25 g of protein in each 31 g scoop. We love that the pure whey protein isolate product includes 12 g of essential amino acids—and 6 g of branched-chain amino acids—per serving in the formulation.

With 0 g of fat, 0 g of sugar, and 0 mg of cholesterol, this supplement delivers on its protein promise without ingredients that can wreck your diet plans. Kaged Whey Protein Isolate contains just 2 g of carbohydrates. You’ll also find 150 mg of sodium in each scoop, along with 124 mg of calcium and 159 mg of potassium. The supplement is gluten-free and devoid of artificial colors and flavors.

In addition to the widely available flavors of Chocolate and Vanilla, Kaged makes its Whey Protein Isolate powder in flavors of S’mores, Chocolate Peanut Butter, and Cinnamon French Toast. 

The manufacturer describes its flavors as tasting “like your favorite ice cream shake,” and users tend to agree. Vanilla and Chocolate Peanut Butter are among the more popular flavors of the supplement. Some users, however, feel that Kaged Whey Protein Isolate tastes slightly too sweet for their liking.

Man in a red shirt holding a large container of Kaged protein powder in a living room

Two aspects of the formulation really make Kaged Whey Protein Isolate special. For one thing, the formulation includes a patented digestive enzyme blend, ProHydrolase, that helps the body quickly break down protein. We also love that the product is third-party tested and has earned recognition as Banned Substance Free by Informed Sport.

Pros

  • 25 g of protein
  • 0 g of sugar, fat, and cholesterol
  • Includes ProHydrolase patented enzyme to improve the digestion of protein
  • Plenty of flavors to choose from
  • Third-party tested and recognized as Banned Substance Free by Informed Sport
  • Budget-friendly

Cons

  • More sugar than SHIFTED Whey Protein Isolate and Thorne Whey Protein Isolate
  • Too sweet for some users 
  • Compared to SHIFTED Whey Protein Isolate, Kaged Whey Protein Isolate is missing dietary fiber
Kaged Whey Protein Isolate Powder | PB Chocolate |...
  • BUILD MORE : Whey Protein Isolate powder delivers 25g of whey protein per serving. Withfull-spectrum...
  • FORMULATED FOR ENHANCED ABSORPTION: Our advanced whey isolate protein powder utilizes ProHydrolase,...
  • GOLD-STANDARD PROTEIN PURITY & QUALITY: Every batch is cold-processed, then purified using...

Optimum Nutrition Whey Gold Standard 100% Isolate

  • Ingredient Quality: 89/100
  • Overall Rave Score: 90.6

The Gold Standard 100% Whey Isolate protein supplement by Optimum Nutrition offers several benefits. Each serving contains 25 grams of protein. We like that the formulation boasts both essential amino acids and branched-chain amino acids, even if the strength of these dosages falls slightly below competitors like SHIFTED and Kaged, at 11.4 g of essential amino acids and 5.5 g of branched-chain amino acids.

Optimum Nutrition Gold Standard 100% Isolate,...

The formulation of Optimum Nutrition Gold Standard 100% Whey Isolate includes low levels of total fat (0 g for the Rich Vanilla flavor and 0.5 g for the Chocolate Bliss flavor), less than 5 mg of cholesterol, and just 1 g of carbs and sugar.

If you want the highest-quality whey protein supplement, don’t confuse Optimum Nutrition Gold Standard 100% Whey Isolate with the similarly named Optimum Nutrition Gold Standard 100% Whey Protein, a separate product that contains 24 grams of protein that is “primarily” but not completely composed of whey protein isolate. 

What we love about Optimum Nutrition Gold Standard 100% Whey Isolate is that the product consists entirely of pure, ultra-filtered whey protein isolate rather than a mix of WPI and lower-quality whey protein sources.

The Optimum Nutrition Gold Standard 100% Whey Isolate flavors, Rich Vanilla and Chocolate Bliss, are somewhat basic but generally well-liked. Some users complain about a slightly artificial or chemical taste. Still, most users enjoyed the flavor and described the taste as less intense than some other brands—in a good way.

Optimum Nutrition sells this supplement in multiple sizes, but regular users should buy it in bulk. We love that Optimum Nutrition’s Gold Standard 100% Whey Isolate protein powder supplement is banned substances tested to give athletes—and any fitness enthusiast who is selective about what they put in their body—peace of mind.

Amine Rahal, a Toronto based entrepreneur who is passionate about fitness, diet, and health, highly recommends this option from Optimum Nutrition:

“I recommend Optimum Nutrition Gold Standard whey isolate primarily due to its longevity. It’s been a staple product in the bodybuilding community for decades and is truly seen as the gold standard for quality whey protein isolate. With Optimum Nutrition, you never have to worry about “nitrogen spiking” or artificially elevated protein content—what you see is very much what you get.”

Pros

  • 25 g of protein 
  • Low in carbs, fats, and sugars
  • Includes both essential amino acids and branched-chain amino acids 
  • Banned substance tested
  • A competitive price for a premium WPI product

Cons

  • Slightly lower dosage strengths of amino acids compared to competitors like SHIFTED and Kaged  
  • Fewer flavor options compared to brands like Kaged and Transparent Labs
Optimum Nutrition Gold Standard 100% Isolate,...
  • High Quality Hydrolyzed & Ultra-Filtered Whey Protein Isolate
  • 25 Grams of Protein Per Serving
  • 5.5 Grams of Naturally Occurring BCAAs per Serving

Thorne Whey Protein Isolate

  • Ingredient Quality: 94/100
  • Overall Rave Score: 90.3

Each scoop of Thorne Whey Protein Isolate powder supplement contains 25 g of whey protein isolate, but that amounts to only 21 g of bioavailable protein. You’ll find a balanced amino acid profile, including branched-chain amino acids, in this supplement.

THORNE Whey Protein Isolate - 21 Grams of...

At 100 calories, every scoop includes 4 g of carbohydrates, 1 g of dietary fiber, 1 g of total fat (including 0.5 of saturated fat), 105 mg of sodium, and 10 mg of cholesterol. The 2 g of total sugars, including 1 g of added sugars, put the sugar content a bit higher than other brands on our list. Still, the sugar content is well in the reasonable range, so a scoop of the protein powder won’t consume your sugar allotment for the day.

The formulation is gluten-free, soy-free, and derived from natural flavors and colors. Thorne includes in its Whey Protein Isolate powder 30 mg of a proprietary blend of bromelain and papain enzymes derived from pineapples and papayas, respectively, to help the body better digest protein. It also includes 94 mg of calcium, 1 mg of iron, and 200 mg of potassium.

The Thorne Whey Protein Isolate is available in two flavors: Vanilla and Chocolate. These flavors sound a bit basic compared to other brands on the market, but overall, most users find the taste of the supplement a positive rather than a negative. Still, taste-wise, this protein powder is one of the weaker options on our list. 

Users have complained that the taste is something they “need to get used to,” while other top-performing brands generally had more enthusiastic praise for taste. Some users find the taste a bit too sweet, although generally pleasant.

Subscription discounts are available, offering savings of 10% to 20%.

One of the biggest selling points of Thorne Whey Protein Isolate is its third-party laboratory testing. Users can rest assured that they are safe from contamination because the supplement is NSF Certified for Sport. This factor is particularly beneficial for athletes in organized sports leagues, who could face penalties if they unintentionally consume banned performance-enhancing substances.

Pros

  • Third-party tested and NSF Certified for Sport
  • A balanced amino acid profile that includes essential amino acids and branched-chain amino acids
  • Inclusion of bromelain and papain enzymes to aid digestion and absorption of protein in the body 
  • A competitive price for a premium WPI product

Cons

  • A somewhat lower dose of bioavailable protein (21 g) 
  • Fewer flavor options compared to brands like Kaged and Transparent Labs
  • More sugar than SHIFTED Whey Protein Isolate 
  • Users were more likely to find that they “need to get used to” the taste
THORNE Whey Protein Isolate - 21 Grams of...
  • Absorbable Protein: 21 grams of bioavailable whey protein isolate with flavors and sweeteners...
  • Muscle Support: Helps maintain healthy muscle mass and supports muscle repair after injury or...
  • Tastes Great: Low in calories, sugar, and fat, with flavors and sweeteners derived from natural...

Swolverine Whey Protein Isolate

  • Ingredient Quality: 94/100
  • Overall Rave Score: 90.2

The Swolverine Whey Protein Isolate stands out in the crowded field of protein supplements for being the best whey isolate protein powder for weight loss. Each serving delivers a robust 26 grams of grass-fed, rBGH-free whey protein isolate. 

Swolverine Whey Protein Isolate | 26g Protein,...

This product is particularly aimed at those looking to enhance their athletic performance and strength, providing a rich and creamy texture that makes post-workout shakes something to look forward to.

Swolverine addresses the common issue of under-dosing in the industry. Their formulations are based on dosages proven by research to be effective in enhancing athletic performance.

Swolverine’s Whey Protein Isolate is distinguished by its unwavering commitment to quality, focusing on high-quality, effective ingredients that set the standard in the industry. This dedication extends to its performance-enhancing capabilities, as the product is carefully designed to help athletes boost their performance. 

A key aspect of Swolverine’s ethos is transparency, ensuring their products are free from proprietary blends. This approach allows for clear disclosure of ingredients, instilling confidence in users about what they are consuming and how it contributes to their fitness journey. 

This combination of quality, performance enhancement, and transparency is what makes Swolverine Whey Protein Isolate a standout choice in the crowded field of protein supplements.

Pros

  • 26 g of high-quality whey protein isolate per serving
  • Grass-fed, rBGH-free, Non-GMO
  • Includes added digestive enzymes for enhanced absorption
  • Aids in muscle building and recovery

Cons

  • Limited to Chocolate Milkshake flavor, which may not suit all taste preferences
  • Higher price point compared to some other whey protein isolates in the market
  • Specifically designed for athletes, potentially less appealing for casual health supplement users
  • Does not include additional supplements like vitamins or minerals found in some other protein powders
Swolverine Whey Protein Isolate | 26g Protein,...
  • HIGHLY POTENT WHEY ISOLATE - Contains 26g of grass-fed whey protein isolate per 30g scoop.
  • INCREASED STRENGTH - Your body utilizes essential amino acids, to help build and rebuild lean muscle...
  • IMPROVED RECOVERY - Whey Protein Isolate is fast absorbing, and helps you recover faster after your...

Onnit Whey Isolate Protein Powder

  • Ingredient Quality: 88/100
  • Overall Rave Score: 89.8

The Onnit Whey Isolate Protein Powder is a carefully formulated supplement designed for muscle gains and enhanced workout recovery. This one is particularly known to be one of the best whey protein isolate powders for muscle gain. Each serving packs 20 grams of high-quality Whey Isolate, ensuring a complete amino acid profile for optimal muscle recovery.

ONNIT Grass Fed Whey Isolate Protein - Mexican...

Onnit’s Whey Protein Isolate comes from grass-fed Irish dairy cows, ensuring a premium, non-GMO protein source. The cows are raised on farms with high Animal Welfare Approved standards, grazing an average of 250 days per year. This commitment to quality is evident in the product’s composition and effectiveness.

Onnit takes pride in its holistic approach to wellness. The brand doesn’t just focus on the physical benefits of its Whey Isolate but also considers the overall impact on an athlete’s health and well-being. 

This is evident in their choice to use grass-fed Irish dairy cows, reflecting a deeper commitment to ethical sourcing and environmental consciousness. This holistic approach ensures that users are not just consuming a protein supplement, but are part of a larger ethos that values health, sustainability, and responsible sourcing.

Pros

  • Each serving contains 20 grams of Whey Isolate
  • Complete amino acid profile for muscle recovery
  • Derived from non-GMO, grass-fed Irish dairy cows
  • Supports muscle building and lean body mass

Cons

  • Lower protein content per serving compared to some competitors (20g vs. 25-26g)
  • Limited flavor options may not appeal to all users
  • Higher cost associated with grass-fed, non-GMO sources
  • May not be suitable for individuals with dairy sensitivities
ONNIT Grass Fed Whey Isolate Protein - Mexican...
  • Key Benefits: Supports muscle gain, promotes faster recovery, aids in body recomposition, maintains...
  • Each serving of our protein contains 20 grams of Whey Isolate, offering a complete amino acid...
  • Featuring non-GMO whey protein isolate derived from the milk of Irish dairy cows—animals raised on...

Dymatize ISO100

  • Ingredient Quality: 90/100
  • Overall Rave Score: 91.6

The Dymatize ISO100 is a premium protein powder that excels in both quality and effectiveness. This Vanilla-flavored, hydrolyzed 100% whey isolate protein offers a high-yield protein source designed for rapid absorption and maximum efficacy. This rapid delivery is vital for initiating muscle repair, a critical component in muscle growth and strength enhancement.

Dymatize ISO 100 Whey Protein Powder with 25g of...

This protein powder has 25 grams of protein per serving with only one gram of sugar. It’s scientifically formulated for those aiming for muscle size and strength gains. The hydrolyzed whey protein isolate ensures fast absorption and easy digestion with minimal lactose content.

The versatility of Dymatize ISO100 adds another layer to its appeal. It accommodates diverse dietary preferences and lifestyles and is designed for easy mixing with various liquids, including water, milk, and milk alternatives. This adaptability makes it an ideal choice for individuals seeking a protein supplement that seamlessly integrates into their daily routine, whether they prefer simple shakes or more elaborate smoothies.

Dymatize ISO100 protein powder container positioned by 30lb weights on a wooden table outside

Pros

  • Contains 25 grams of high-quality hydrolyzed whey protein isolate per serving
  • Includes 5.5 grams of BCAAs for muscle support
  • Low in sugar and fat, supporting various diet plans
  • Easily digestible and gluten-free
  • Supports muscle recovery and growth with fast absorption

Cons

  • Limited flavor options with the primary focus on Vanilla
  • Higher price point due to the quality and processing of whey protein isolate
  • Hydrolyzed protein may have a distinct taste that doesn’t appeal to all
  • The intense focus on muscle recovery might not cater to those looking for a more balanced nutritional profile
Dymatize ISO 100 Whey Protein Powder with 25g of...
  • 3 lbs of Dymatize ISO100 Gourmet Vanilla Protein Powder (43 Servings)
  • 25 grams of protein, 5.5 grams of branched-chain amino acids (BCAAs), & 2.7 grams of Leucine per...
  • Less than 1 gram of fat & sugar per serving

Difference Between Whey Protein, Whey Protein Isolate, and Other Protein Powders

A protein supplement can amplify the gains you make through exercise, but not all protein powders are equally beneficial. 

Too many protein powders on the market use a formulation full of cheap, low-quality sources of protein, artificial flavors, and sugar. Some protein powders contain as much as two-thirds to nearly the full maximum recommended amount of sugar in a day. Choosing the right protein powder matters. 

What Is Protein?

Protein is a nutrient the body needs to build and repair muscle. In the body, protein molecules are made up of the amino acids that break foods down into nutrients, grow muscle mass, and rebuild and repair tissues. 

Because proteins are so critical to the functions of the body, the National Library of Medicine’s MedlinePlus reported that they are commonly called “the building blocks of life.” Proteins make up skin, hair, bone, and muscle. 

To grow new muscle (as you accomplish by working out) and sustain and repair damage to existing muscle, you need to consume adequate amounts of the macronutrient protein. Eating protein-rich foods like meat and dairy provides this macronutrient. However, fitness enthusiasts who are exercising intensely and working on building muscle need more protein than a typical diet can provide. 

Protein supplements provide a higher concentration of the macronutrient you need to build muscle than you could consume through food alone. Different protein supplements are derived from different sources. 

Types of Protein Supplements

Most protein supplements are derived from animals in some way. Whey protein is an animal-derived protein supplement, as are casein and egg protein. Some protein supplements on the modern market are plant-based. 

Proteins can also be complete or incomplete, depending on whether they include all nine of the essential amino acids the body needs to consume through dietary ingestion. 

Whey Protein: The Basics

Whey protein, the most popular type of protein supplement, is a complete form of protein derived from dairy. Whey is a by-product of the process of converting cow’s milk into cheese. 

For athletes and gym-goers, there’s a lot to love about whey protein. It’s widely considered the highest-quality and most effective protein supplement source available, thanks to the blend of amino acids it naturally contains—particularly the high content of an essential amino acid called leucine—and its easy absorption by the body. 

What Is Whey Protein Isolate?

Whey protein isolate (WPI) refers to a specific type of refined whey protein. Although whey protein as a whole is generally considered the highest quality of protein, not all forms of whey protein are equally beneficial for exercise enthusiasts. Ultra-refined whey protein isolate is a higher quality supplement than whey protein concentrate. 

Whey Protein Isolate vs. Whey Concentrate

Whey contains a healthy dose of protein, but it can also be full of fats and carbs—exactly what most fitness enthusiasts are looking to reduce when optimizing their diet and increasing their protein intake. 

Whey protein concentrate undergoes a less extensive refinement process than WPI. As such, it contains a lower percentage of protein. At best, whey protein concentrate will be a blend of 80% of actual protein by weight and the remaining 20% consisting of carbohydrates and fats. Certain whey concentrate protein supplements may contain even lower proportions of protein (and higher proportions of carbs and fats). 

That’s why WPI is preferable to whey concentrate. More extensive processing allows whey protein isolate to instead contain at least 90% protein, if not more. The processing steps WPI supplements go through reduce the carbs, fats, and total calories that can upend your otherwise healthy diet. 

4 Key Benefits of Whey Protein Powder

Protein powder supplements serve to boost an individual’s consumption of protein to help them gain, maintain, and rebuild muscle. 

Man holding a protein powder drink while sitting on a workout bench in his garage gym

The benefits of whey protein powder, in general, include the following: 

  • Its effectiveness in providing a high-quality source of protein 
  • The naturally occurring amino acid content, and particularly an essential amino acid called leucine, that supports the building of lean muscle mass 
  • A high degree of digestibility, so the body can easily absorb the protein source

The benefits of whey protein isolate, in particular, are getting significantly more protein and less of the unwanted components—fats, carbs, and extra calories—in each serving. Protein supplements that provide 100% whey protein isolate cost a bit more than lower-quality whey concentrate supplements or supplements that blend the protein sources, but they offer more bang for your buck in terms of enhanced protein consumption. 

Benefit #1: Whey Protein Supplements Build Muscle Effectively

Whey protein’s efficacy in building muscle mass is well-established. In an article published in the journal Nutrition and Metabolism that dates back to 2010, researchers found that dietary protein, and especially whey protein, “stimulate the greatest rise in [muscle protein synthesis]” and “result in greater muscle cross-sectional area when combined with chronic resistance training.” 

Consumption of whey protein can also improve exercise recovery in healthy adults, especially among younger fitness enthusiasts. The extra protein can help restore and rebuild the damage muscles sustain through intense workouts. Jason further explains the importance of recovery:

“The main benefit of having a whey protein is recovery, first and foremost. It doesn’t matter how much or how hard you train. If you are not recovering from your workouts, you aren’t getting anywhere fast. Not recovering fully from workouts can lead to injuries and a total lack of motivation to train.

An optimal whey protein isolate ensures this is never an issue and because it’s so easy to consume your protein via a shake as opposed to food, you will always be recovering and growing from your hard work.”

Benefit #2: Whey Protein Supplements Start Acting Fast

Whey protein is a fast-acting protein, as established by scientific research. Taking whey protein supplements can help you build muscle faster than you could with only the amount of protein you consume through your regular diet. Further, supplements that consist of whey protein begin acting on the body quickly. 

The body can fully absorb an entire serving of whey powder in a matter of two to three hours, researchers reported in a 2018 article published in the Journal of the International Society of Sports Nutrition. That’s about three times faster than the time it would take for the body to digest dietary protein consumed in the form of a cooked egg, according to researchers. 

Once you begin taking whey protein supplements to help you maximize the gains you make in the gym, you’re likely to start seeing results in a matter of weeks. 

Benefit #3: WPI Supplements Contain Optimal Proportions of Protein, Fat, and Carbs

What makes WPI supplements really special is that these refined sources of whey protein give you more of the nutrients you want—protein, of course—and less of the ones you don’t. 

As part of your healthy lifestyle that prioritizes protein consumption, you’re probably striving to reduce your intake of carbs, fats, and sugars. Choosing whey protein isolate supplements over whey concentrate forms of protein allows you to maximize the actual protein you consume. This is especially important for athletes, which Amine goes on to explain:

“A regular diet normally does not supply enough protein for advanced athletes or those with muscle-building goals. Without the help of supplements, consuming 1 gram of protein per pound of body weight is difficult or cost-prohibitive for many individuals.

Protein supplementation with whey protein powder is an excellent way to add to your daily protein intake. Every gram of protein in whey contains a full amino acid profile, making it an ideal source of protein after a workout.”

Benefit #4: WPI Supplements Offer a Better Value

You’ll pay more for 100% whey protein isolate supplements than for whey concentrate supplements, but you’re getting more protein and less of the nutritionally sub-optimal fillers for your money. 

Protein powder supplements are more than a post-workout snack to curb your hunger. They’re an investment in your body and your health. The best investment is one in which you’re getting a return of at least 90% high-quality protein, with minimal fat, carbs, and sugar content. 

Only 100% whey protein isolate supplements, not whey concentrate supplements or whey supplements that blend cheap, lower-quality sources with a small proportion of higher-quality sources, offer this return on your investment. 

How to Use Whey Protein Powder

Whey protein isolate supplements usually come in powder form. Most brands recommend mixing a scoop with plain water. Mixing can be accomplished by adding the powder and water to a shaker cup and giving it a good shake or by hand with a spoon. 

Man holding a scoop of Kaged whey protein powder on a black granite countertop

Protein powder can also be mixed with milk or added to coffee, smoothies, and other foods and beverages. 

The best whey protein isolate powders tend to mix well with water without having a chalky or gritty consistency. They are available in flavors that make the supplement more palatable, ranging from delicious chocolate and vanilla flavors that taste like milkshakes (but healthy) to more complicated flavors. 

When Is the Best Time to Take Whey Protein Powder?

Consuming protein of some kind with every meal may be beneficial for devoted athletes and gym-goers, but there are ideal and less-than-ideal times to take WPI supplements. 

The body is naturally primed to increase muscle synthesis following a workout. Timing your consumption of fast-acting whey protein isolate supplements to align with this period of improved muscle synthesis rates can help you make the most of your body’s natural muscle-building process. 

Ideally, you should take whey protein powder supplements shortly before, during, or after your workout. If you exercise in the morning, you should take protein powder early in the day. After-work gym-goers will take the supplement later in the day.

Fortunately, since whey protein powder supplements don’t typically contain stimulants like caffeine, taking them in the late afternoon or evening shouldn’t keep you up at bedtime. If your workout schedule is variable, adjust when you take your WPI supplement to match. 

Is Whey Protein Powder Safe?

Generally speaking, it’s considered safe for active, healthy adults to consume protein powder in moderation. 

The macronutrient protein is safe to consume. In fact, protein of some kind is necessary for optimal health, even if you’re not a fitness enthusiast. The more active you are, the more need your body has for protein to restore and rebuild your muscles. 

One aspect of the safety of protein powder supplements that is important to consider is toxic contamination. In August 2022, Harvard Health Publishing (by Harvard Medical School) reported that contamination of protein powders is alarmingly common. Researchers have found dangerous levels of heavy metals, pesticides, carcinogens, and other chemicals in protein powders. 

If you’re concerned about contamination, you can feel safer by choosing the best protein supplements on the market. Every protein powder supplement on our list has a reputation for using high-quality ingredients, and some are even third-party tested for quality and contaminants. 

How to Choose a Whey Protein Powder

No one protein supplement is going to be the right fit for every unique body and every set of fitness goals. However, we’re confident that one of the five best whey protein isolate supplements we’ve identified will be likely to help you achieve better results from your workout. 

The first thing to keep in mind when choosing the best whey protein is to look for powders that contain 100% whey protein isolate. These powders will be better quality—containing higher proportions of protein and lower proportions of fats and carbs—than whey concentrate supplements. 

Some supplements market themselves as whey protein isolate supplements, but if you read the fine print, they actually blend whey protein isolate with lower-quality (and cheaper) whey concentrate. 

Consider, too, the amino acid content of your whey protein powder. Protein is made up of amino acids, but the best products on the market often use transparent labeling practices so consumers can see exactly what amino acids they’re ingesting (and how much of each).  

Look for trusted protein brands and for new, cutting-edge brands that get their whey protein isolate from high-quality sources and use formulas backed by science. Although value is important in any supplement you take regularly, don’t reach for the cheapest option available, which is likely to use lower-quality ingredients. With a little research, you can find premium products at competitive, mid-level price points. 

Finally, consider whether you have any specific goals or needs. Some whey protein powders are specially formulated to reduce muscle soreness or to support recovery for serious athletes and hardcore gym-goers who participate in intense workouts. 

Ranking Methodology: How We Ranked the Best Whey Protein Isolate Powder

Narrowing down the entire market of whey protein powders to the top five best WPI supplements isn’t easy. We based our rankings on the following criteria to ensure we found the best of the best. 

A container of Shifted whey protein isolate next to a pair of dumbbells and a bottle blender filled with a protein drink
  • Quality of ingredients: First, we looked for the WPI supplements with the highest quality ingredients. We only considered products that use 100% whey protein isolate, not whey protein blends that just happen to include some whey protein isolate in combination with cheaper whey concentrate. We gave preference to protein supplements that minimized sugars, fats, and carbs while maximizing protein per serving. 
  • Strength: The more actual protein in your protein supplement, the better. We looked for products that not only include plenty of protein per serving but also boast impressive amino acid profiles. 
  • Value: Protein powder supplements, in general, can cost as little as under $1 per serving, but for good protein powder made from high-quality whey protein isolate, you’re going to have to spend a bit more. Every WPI supplement that earned a spot on our top five list has a price point of around $2 per serving or less. Although each product listed has its own strengths and weaknesses, we’ve found each to offer a great value at a competitive price for the quality of their ingredients and the benefits they provide.  
  • Flavor: A bad-tasting whey protein supplement will be a chore to drink, but a good-tasting one will fit seamlessly into your daily routine. The best whey protein isolate supplements are available in crave-worthy flavors that make increasing your protein consumption easy and enjoyable. 
  • Experience: How well does an individual whey protein isolate supplement work? How does it make users feel? How common are side effects? Although every individual’s experience with any given supplement is unique, we evaluated thousands of different users’ experiences with different whey protein isolate powders. 
ProductIngredient QualityTasteValueRave Score
SHIFTED Whey Protein100/100100/10095/10098.3
Transparent Labs Whey90/10095/10095/10093.3
Kaged Whey Protein90/10093/10097/10093.3
Optimum Nutrition Gold Standard89/10090/10093/10090.6
Thorne Whey Protein94/10087/10090/10090.3
Swolverine Whey Protein94/10090/10095/10093.0
Onnit Whey Isolate88/10086/10096/10090.0
Dymatize ISO10090/10087/10096/10091.0

FAQ: How to Make the Most of Your Whey Protein Isolate Supplement

Now that we have highlighted the best whey protein isolate powders for women and men, let’s talk about how to squeeze the most value and effectiveness out of them.

Who Should Use Whey Protein Isolate Powders?

Whey protein isolate is a good option for people who want to build muscle fast and support the recovery of their muscles following intense exercise.

Choosing WPI powder supplements is particularly important for fitness enthusiasts who want to watch their intake of carbs, sugars, and fats. 

Who Should Not Use Whey Protein Isolate Powders?

Some people should not take whey protein supplements, at least not without first consulting their doctor.
People with serious whey or cow’s milk allergies should choose another protein source. Because much of the lactose is filtered out of whey protein isolate, people who are lactose intolerant may be able to tolerate WPI powder supplements, but they should speak to their doctors about the risks and benefits.
If you are pregnant or breastfeeding, you should consult your doctor before using. Minors (under age 18) and those who have known health conditions or are taking medications should speak to their physician.
In general, it’s a good idea to talk to your doctor before starting new supplements.

Can You Take Whey Protein Powders Every Day Safely?

Using moderate doses of protein powder doesn’t mean you need to restrict the consumption of the supplement. You can take whey protein powder supplements daily, but you shouldn’t exceed the recommended dosages. 

Can Whey Protein Powders Help You Lose Weight?

Although whey protein powder supplements help you build muscle, it’s lean muscle mass that you are (ideally) building through exercise and optimal protein consumption. You can use protein powder, in combination with exercise, to help you lose weight.
Because whey protein isolate contains less fat, carbs, and sugars than other forms of whey protein, this type of supplement is a better choice for users who are looking to lose weight.

Which Type of Protein Powder Is the Best Whey Protein Isolate Powder for Muscle Gain?

To maximize your muscle gain, you want to consume larger amounts of protein—and smaller amounts of fat, carbs, and sugar—with each scoop of protein powder.
Whey protein isolate is considered the highest-quality source of protein supplementation. WPI supplements provide the highest concentration of protein per serving, with less of the carbs, fats, and sugar that could make you gain fat instead of muscle.

Can I Take Protein Powder Without a Workout?

Yes, you can take protein powder without working out. It’s a convenient way to meet your daily protein requirements, especially if you’re not getting enough from your diet. Pairing it with regular exercise is recommended for optimal muscle growth and recovery.

Can I Take Whey Protein Before Bed?

Taking whey protein before bed can be beneficial. It aids in muscle recovery and growth during sleep, a crucial time for muscle repair. Just be mindful of your total daily protein intake and dietary needs.

Does Whey Protein Isolate Affect the Kidneys?

In healthy individuals, whey protein isolate typically doesn’t harm the kidneys. However, excessive protein intake can strain the kidneys if you have pre-existing kidney conditions. It’s best to consult a healthcare professional for personalized advice.

Conclusion

Whey protein isolate powders offer a superior blend of high-quality protein, minimal fats, and carbs, catering to those aiming for muscle gain, weight management, and enhanced workout recovery. With options like SHIFTED, Transparent Labs, Kaged, Optimum Nutrition, and Dymatize ISO100, you can find a supplement that aligns perfectly with your fitness goals and dietary preferences.

Jack Kelle

Jack is an entrepreneur, outdoorist, and animal lover with a background in philosophy, psychology, and business. He enjoys music, friends, and family. At RAVE, Jack works as the manager of marketing and content development.