Written by Steve Theunissen | ISSA: CPT & Fitness Nutrition
Fact checked by Robert Iafelice, MS, RD, LDN
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Protein represents the building blocks of the human body. As a result, it is essential for muscle growth, repair, and function. Protein supplements are a popular and convenient way to ensure that your body is getting the protein it needs when it needs it. When it comes down to the best whey protein powder, more likely than not, you are going to be looking for whey isolate. Whey isolate is a form of protein that has become very popular due to its low levels of fat and carbs and its rapid absorption rate.
As you may have noticed, the whey protein market is saturated, and isolates are more numerous than other types. Finding the best whey isolate protein in the midst of such a choice can seem overwhelming. That's where we come in.
For this review, we've gone deep into the whey protein isolate market to separate the best from the rest. The result is the seven best whey isolate proteins on the current market. To make it even easier for you to get the best whey isolate to meet your needs, we've even broken our reviews down by category.
The 7 Top-Rated Whey Isolates
- Overall Best: Kaged Whey Protein Isolate
- Grass-Fed Whey Isolate Protein Powder: Transparent Labs 100% Grass-Fed
- Best Tasting:: Swolverine Whey Protein Isolate
- Budget Pick: BulkSupplements Hydrolyzed Whey Protein Isolate
- For Weight Loss: Clear Naked Whey
- For Muscle Gain: Klean Athlete Klean Isolate
- Best Whey Isolate Protein Powder Blend: Vital Proteins Vital Performance
SFS Pick
Kaged
SFS Grass-Fed Pick
Transparent Labs
SFS Taste Pick
Swolverine
1. Overall Best Whey Isolate Protein Powder: Kaged Whey Protein Isolate
I've tried a lot of protein powders in my 35 years in the fitness industry. Kaged Whey Protein Isolate ranks as one of the best I've ever had and is the number one product on the market right now in terms of taste, mixability, purity, and price.
Let's start with the price. It breaks down to around $1.40 per serving, which is considerably cheaper than most competing whey isolates and is even on par with many whey concentrate powders. Better yet, if you become a Kaged Supplements subscriber, the cost will drop even further - down to around $1.25 per serving.
You get 25 grams of protein with every serving of Kaged Whey isolate. That includes a full 12 grams of essential amino acids. They have also thrown in Protease, which is a digestive enzyme. I have personally found that I'm able to absorb this protein without any gastric upset, which is not the case with other whey isolates, and I'm pretty sure it's due to Protease content.
This protein powder is available in five flavors, I haven't tried all of them, but the two that I have had - chocolate and chocolate peanut butter - were exceptionally good tasting. In fact, I had to check back on the label to make sure that they were actually healthy - which they were! You get just half a gram of fat and 2-4 grams of carbs, depending on the flavor. What's more, all five flavors are completely naturally flavored, so there are no artificial colorings or preservatives in the mix.
Kaged Whey Isolate also mixes really well and won't leave any gritty residue in the bottom of the cup.
Pros
- Well priced
- 25 grams of protein
- 12 grams EAAs
- Great tasting
- Mixes well
Cons
- Doesn't have fruity flavors
MicroPure Whey Protein Isolate is the gold standard for excellence in terms of protein quality and efficacy. MicroPure Whey Protein Isolate also includes 12 grams of highly anabolic...
2. Best Grass-Fed Whey Isolate: Transparent Labs 100% Grass-Fed
Transparent Labs 100% Grass-Fed is the top contender when it comes to getting an all-natural whey isolate. Every ounce of whey in their product comes from American grass-fed beef that is hormone free. You won't find any artificial flavorings, preservatives, or other additives in this product. In fact, it's got just four ingredients:
- Whey isolate protein
- Salt
- Stevia
- Natural flavoring
Each container of Transparent Labs 100% Grass Fed protein provides you with 28 grams of whey isolate. It has a protein-to-weight ratio of 88%, which is one of the highest in the business
. Each 32-gram serving contains 2 grams of carbs and one gram of sugar.
Transparent Labs 100% Grass Fed protein is available in eight tasty flavors, including Cinnamon French Toast and Milk Chocolate. I tasted the Milk Chocolate, and it was delicious. The only problem I had was that it didn't mix as well as I would have liked. While it didn't leave any clumps, it wasn't as smooth and frothy as the likes of Kaged Whey Isolate.
Pros
- Sourced from grass-fed cows
- 28 grams protein
- 88% protein-to-weight ratio
Cons
- Doesn't mix overly well
Grass-Fed Whey Protein Isolate is sourced from grass fed American Cows! It contains one of the industry’s highest protein-by-weight ratios at 88% (28 grams of protein per 32 gram scoop)...
3. Best Tasting Whey Isolate Protein: Swolverine Whey Protein Isolate
Swolverine Whey Protein Isolate delivers 26 grams of whey isolate per serving, with an impressive protein-to-weight ratio of 87%. That protein is sourced from grass-fed cows; Swolverine has also included a couple of key digestive enzymes (Protease and papain) to offset any digestive issues. This is a great addition that can make a big difference, especially if, like me, you experience bloating even when the lactose has been removed from your protein powder.
The best thing about Swolverine Whey Protein isolate has got to be the taste. It comes in an impressive range of flavors, including Vanilla, Chocolate, Honey Cinnamon Peanut Butter, and Mint Chocolate Chip. The one I tried was honey cinnamon peanut butter. I was a bit dubious of that combination, but my fears were put to rest from the first gulp. It was friggin' delicious! The biggest problem you're likely to have with this protein powder is that it tastes so good you'll have to exercise all your self-discipline not to overconsume it!
Pros
- Great tasting
- 26 grams of whey isolate per serving
- Contains two digestive enzymes
Cons
- Low-calorie count means it's not suitable as a mass gainer<
Swolverine's Whey Protein Isolate contains 26 grams of ultra-pure, cold-pressed, rich and creamy, micro-filtered protein per serving. Sourced from the happiest grass-fed cows in America, free of rBGH...
4. Best Budget Whey Isolate: BulkSupplements Hydrolyzed Whey Protein Isolate
BulkSupplements Hydrolyzed Whey Protein Isolate represents the best value for money on the whey isolate market. Bulk Supplements have carved out a niche for top quality, no-frills workout supplements at a great price. This product is a great example of that.
Not only is Bulk Supplements Hydrolyzed Whey Protein Isolate a pure whey isolate product, but it has also been hydrolyzed for vastly improved absorption. Every serving provides you with a whopping 30 grams of protein, along with a high dose of branch-chain amino acids.
There is virtually no taste with this protein powder, which makes it ideal for adding to recipes without affecting the original taste of that food.
I found Bulk Supplements Hydrolyzed Whey Protein Isolate to mix very well, producing a frothy smoothie-like protein drink when mixed with water.
Pros
- Excellent value
- Hydrolyzed for increased absorption
- 30 grams of protein per serving
- Mixes well
Cons
- No flavor options
Looking to give your muscles the support they need to recover and grow? Hydrolyzed whey protein isolate could be just what you need. Made from high-quality whey protein, this supplement is hydrolyzed...
5. Best Whey Isolate Protein For Weight Loss: Clear Naked Whey
Clear Naked Whey is one of the lowest calories whey isolates we've come across. It's got just 70 calories per serving, making this a great choice for people who are trying to lose weight. This is an extremely clean protein powder that provides 100% whey isolate with light, natural flavoring to produce a pleasing taste. You won't find any artificial sweeteners, flavors, or colors in this product.
Each serving provides you with 15 grams of whey isolate. This will be too low for people aiming to add lean muscle mass. For those wanting to maintain their muscle while losing weight, though, it is about right. There is zero sugar and just three grams of carbs in each serving, both of which are also ideal for people on a weight loss quest.
Pros
- Very low calories
- Naturally flavored
- No sugar
- 3 grams of carbs
Cons
- Just 15 grams of protein
Clear Naked Whey starts with 100% whey isolate powder and is then lightly flavored to create a refreshing, high-protein beverage that is perfect for any time of day...
6. Best Whey Isolate Protein For Muscle Gain: Klean Athlete Klean Isolate
Klean Athlete Klean Isolate delivers 20 grams of pure whey isolate in every serving. It includes high levels of all the essential amino acids to promote protein synthesis and improve muscle recovery and muscle protein synthesis post-workout.
The natural vanilla flavor is naturally sweetened with stevia and monk fruit. This produces a pleasant taste that is not too overpowering, making it good as an additional ingredient in baking recipes. This product is NSF Certified for Sport, so you can be confident that it doesn't contain any banned substances.
Every serving of Klean Athlete Klean Isolate contains 90 calories, 3 grams of carbs, and less than one gram of sugar.
Pros
- 20 grams of protein per serving
- NSF Certified for Sport
- Low in carbs and fat
Cons
- Limited flavor options
Containing no artificial sweeteners or flavors, Klean Isolate is a great option to enhance daily protein and amino acid intake. Since protein requirements are typically higher for athletes, Klean Isolate helps athletes...
7. Best Whey Isolate Blend: Vital Proteins Vital Performance
Vital Proteins Vital Performance stands out for its superior mixability. I've personally mixed this powder with nothing but a spoon and a glass. The result was a smooth, clump, and grit-free shake that was very enjoyable. When I put it in a blender, I ended up with a frothy delight that was a joy to drink.
You get 25 grams of protein with every serving of Vital Performance. That includes all nine essential amino acids. There are also 10 grams of collagen, a vital protein for skin, joint, hair, and nail health.
Vital Proteins Vital Performance is 3rd party tested for potency and purity and carries NSF Certification for Sport.
Pros
- Blends very well
- 25 grams protein
- 10 grams of collagen
- 3rd party tested
- NSF Certified for Sport
Cons
- 5 grams of sugar, which is quite high for a whey isolate protein
By combining lactose-free milk protein isolate with collagen peptides, Vital Performance™ Protein Powder delivers 25g of protein designed to complement your fitness routine. This anytime protein powder...
What is Whey Protein Isolate?
Whey protein isolate is a form of protein supplement. It comes from whey, which is a protein that naturally occurs in milk. Whey is a by-product of cheese making. The isolate version of whey protein has had the majority of the lactose and fat removed. This leaves a very high concentration of protein.
Most whey protein isolates have in excess of 90% protein content. This form of whey is also very low in lactose and fat. This makes it a good choice for people who are lactose intolerant or find it hard to digest regular whey protein concentrate.
Whey protein isolate's ability to be quickly absorbed in the body has made it very popular among bodybuilders, athletes, and gym goers. As well as being used as a protein powder supplement, whey isolate protein is also used as an ingredient in many food products.
What's the difference between whey protein isolate, concentrate, and hydrolysate?
While whey proteins come in isolate, concentrate, and hydrolysate forms, they vary in processing, protein concentration, and rate of digestion. Here's an overview of the different methods used:
Whey Protein Concentrate: The most widely used and typically least processed form of whey protein. It often includes some fat and lactose, as well as 70–80% protein on average. It is less processed than other whey protein types; therefore, it might have trace levels of other vitamins and minerals.
Whey Protein Isolate: A more thoroughly processed variety of whey protein that has undergone filtering to largely remove lactose and fat. In comparison to whey protein concentrate, it typically contains more than 90% protein and has less fat and lactose. Whey protein isolate is also easier to digest than whey protein concentrate, making it a good choice for people who have digestive or lactose intolerance problems.
Whey Protein Hydrolysate: Whey protein hydrolysate is a type of whey protein that has undergone partial pre-digestive protein fragmentation. Faster muscle recovery and growth may result from this process' ability to make protein easier to digest and absorb. Due to the additional processing, whey protein hydrolysate is often more expensive than other whey protein forms.
Benefits of taking whey protein powder isolate:
Whey protein isolate is an extremely popular form of protein supplement due to its ability to provide significant benefits. Here's an overview of the research-backed benefits of taking whey protein isolate:
1. More easily digested
Whey protein isolate is simpler to digest than other protein sources since most of the fat and lactose have been removed during processing. A highly concentrated form of protein is created as a result, and the body swiftly breaks it down and absorbs it.
While making whey protein isolate, filtration, ion exchange, and microfiltration procedures are often used. The majority of the fat and lactose is eliminated from the whey protein using these procedures, leaving a highly concentrated protein powder that is easier for the body to digest.
In one study, the rate of protein digestion and absorption was compared between whey isolate and casein protein. Ten healthy men were given a single serving of either whey isolate or casein protein. Researchers then measured the rate of protein absorption and digestion by means of nitrogen balance testing.
The study results showed that whey protein isolate was significantly faster absorbing than casein protein. The whey isolate was absorbed at a rate of 8.5 grams per hour, compared with 6.1 grams per hour for casein. The researchers concluded that whey protein isolate is absorbed faster than casein as a result of its higher solubility and faster gastric emptying rate.¹
2. Low in Fat and Carbs
Because it is low in calories and fat while still providing a significant amount of protein, whey protein isolate is an excellent option for anyone attempting to lose weight. The low fat and carb count also makes whey protein isolate a more heart-healthy choice. It reduces the risk of such conditions as heart disease, diabetes, and high blood pressure.
Whey isolate is a popular choice for people who follow a keto or low-carb diet because of its low carb count.
3. Contains all essential amino acids
The body cannot produce all of the essential amino acids, so they must be obtained through diet. Whey protein isolate includes all of these amino acids. These essential amino acids are tryptophan, valine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, and valine.
Having all of the amino acids makes whey isolate an excellent protein source for muscle growth and repair.
In one study, the nine essential amino acids were added to a low protein intake to see how it would affect men's myofibrillar protein synthesis (MPS) both at rest and after resistance training. The findings demonstrated that, in comparison to a suboptimal protein dose alone, the addition of essential amino acids, particularly leucine, significantly improved MPS both at rest and after exercise. The study came to the conclusion that essential amino acids, particularly leucine, are crucial in triggering MPS and encouraging muscle growth.²
4. Helps with muscle recovery
A high-quality protein that has all the essential amino acids required for muscle repair and growth is whey protein isolate. When we exercise, our muscle fibers experience microtears. Taking whey protein isolate can improve muscle recovery by helping in the healing of these microtears.
Whey protein isolate can supply the amino acids required for muscle regeneration since it is easily absorbed by the body. Whey protein isolate contains amino acids that promote protein synthesis, the process through which the body creates new proteins, including muscle tissue.
Whey protein isolate is also high in branched-chain amino acids, which are extremely important to muscle repair.
The effects of whey protein isolate supplementation on muscle regeneration and recovery during resistance training were examined in a 2013 study that appeared in the Journal of the International Society of Sports Nutrition. Forty-eight young men who participated in resistance training were randomized to receive either whey protein isolate or a placebo.
The study's findings demonstrated that whey protein isolate consumption significantly increased muscle strength and cross-sectional area compared to the placebo group. Also, the group taking whey protein isolate had lower blood levels of indicators for muscle injury, which suggests quicker muscle repair and recovery.³
5. Supports muscle growth
The amino acids in whey protein isolate enter the bloodstream and are transported to our muscles. There, they promote protein synthesis, which is how the body creates new proteins, including muscle tissue. Over time, muscle growth results from this rise in protein synthesis and muscle protein.
The branched-chain amino acids that are present in high concentrations in whey protein isolate can lessen muscle damage and discomfort after exercise and are essential for muscle growth and repair.
Side effects of whey protein isolate:
Whey protein isolate is safe for the vast majority of people. Some people, though, may experience side effects such as gas, bloating, and diarrhea. This is often due to lactose intolerance or sensitivity to other component ingredients in whey isolate.
Because whey protein isolate comes from cow's milk, some people may have an allergic reaction with symptoms including swelling, hives, trouble breathing, and anaphylaxis.
Taking too much whey protein can put too much strain on the kidneys. This could lead to kidney damage. Overconsumption of whey isolate can also result in dehydration. Make sure that you are drinking plenty of water to balance out the increased protein intake.
Some whey supplements have been found to contain heavy metals, including arsenic, lead, and cadmium. Long-term exposure to heavy metals may be harmful to a person's health.
What to look for when buying whey protein isolate:
With so much competition in the protein market, it can be overwhelming trying to find the right product to meet your needs. Here's a guide to help you navigate your way through the protein supplement market to identify the ideal whey isolate product for you.
1. Ingredients
Look for a supplement that contains whey protein isolate from a high-quality source, such as grass-fed cows, and that clearly states the source of the protein on the label.
The amount of protein in each serving should be specified on the label. You should pick a supplement that contains at least 20 to 30 grams of protein per serving.
Whey protein isolate supplements should have a very low carbohydrate and fat content (no more than a few grams of each). Check the label to see how much fat and how many carbohydrates are in each serving.
2. Dosage
Consider your goals when taking a whey isolate supplement. If it is to build muscle, you will want a higher dosage per serving than if you want to maintain your current mass level. A dosage of close to 30 grams per serving is best for muscle growth, while 20-25 grams is suitable for muscle maintenance.
3. Taste
Unless you enjoy the taste of a protein supplement, you probably won't keep taking it. Of course, taste is subjective, but you can get a good idea of how pleasant a product tastes by reading online reviews. Just be careful to check that the great taste is not the result of a lot of extra sugar or artificial flavorings.
4. Testing/transparency
Look for a company that subjects its supplements to third-party testing. This is when independent laboratories conduct third-party testing to certify the product's quality and purity. This guarantees the product is free of impurities and lives up to its label promises.
Check for supplements that have received certification from reliable agencies like NSF, Informed-Choice, or GMP. These certifications guarantee that the product has undergone independent quality and purity testing.
The brand you choose should have transparent labeling. The contents, serving size, and other pertinent information should be stated on the label in legible writing. Beware products that conceal the true amount of ingredients or use proprietary blends.
5. Price
Don't sacrifice quality in order to get a cheaper supplement. Choose a supplement that has undergone purity and potency testing and has premium ingredients, such as whey sourced from grass-fed cows.
When assessing if the price is appropriate, take into account the brand's reputation. Companies with a solid reputation for creating supplements of the highest caliber may charge more than lesser-known ones.
When calculating the price, take into account how much of the supplement there is in each container. A larger container might be more expensive up front, but it might also end up being more economical.
To make sure you're paying a reasonable price, compare the cost of a daily serving with competitor products. To do this, divide the price by the number of servings.
6. Reviews
Reviews from other buyers can give you some important insights into the product. Look out for comments about the taste and mixability of the whey supplement. Look, too, for comments about the effectiveness of the product and whether it causes side effects like bloating, gas, or diarrhea.
Whey Protein Isolate FAQs:
Which is better, whey protein concentrate or whey isolate?
It's difficult to state which type of protein—whey concentrate or whey isolate—is better because all of the best whey protein powders have their own distinct benefits and drawbacks.
Whey protein concentrate is a rapidly digested protein that the body can absorb with ease. It has a low quantity of lactose and fat, which is advantageous for people trying to build muscle and speed up their post-workout recovery. However, for people who are lactose intolerant or trying to reduce their calorie consumption, it might not be the greatest choice.
The amount of protein in each serving of whey protein isolate is higher since it has undergone further processing to eliminate the majority of the lactose and fat. Generally speaking, it costs more than whey protein, but it might be a better choice for those who are lactose intolerant. Whey isolate is also better for people on keto or any other low-carb diet.
Whey isolate is usually more expensive than whey concentrate. So if you don't have lactose intolerance issues and want the best value, you may be better off with a whey protein supplement.
What are the benefits of whey isolate?
The key benefits of whey isolate are that it has a high protein concentration, is very low in fats and carbs, is fast absorbing, and contains all of the essential amino acids.
Is it ok to drink whey isolate every day?
As long as it is used in moderation and according to the suggested dosage, whey protein isolate is usually regarded as safe and can be consumed every day as part of a healthy diet. The quantity of whey protein isolate that is suitable for a particular person depends on their body weight, degree of exercise, and fitness objectives.
It is important to remember that taking protein supplements—including whey protein isolate—in excess might have negative effects like dehydration, renal damage, and gastrointestinal discomfort. It is best to take whey protein isolate in moderation and be sure to follow the recommended dosage.
What is the downside of whey protein?
Some individuals may have digestive problems such as bloating, gas, and diarrhea after taking whey protein. Intolerance to lactose or sensitivity to other whey protein ingredients are common causes of these issues.
As whey protein is made from cow's milk, some individuals may experience allergies. Hives, swelling, breathing problems, and anaphylaxis are all possible signs of an allergic reaction.
The presence of heavy metals like arsenic, cadmium, and lead has been discovered in some whey protein supplements. Prolonged exposure to these metals can be injurious to health.
Whey protein supplements can be pricey, especially if consistently consumed as a part of a fitness or sports nutrition routine. Over-reliance on them may also lead to not eating a balanced whole-food diet.
Should beginners take whey protein concentrate or isolate?
Beginners who want to add muscle mass and effectively recover from their workouts will benefit from taking either whey protein concentrate or whey isolate. Those who are intolerant to lactose or have experienced trouble with bloating or gas when taking protein supplements previously will be better off with a whey isolate supplement. Whey isolate will also digest faster, speeding up protein synthesis. Beginners on a tight budget, though, will be better off with whey protein concentrate.
Summary: Which Whey Protein Isolate is Best?
Whey Isolate Protein powder represents a premium form of protein supplement. Its high protein concentration, low lactose and fat levels, and rapid absorption make it an effective muscle repair and building compound.
The best whey isolate protein powder currently on the market is Kaged Whey Protein Isolate, which provides you with 25 grams of pure protein in every serving, including 12 grams of essential amino acids. It tastes great and has been 3rd party tested for purity and potency.
MicroPure Whey Protein Isolate is the gold standard for excellence in terms of protein quality and efficacy. MicroPure Whey Protein Isolate also includes 12 grams of highly anabolic...
Want more options we didn't cover? Make sure to check out the Best Casein Protein Powders on the market.
References:
- Boirie, Y., Dangin, M., Gachon, P., Vasson, M. P., Maubois, J. L., & Beaufrère, B. (1997). Slow and fast dietary proteins differently modulate postprandial protein accretion. Proceedings of the National Academy of Sciences, 94(26), 14930-14935.
- Churchward-Venne TA, Burd NA, Mitchell CJ, West DW, Philp A, Marcotte GR, Baker SK, Baar K, Phillips SM. "Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men." The Journal of Physiology. 2012 Jan 15;590(2):275-90.
- Hulmi, J. J., Laakso, M., Mero, A. A., Häkkinen, K., Ahtiainen, J. P., & Peltonen, H. (2015). The effects of whey protein isolate on strength, body composition, and muscle hypertrophy during resistance training. Journal of Strength and Conditioning Research, 29(2), 487-495.
Steve Theunissen
Author