Isopure Protein Review: The “Cleanest” Whey? I Tested It

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After over a decade of experience in the supplement industry, I’ve tried hundreds of protein powders (many of which I’ve reviewed here)

Truthfully, most of them start to blend together, and it can be hard for a product to stand out from the pack. 

However, Isopure’s EXCELLENT taste and unique vitamin and mineral blend definitely help set it apart from its competitors. 

Key Takeaways

Honest Review Guarantee from FeastGood: Our testing team purchases each product 100% independently and uses the product for several weeks up to several months before writing a review. Learn more about our review process here.

  • Isopure is an ultra-low-carb whey isolate that provides 25g of protein and only 1g of carbs per serving.
  • Isopure costs between $1.58 and $2.28 per serving, which, for context, is above the average price per serving for protein powders of $1.34. (After researching all the online retailers, this is the most cost-effective place to buy Isopure).  

Overall Rating: 4.3/5

Isopure Protein
Isopure Protein


  • With 25g of protein per scoop, Isopure protein is between 91% and 100% protein per scoop.
  • Isopure contains more than 20 different vitamins and minerals, providing a nutritional boost and some electrolytes above what most traditional protein powders offer.


  • Good Taste & Mixability
  • Added vitamin and mineral blend
  • Isopure offers up to 100% protein per scoop, depending on the flavor.

Best For

  • Someone looking for a convenient way to add both protein and nutrients to their day
  • Someone looking for a good post-workout protein powder
  • Individuals who typically skip breakfast and are looking for a quick option
  • Keto dieters

Medical Disclaimer: The material presented in this article aims to offer informational insights. It should not be perceived as medical guidance. The views and writings are not designed for diagnosing, preventing, or treating health issues. Always consult with your physician prior to starting any new dietary or supplement routine.

About Isopure: Can You Trust The Company?

Isopure advertises itself as a low-carb protein powder. 

This was a relatively novel concept when the product first launched in 1998. 

At that time, significantly fewer brands and options, such as whey isolates and low sugar, were available. 

In the company’s words, they “revolutionized protein drinks with the introduction of Isopure® in 1998”. 

While this may be a bit self-inflated, Isopure does provide a high-quality whey isolate that is gluten-free and low in carbohydrates, sugar, lactose, and fat. 

One thing I really appreciate about Isopure is that they’ve largely remained committed to one product line: protein powders. 

Many brands do their best to occupy as much space on store shelves as possible. 

They do this by branching into every category of workout supplements: vitamins, amino acids, pre-workouts, fat burners, etc. 

It’s uncommon to find a brand that sticks to just one category. 

I believe Isopure has stayed a big name in the supplement industry amidst the hundreds of brands because of their commitment to staying in one lane and delivering the best product in that category.

Isopure offers several types of protein powder, including their low-carb whey isolate (which I am reviewing in this article), a vegan protein powder, collagen, pre-mixed protein drinks, and a juice-like protein powder called Infusions. 

The only products they sell that aren’t protein powder are creatine monohydrate and some apparel. 

Overview of Isopure Protein Powder

Isopure is a whey isolate protein powder with an added vitamin and mineral blend. 

It is available unflavored or has flavored options that use sucralose and natural and artificial flavors. 

The macronutrient breakdown of Isopure protein is: 

  • Protein: 25g  
  • Carbohydrates:  1g
  • Fat:  0.5g
  • Sugar: 0g

Depending on the flavor, Isopure has between 100 and 110 calories per scoop. 

With 25g of protein per scoop, Isopure protein is between 91% and 100% protein per scoop, which is incredibly high for flavored protein powders.

Isopure protein exceeds our criteria for a high-quality protein source because it exceeds 85% protein percent of calories per serving.

Highlights: What I Liked About Isopure Protein

Good Taste & Mixability

I found Isopure mixed easily into a standard shaker cup with no leftover clumps or residue. 

The Dutch Chocolate flavor had an excellent, rich taste even when mixed with simply water. 

I didn’t need a special shaker cup, whisk, or spring ball to mix up my protein powder

During my research, however, I did see that the Vanilla flavor has quite a few negative reviews for being bland or unappealing, but this was NOT my experience with the Dutch Chocolate flavor

Added Vitamin and Mineral Blend

Isopure contains more than 20 different vitamins and minerals, providing a nutritional boost and some electrolytes above what most traditional protein powders offer. 

It is always recommended to get as many of your vitamins and minerals as possible from whole food sources, especially since many supplement brands (Isopure included) use synthetic forms of vitamins and nutrients.

So, I don’t recommend using Isopure instead of eating real, nutritious-rich food like fruits and vegetables, nor do I recommend taking it over a high-quality multivitamin. 

However, the addition of more than 20 different nutrients can still provide a decent health benefit, especially in individuals who may be deficient in these nutrients due to their diet. 

Unbeatable Protein Percentage

Isopure offers up to 100% protein per scoop, depending on the flavor. You cannot find a higher protein percentage than this in the industry. 

That said, I remain slightly leery of products that claim to offer 100% protein per scoop but don’t adhere to third-party testing protocols that could substantiate these claims. 

For example, Transparent Labs has 93% protein percent of calories, but it provides publicly available lab-tested results for the exact bottle that you purchase, so you know the claims are verified.

I have no reason to doubt Isopure’s claims; it would just be nice to offer third-party testing disclosures like other top brands.  

The flavors that offer 100% protein and have 0g of carbohydrates include:

Drawbacks: What I Didn’t Like About Isopure Protein

A Bit More Expensive Than Other Proteins

Isopure costs between $1.58 and $2.28 per serving, depending on which size container you get. This falls above the average price of whey protein powder, which we calculate to be $1.34 per serving. 

For context, our $1.34 per serving calculation includes the full spectrum of protein powders, including various sizes, qualities, and types (isolates, concentrates, etc.). 

The cost of Isopure is almost identical to that of other whey isolates, and in some cases, It is less expensive. 

However, when you factor in the added vitamin and mineral blend and the extremely high protein percentage, the cost of Isopure can be easily justified. 

Not Third-party Tested

Isopure is not third-party tested, making it impossible to verify their label claims. 

Isopure has been around for decades and does have a reputation of quality backing it up. 

Most of the flavors of Isopure advertise as being only 100 calories, meaning the product is 100% protein. 

This does make me slightly suspicious. If all companies could make a product that was 100% protein per scoop with added vitamins and minerals at the cost that Isopure does, then it’s surprising that more brands don’t. 

I am not suggesting Isopure is dishonest, but it is becoming the industry norm for companies to conduct third-party testing and publicly disclose these results to consumers, who are becoming more mindful of how their products are made. 

Isopure Protein Review: My Experience

Isopure Protein user experience

The first thing that stood out was how heavy the tub was when I picked it up. 

Most Isopure protein powder tubs weigh between 1.6 and 2 lbs, but the tub I bought weighed 3 lbs and offered 41 servings. 

The second thing that stood out was how delicious the chocolate flavor smelled when I opened the tub. It felt like I was opening a container of hot chocolate, so I was really excited to dig in. 

I was honestly pleasantly surprised by how good Isopure tasted and how easily it mixed up. 

Products with added vitamin blends tend to have a more gritty texture or poor aftertaste but the Dutch Chocolate flavor was really enjoyable, even when just mixed with water. 

If I am being really judgemental, there’s a very slight grittiness. 

I found it almost unnoticeable, but if you are sensitive to texture, you might pick up on this. It can be easily remedied by mixing the protein powder with milk or a milk alternative or using a blender to mix it. 

Being a low-calorie product that uses only whey isolate, a fast-digesting protein source, I didn’t find this provided great satiety on its own.

When I mixed it with water first thing in the morning, I was hungry within an hour or two. 

I did find it suitable as a breakfast option when added to other things, such as a smoothie or stirred into oatmeal. 

My favorite use for this protein was as an on-the-go snack between activities or as a post-workout option. 

Now that I’ve tried the Dutch Chocolate flavor, I’m really keen to try some of their more unique flavors, like toasted coconut or their juice-like Infusions™ line. 

Overall, I found the value and quality of Isopure to be worth the slightly higher cost per serving. There are very few cases where I wouldn’t recommend Isopure to someone (I’ll elaborate more later).

How Does Isopure Stack Up Against Our Criteria For Whey Protein

At FeastGood, we have eight criteria for ranking whey protein powders.  Here’s how Isopure Protein stacked up:

Nutrition Label Transparency 

Our rating: 4/5

Isopure clearly labels the calories, carbs, proteins, and fats per serving. Furthermore, Isopure provides the full dose and % daily value for vitamins and minerals.

While much of the information on the label is legally mandated, the clean label makes it easy to read and identify all of the information. 

My only criticism of the brand’s transparency is that it doesn’t adhere to some of the same third-party testing standards as other brands. 

On the protein tub, it states that “Isopure® products are tested by our Quality Assurance team laboratories,” which indicates that they test the products themselves instead of hiring an unbiased third party to do this testing. 

Again, I am not suggesting that Isopure would be deliberately deceitful, but it does add a small layer of uncertainty about the quality and purity of its products, especially when many other brands are choosing to disclose their independent testing results. 

Fat Content Transparency 

Our rating: 5/5

Isopure has 0 to 0.5g of fat per serving, which is clearly identified on each flavor’s nutrition label. 

Effective Ingredients 

Our rating: 4/5

Isopure Protein uses whey protein isolate raised without growth hormone. 

They use soy lecithin and xanthan gum for texture and mixability and use a combination of sucralose and natural and artificial flavors for taste. 

The vitamin and mineral blend provides 10 to 250% of the recommended daily value for more than 20 different vitamins and minerals. 

This makes Isopure a good source of electrolytes and can provide additional benefits, such as immune support and skin and nail support. 

My only critique is that for a product that says it focuses on quality protein and thoughtful ingredients, they use artificial coloring in some of its flavors, which is unnecessary and may potentially be linked to negative health outcomes.

Protein Percent of Calories

Our rating: 5/5

Isopure has 25g of protein per scoop and 100-110 calories, depending on the flavor. This means Isopure provides 91-100% protein per scoop, putting it into the excellent category for protein content. 

It is rare to find a product that provides a full 100% protein per scoop. 


Our rating: 4/5

I specifically tested the Dutch Chocolate flavor, which did not disappoint. Even when mixed with water, it had a nice rich, chocolatey taste. 

When I mixed Isopure with the recommended amount of water (6-8oz), it had a great, strong flavor. However, if you try to mix it with higher volumes of water, it gets diluted pretty quickly. 

I enjoyed Dutch Chocolate when mixed into oatmeal or in a smoothie with peanut butter and banana. 


Our rating: 4/5

Isopure mixes up almost entirely with minimal effort. 

There is a very slight grittiness that didn’t affect the experience for me personally, but may be offputting for individuals who are very sensitive to texture. 

I found this slight grittiness wasn’t noticeable when I used something like milk or almond milk instead of water to mix it, or if I used a blender or whisk to mix my protein. 

Texture (Thick or Thin)

Our rating: Thick

Isopure mixes up with a nice, creamy texture and mixes up very thick for a pure whey isolate. 

Typically, whey isolates have a very thin consistency, especially when mixed with water. Isopure had a thick and creamy texture, which was a welcome surprise. 


Our rating: 3.5/5

Isopure only contains whey isolate, a fast-digesting protein. I didn’t find it provided much satiety past about an hour, maybe two. 

That being said, the protein powder’s consistency made it feel more satisfying than other isolate proteins which mix up more thinly.  

Who Is Isopure For? 

Isopure is for: 

  • Someone looking for a convenient way to add both protein and nutrients to their day
  • Someone looking for a good post-workout protein powder
  • Individuals who typically skip breakfast and are looking for a quick option
  • Keto dieters

Who Shouldn’t Take Isopure Whey?

Isopure Whey protein is not for: 

  • Someone looking to avoid any artificial flavors, colors, or additives like gums
  • Someone looking for the most budget-friendly option
  • Individuals who want their protein powder to keep them full and satisfied for several hours

Isopure Customer Reviews

On the Isopure website, the product has a 5/5 star rating, but it is based on only 4 reviews, which is both suspicious and unreliable. 

For a product that claims to have been a pioneer more than 25 years ago, it’s bizarre to me that there are no reviews for the product on their website. 

It’s possible that the website itself or the rating system are new additions (the oldest review on the Isopure website is from only five months ago). 

So instead I checked, where Isopure had more than 12,000 reviews, a much more reliable sample size. 

Overall, Isopure had a 4.6/5 star rating. Here’s a quick breakdown of Isopure Whey user rating out of 5 stars:

  • 5 stars: 78% 
  • 4 stars: 11%
  • 3 stars: 5%
  • 2 stars: 2%
  • 1 star: 4%

There is a lot of positive feedback for Isopure based on taste and mixability. 

Many users praise it as a good option for individuals who are lactose intolerant and claim that they don’t experience any negative side effects from it. (I am lactose intolerant, and I also did not experience any negative side effects.) 

Many individuals proclaimed that “this is my go to product”, one that they have used and loved for years.

Quite a few keto and low-carb dieters also appreciated the extremely low amount of carbohydrates (0-1g) in Isopure. 

When I filtered the reviews to see what the individuals who gave 1 or 2 stars had to say, there were a few common themes. 

The first recurring complaint was about the vanilla flavor. It has been described as tasteless, terrible, or chemically tasting.

The other big complaint has been products on not being Authentic Isopure products. You can tell if your product is authentic because it will have a logo and QR code that you can printed on the label.

Here is the code on my product, which takes you to a website where you can select your country and see the various ways you can recognize if your product is an authentic Isopure product or not. 

Isopure Protein QR code

(I’ll save you the extra step, you can choose your country and get taken directly to the appropriate authentication page: United States, Canada, Mexico, India)

One other negative review that stood out to me had to do with the tub design. 

One user claimed that the opening of the tub was so small he couldn’t comfortably get his hand in or out. 

As it turns out, the diameter of the Isopure protein container opening is anywhere from a quarter of an inch to a full inch smaller than any of my other protein tubs.

I am not sure this will necessarily impact whether or not you purchase this product. 

Isopure Protein tub openings

Isopure Promotions & Discounts

Isopure offers 15% off your first order when you sign up for their newsletter. 

They also have seasonal offers on their website. 

For instance, at the time this article is being written, they are offering a free shaker cup with every purchase of their 4.5lb unflavored protein powder. 

Where To Buy Isopure? 

Isopure is available on Amazon.. 

I have also found Isopure in limited flavors or sizes available at,, The Vitamine Shoppe, and Target.

Isopure Alternatives

Transparent Labs Grass-Fed Whey

For individuals who like the appeal of a high-quality whey isolate but want to avoid artificial flavors, sweeteners, and colors, I recommend Transparent Labs Grass-Fed Whey Isolate

Transparent Labs Whey offers 28g of protein per scoop and is still low calorie (130-140) offering up to 93% protein per scoop. 

It is a low carb formula, similar to Isopure with between 0g and 3g of carbohydrates per scoop, depending on the flavor. 

Isopure is third-party tested, and the results are publicly disclosed, which gives you added reassurance that their products are as high quality as they claim and don’t contain any ingredients not listed on the label. 

Transparent Labs Whey is available for between $1.73 and $2.00 per serving, matching the approximate cost of Isopure. 

The only place Isopure edges out Transparent Labs is that Isopure contains the added vitamin and mineral blend which Transparent Labs does not have. 

Available in 15 different flavor varieties, including an unflavored option which has 0g of carbs, 

Transparent Labs is the ideal alternative for the customer who prioritizes all natural ingredients, no additives, and transparent third party testing. 

Frequently Asked Questions

Where Is Isopure Made? 

Isopure is manufactured in the USA in Illinois. It uses ingredients of both international and domestic origin. 

What Is Isopure’s Shipping Policy? 

Standard shipping is $5.99 or free with a $75 purchase. Standard shipping times are 3-8 business days within the US. There is an expedited 1 business day shipping option available for $16.99. The Isopure website does not allow international shipping.

What Is Isopure’s Return Policy? 

Isopure may accept returns only on items purchased directly from the Isopure website. The merchandise must be returned within 30 days of purchase with the purchase order number provided. To initiate a return, contact customer service to determine eligibility before sending your product back.

Is Isopure Third Party Tested? 

Isopure is not third party tested. On the physical label, it says that “Isopure IRO products are tested by our Quality Assurance team laboratories” which indicates that the testing is done by the company themselves and not an independent third party. 

Is Isopure Good For Weight Loss? 

Isopure is a low carb and low calorie way to get added protein into your day which can support fat loss when paired with an appropriate diet and exercise. There are no specific ingredients in Isopure to cause direct weight loss. 

Is Isopure Keto Friendly? 

Isopure is a low carb formula that is suitable for keto dieters. 

Is Isopure Gluten Free? 

Isopure protein powder is gluten free. 

What Are The Best Ways To Mix Isopure? 

Isopure mixes easily into water, milk, or any milk substitute. It can also be enjoyed blended into a smoothie or stirred into yogurt, coffee, or oatmeal. The Isopure website offers a variety of protein recipes as well

What Flavors Are Available For Isopure? 

Isopure is available unflavored or in 8 different flavor varieties: Banana Cream, Chocolate Peanut Butter, Cookies & Cream, Creamy Vanilla, Dutch Chocolate, Strawberries and Cream, Toasted Coconut, and Vanilla Salted Caramel. 

Does Isopure Make You Gain Weight? 

Isopure is very low calorie and is unlikely to contribute to any weight gain. You could take it after workouts and as part of a high protein diet to support muscle recovery and muscle building. 

Can you use Isopure as A Meal Replacement? 

Isopure on its own is not a good meal replacement. Though Isopure does have a good vitamin and mineral support blend, it is made up of fast-digesting protein and is very low calorie, making it unsuitable as a meal replacement. Consider adding it to a smoothie or as part of a meal. 

When Is The Best Time To Take Isopure?

Isopure can be taken any time of day. Consider trying it as part of a breakfast, post-workout, as a snack, or any time of day where extra protein might be desired.  

How To Contact Isopure 

You can reach out to customer support Monday through Friday from 8:30am – 5:00pm CST. You can do this by phone at 1-877-309-3329 or by email at 

You can also submit any queries via their contact page, found here.

For a more casual connection, find Isopure active on Facebook, Instagram, X(Twitter) (not updated since 2022), Youtube, and Pinterest.


Miller, M.D., Steinmaus, C., Golub, M.S. et al. Potential impacts of synthetic food dyes on activity and attention in children: a review of the human and animal evidence. Environ Health 21, 45 (2022).

About The Author

Jennifer Vibert

Jennifer Vibert is a Certified Strength and Conditioning Specialist, Nutrition Coach, and supplement store manager. She has a Bachelor of Kinesiology with a major in Fitness and Lifestyle and a minor in Psychology from the University of Regina. She is a Certified Nutrition Coach through Precision Nutrition, with a passion for helping clients learn the fundamentals of nutrition and supplementation in order to build healthy, sustainable habits.

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