EXPERT TESTED: Transparent Labs vs Optimum Nutrition Protein

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I tested both Transparent Labs and Optimum Nutrition protein for 1-month each and have already published a library of content detailing my experiences on  

You can find my in-depth reviews of each product here and my YouTube videos here and here.

However, after publishing these reviews, I received many requests for my opinion on their differences and which was better.  

As such, the goal of this article is to compare Transparent Labs protein to Optimum Nutrition protein head-to-head across seven key categories: 

After tallying the scores from each category (more details below), Transparent Labs came out as the clear winner.  

With that said, Optimum Nutrition is still a good pick, but for different reasons.  

Deciding which is best depends on your preferences and the key benefits you want from your protein powder. 

Note: For clarity, I will refer to Transparent Labs 100% Grass Fed Whey Isolate as “TL Whey Isolate” and Optimum Nutrition Gold Standard 100% Whey as “ON Gold Standard Whey”. 

Key Takeaways

Prefer to watch? Check out our video of Transparent Labs vs Optimum Nutrition.
  • The main difference between Transparent Labs Grass Fed Whey and Optimum Nutrition Gold Standard is that Transparent Labs uses exclusively whey isolate (fast digesting) and no artificial ingredients. Gold Standard, conversely, uses a blend of whey proteins (isolate, concentrate, and peptides) and has artificial additives.
  • Transparent Labs is best for those looking for a high-quality, stevia-sweetened protein powder with a very high protein percentage per scoop (93%). When compared to Optimum Nutrition on taste, Transparent Labs won.   
  • While Optimum Nutrition comes at a lower protein percentage per scoop (80%), it’s more affordable than Transparent Labs, which is best if you’re on a budget.  You also have to be okay with artificial flavors and colors. 

Note: If you want to try TL Whey Isolate or ON Gold Standard Whey, I have extensively researched the most affordable places to buy them. If I find better prices, I will update the links below. 

Transparent Lab Whey Protein Isolate

Transparent Labs Whey Protein

The Transparent Labs Grass-Fed Whey Isolate is the #1 protein that recommends.

Gold Standard Whey Protein

Gold Standard Whey Protein

ON Gold Standard Whey uses a blend of whey isolate, whey concentrate, and whey peptides. It’s available in a wide variety of flavors making it likely you’ll find one you like.

What Is Transparent Labs Whey Isolate?

Prefer to watch? Our video producer, Matteo, summarizes the key benefits and drawbacks of Transparent Labs Whey Protein

TL Whey Isolate uses exclusively grass-fed whey isolate, which is important for several reasons. 

First, isolate proteins have gone through some of the most thorough filtration, resulting in a protein powder with virtually all carbohydrates and fats removed. 

transparent labs whey isolate

TL Whey Isolate has 28g of protein per scoop and 120 calories, making it 93% protein per scoop. 

That is, 93% of the product’s calories come directly from protein. This puts it in the “excellent” category for protein content. ON Gold Standard Whey, for instance, only has 80% protein per scoop. 

To put this into context, though, some protein powders we’ve tested on contain as little as 60% protein per scoop. 

Transparent Labs uses exclusively grass-fed whey protein, so the cows are fed a grass-only diet and generally have a higher quality of life. While this doesn’t impact the quality or nutrient profile of the whey protein, it is notable if a high quality of life for the cows is important to you. 

One thing that stands out about TL Whey Isolate is that it contains no unnecessary ingredients. The only ingredients in TL Whey Isolate besides the protein are salt, stevia, and natural flavors. 

TL Whey Isolate is third-party tested, and the results are publicly available on the website. This means you can view the exact results from the bottle that arrives at your house.  The benefit is that you know 100% what’s inside your protein (hence the name “Transparent Labs”).   

TL Whey Isolate is also Informed Choice Certified and Informed Protein Certified, which provides an additional reassurance that this high-quality product is safe for elite athletes who undergo drug testing. 

informed choice certified and informed protein certified

At $2.00 per serving, TL Whey Isolate is more expensive. When we evaluated more than 30 different protein brands on the market, we found the average cost per serving of whey protein to be around $1.34. 

That being said, TL Whey Isolate tastes great, mixes well, and has some of the industry’s highest quality standards, which justifies the cost per serving. 

Want more info?  Read my in-depth Transparent Labs Grass Fed Whey Review here.  


  • Grass-Fed Whey: Grass-fed cows are typically pasture-raised and have a higher quality of life compared to other farming practices, which may be a moral preference for you. 
  • High percentage of protein per scoop: Because Transparent Labs uses only whey isolate, it has very little carbs or fats and provides 93% protein per scoop. 
  • No artificial flavors, colors, or preservatives: Transparent Labs prides itself on using all-natural, high-quality ingredients in its formula. The protein does not contain artificial flavors, colors, or preservatives. 
  • Great taste with a wide variety of flavors: TL Whey Isolate is available in 15 different desert-like flavor varieties. In 2023, I personally tested every available flavor, and there wasn’t a single one that I didn’t think I could integrate into my routine.
  • Third-Party Tested and Informed Choice Certified: This publicly disclosed third-party testing provides reassurance that what is found in the tub matches what is printed on the label. The Informed Choice certification makes it safe for use by drug-tested athletes. 


  • Higher Cost Per Serving:  I consider the cost justified if you prioritize a high protein percentage and the highest quality ingredients. 
  • May not provide much satiety: Whey Isolate is a fast-digesting protein. Because it is the only source found in TL Whey Isolate, you might feel hungry within an hour or two after taking it. 
transparent labs whey isolate

Who Should Take It? 

Transparent Labs Grass-Fed Whey Isolate is a good option for: 

  • Individuals who prioritize high-quality ingredients
  • Anyone looking to avoid artificial flavors or sweeteners
  • Athletes who undergo drug testing 
  • Those with a more generous supplement budget
  • Individuals who are concerned about the health and quality of life of the cows supplying the dairy
  • Anyone with a lactose sensitivity, with very low sugar, this product is very low in lactose and may be less reactive

What Is Optimum Nutrition Gold Standard Whey?

Prefer to watch? Our video producer, Matteo Cantagallo, highlights the pros & cons.

ON Gold Standard Whey uses a blend of whey isolate, concentrate, and peptides. 

Whey isolate is a fast-digesting protein, and whey concentrate is a slightly slower-digesting protein that goes through slightly less filtration. 

As a result, it still has some of the remaining carbohydrates and fats that occur naturally in milk. This is the main source of the small carbs and fats found in the ON Gold Standard Whey Formula. 

optimum nutrition gold standard whey

The third protein source in the smallest concentration, whey peptides, are amino acids. These are the building blocks of protein isolated from longer protein chains. They may have immune-boosting properties and improve the rate of muscle growth

With 120 calories and 24g of protein per scoop, ON Gold Standard Whey is 80% protein per scoop, which is still good but not quite as good as TL Whey Isolate. 

Our general guideline is that a “good” product has 75-85% protein per scoop and excellent products have higher than 85% protein per scoop. 

This protein blend allows ON Gold Standard Whey to be cheaper. Depending on the size of the container, the cost per serving ranges from $1.06 to $1.54. This puts it well below the cost of Transparent Labs and the average industry cost. 

ON Gold Standard Whey uses artificial sweeteners like sucralose and acesulfame potassium, as well as natural and artificial flavors. Some flavors contain additional ingredients like cookie crumb pieces or artificial food dyes to enhance the visual experience of drinking the protein powder. 

Several other ingredients are added to the ON Gold Standard Whey formula, including gum blends like xanthan gum and guar gum, which can act as thickeners and provide a different mouth feel, and lecithins, which provide better mixability. 

ON Gold Standard Whey is Informed Choice certified, meaning it undergoes third-party testing and is safe for use by drug-tested athletes. 

Looking for more info?  Read my in-depth ON Gold Standard Whey Review here.  

ON gold standard whey


  • Wide variety of flavors: Optimum Nutrition’s website lists 20 flavor varieties. This big selection makes it very likely that you will find a flavor that suits your preferences. 
  • Informed Choice Certified: ON Gold Standard Whey is Informed Choice Certified, meaning it undergoes additional third-party testing as a quality assurance and is safe for use by drug-tested athletes. 
  • Low cost per serving: Depending on the size of the container, ON Gold Standard Whey is well below the industry average of $1.34. Other protein powders at this price point, like Six Star Whey Protein are typically very low quality and only contain 60-65% protein per scoop. 
  • Versatility: The ON Gold Standard Whey blend makes it suitable as both a post-workout recovery protein (due to the whey isolate and whey peptides) and any time of day or between meal protein (because whey concentrate digests more slowly and will provide more satiety). 


  • Mixability:  Despite the additives like lecithins, which are supposed to improve mixability, I found there were still small clumps left over and some undissolved residue. This wasn’t enough to completely turn me off the product, but it was noticeable. 
  • Use of artificial flavors: This comes down to personal preference, but ON Gold Standard Whey uses artificial flavors and sweeteners. Some individuals (including me) are choosing to reduce or eliminate these ingredients from their diet. 
  • Unnecessary Additives: Optimum Nutrition adds soy and sunflower lecithin, gum blends, and food dyes to their protein powders. None of these ingredients improve the quality of the product but provide non-nutritive “benefits” such as better texture and mouthfeel or a brightly colored protein shake. 
gold standard whey

Who Should Take It? 

Optimum Nutrition Gold Standard Whey is a good option for: 

  • Someone looking for a budget-friendly protein
  • Athletes who undergo drug testing 
  • Someone looking for an “any time of day” protein
  • Someone who gets bored with flavors easily

Main Differences: Transparent Labs Whey Isolate vs O.N. Gold Standard 


🏆 The Winner: Transparent Labs

Other than the fact that both are third-party tested protein powders, there are virtually no other similarities between the two. 

TL Whey Isolate and ON Gold Standard Whey differ in the types of protein they use, the percentage of protein per scoop, how the products are flavored, and whether they contain non-nutritive additives like gums and artificial colors. 

Overall, TL Whey Isolate has a more natural ingredient list.  

transparent labs vs optimum nutrition protein ingredients

*For the nutrition facts, I have compared the two French vanilla flavors head to head. There are slight variances in calorie and carbohydrate content depending on the flavors

Quality Assurances

🏆 The Winner: Transparent Labs

Transparent Labs focuses on using the highest quality ingredients in its formula and cuts out all artificial additives. Optimum Nutrition does not have this same standard. 

Both products are Informed Choice certified, safe for use by drug-tested athletes, and endorsed by some of the best athletes in the world. 

Transparent Labs stands out for its commitment to publicly disclosing the results of its third-party testing and keeping artificial flavors, colors, and preservatives out of its protein powder. 

ON Gold Standard Whey has lower standards, and the use of artificial ingredients and their blend of protein sources helps keep the overall cost lower. 

Protein Percent of Calories

🏆 The Winner: Transparent Labs

TL Whey Isolate has the advantage with 93% of its calories coming from protein. ON Gold Standard Whey is 80% protein per scoop, with the additional 20% coming from carbs and fats. 

Both protein powders contain 120 calories per scoop. TL Whey Isolate, however, has 28g of protein compared to ON Gold Standard Whey which has 24g. 

This protein content difference catapults TL Whey Isolate into the “excellent” category of protein percentage and keeps ON Gold Standard Whey in the “good but not great” category. 

Note that the additional carbs and fats in ON Gold Standard Whey are not added to the protein but are naturally occurring from the whey concentrate. 


🏆 The Winner: Transparent Labs

Both products offer a wide range of flavors. Optimum Nutrition has 20 flavors compared to the 15 offered by Transparent Labs. 

Taste is subjective, and in my experience thoroughly testing both products, I found that TL Whey Isolate had a stronger overall taste, and some of the flavors of ON Gold Standard Whey seemed a bit bland. 

This is why I gave the win to TL Whey Isolate.  

However, some individuals find that products that are sweetened exclusively with stevia have a bitter or unpleasant aftertaste and, therefore may prefer the taste of ON Gold Standard Whey. 

Note: If you want to learn more about the taste of TL Whey Isolate, I tried and tested every single flavor, which you can read about here or watch my YouTube video: 


🏆 The Winner: Transparent Labs

There were no significant differences in mixability between the two brands, aside from the fact that there was some very slight clumping or undissolved residue with ON Gold Standard Whey.  While minor, I didn’t experience this with TL Whey Isolate.  

Texture (Thick or Thin)

🏆 The Winner: Tie

Both proteins are mixed up with similar thin but smooth textures. 

I found TL Whey Isolate mixed up with a creamier texture when compared to other pure isolate proteins, and I found that ON Gold Standard Whey mixed up quite thin, like a pure isolate, despite having whey concentrate in its formula. 

They were both outliers when compared to other products in their respective protein categories, but in the end, both are very similar. 


🏆 The Winner: Optimum Nutrition Gold Standard

Optimum Nutrition Gold Standard will provide slightly more satiety (feelings of fullness) when compared to TL Whey Isolate because of the addition of whey concentrate. 

Ultimately, both protein powders are low in calories, with about 120 calories per serving. 

Any product that has these few calories will not be great for providing prolonged fullness but will improve satiety if it is used as part of a snack or meal that contains healthy fats and fiber. 


🏆 The Winner: Optimum Nutrition Gold Standard

This might be the most significant difference between TL Whey Isolate and Gold Standard Whey. 

TL Whey Isolate is among the most expensive, costing $2.00 per serving, whereas ON Gold Standard Whey is among the lowest at as low as $1.06 per serving.

For those individuals who prioritize high-quality products, quality of life for the animals, and are looking to avoid artificial ingredients then the high cost per serving of TL Whey Isolate is justifiable. 

Those on a tighter budget and less concerned with those details can choose ON Gold Standard Whey as a high-quality protein powder that still offers 24g of protein per serving. 

Where To Buy

Transparent Lab Whey Protein Isolate

Transparent Labs Whey Protein

The Transparent Labs Grass-Fed Whey Isolate is the #1 protein that recommends.

Gold Standard Whey Protein

Gold Standard Whey Protein

ON Gold Standard Whey uses a blend of whey isolate, whey concentrate, and whey peptides. It’s available in a wide variety of flavors making it likely you’ll find one you like.

What Other Experts Are Saying

  • Taylor Fritz, Top US Pro Tennis Player, is an Optimum Nutrition-sponsored athlete who uses Gold Standard Whey as a part of his diet and recovery regime. He emphasizes that it’s his actions, both on and off the court, that affect his overall performance and that it’s important that he fuels himself properly. Taylor trusts the high quality of Optimum Nutrition protein to fuel him after training sessions, matches, and while on the road. You can find his favorite shake recipe here.


Gilmartin, S.; O’Brien, N.; Giblin, L. Whey for Sarcopenia; Can Whey Peptides, Hydrolysates or Proteins Play a Beneficial Role? Foods 2020, 9, 750.

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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