Optimum Nutrition protein review 2024: our expert insights
Protein powders
are a staple in many fitness routines, helping people meet their protein needs, support muscle recovery, and enhance performance. Optimum Nutrition is one of the most recognized brands in the market, offering a variety of protein powders to suit different dietary preferences and fitness goals. From whey and casein to
plant-based proteins
, their product range is designed to cater to everyone, from casual gym-goers to elite athletes.
Our team of nutrition and fitness experts reviewed seven of Optimum Nutrition’s protein powders and analyzed each product for its protein content, ingredient quality, taste, and overall value. We compared these products to similar options on the market to provide you with an informed recommendation for your dietary needs. Read on to find out which Optimum Nutrition protein powder may be best for your lifestyle and fitness goals.
Medical disclaimer: This article is intended for educational and informational purposes only. It is not intended as a substitute for medical advice. For health advice, contact a licensed healthcare provider.
Our picks for the best Optimum Nutrition protein supplements
Compare Optimum Nutrition protein supplements
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ON Gold Standard 100% Whey |
ON Gold Standard RTD Protein Shake |
ON Platinum Rebuild |
ON Platinum Hydrowhey |
ON Gold Standard 100% Isolate |
ON Gold Standard 100%Casein |
ON Gold Standard 100% Plant |
|
|
Rating |
|||||||
|
Price per serving |
$1.06-$1.67 | $2 | $3 | $2.50- $2.75 | $1.66- $1.96 | $1.74-$2.16 | $1.85- $2 |
|
Protein type |
Whey protein isolate, whey protein concentrate, hydrolyzed whey protein | Milk protein isolate, milk protein concentrate, whey protein concentrate | Micellar casein, whey protein concentrate, whey protein isolate, hydrolyzed whey protein isolate | Hydrolyzed whey protein isolate, BCAAs | Hydrolyzed whey protein isolate, whey protein isolate | Micellar casein | Pea protein, fava bean protein isolate, brown rice protein concentrate |
|
Protein per serving |
24 grams | 24 grams | 24 grams | 30 grams | 25 grams | 24 grams | 24 grams |
|
Flavor options |
20 | 3 | 2 | 3 | 2 | 4 | 2 |
Gold Standard 100% Whey offers 24 grams of protein and 5.5 grams of BCAAs per serving and is available in various flavors.
Key product features
Solubility
Excellent
Flavors
20 options
Third-party tested
Yes
Gluten-free
Yes
BCAAs
5.5 grams
What you should know
Optimum Nutrition Gold Standard 100% Whey is a versatile, high-quality protein supplement designed for muscle recovery and growth. It offers 24 grams of protein and 5.5 grams of BCAAs (branched-chain amino acids) per serving.
-
Our expert product testers gave Gold Standard 100% whey perfect scores for solubility. Delicious strawberry, mocha cappuccino, and double rich chocolate were the most well-liked flavors.
-
Priced between $1.06 and $1.67 per serving, it’s a solid value compared to other whey proteins in the market.
-
Ideal for athletes and fitness enthusiasts looking for a reliable protein supplementation with a variety of flavor options.
Pros
Balanced blend of whey isolate, concentrate, and hydrolyzed whey
Banned substance tested through Informed Choice
Cons
Contains artificial sweeteners
Contains artificial flavors
Protein content is lower than some competitors
Gold Standard 100% Whey overview
Optimum Nutrition Gold Standard 100% Whey is a popular choice for anyone looking to
boost their protein intake,
whether for muscle building, recovery, or general nutrition. It’s made with a blend of whey protein isolate, concentrate, and hydrolyzed whey protein, providing a solid 24 grams of protein per serving. The mix of protein types ensures a balance between fast absorption from the hydrolyzed whey and slower digestion from the concentrate, making it useful for both post-workout recovery and daily protein supplementation. (
1
,
2
)
Each serving delivers 5.5 grams of BCAAs, which are key for supporting muscle repair and recovery. BCAAs, especially leucine, are known to play a crucial role in muscle protein synthesis, making this powder a good option for those looking to support muscle growth or recovery from exercise. (
3
,
4
) At between 120 and 130 calories and 1 to 2 grams of sugar per serving, it’s a low-calorie option that fits well into most nutrition plans without adding excessive sugars or fats.
Optimum Nutrition’s Gold Standard Whey stands out for offering 20 flavor options, which is a rarity among protein powders. This variety allows users to switch things up and avoid flavor fatigue, which can be an issue for those using protein powder regularly.
However, it’s important to note that the product is sweetened with sucralose and acesulfame potassium. While this helps keep the sugar content low, some consumers may prefer more natural sweeteners. The inclusion of both natural and artificial flavors may also be a downside for those prioritizing a completely natural product.
“I ordered delicious strawberry, and it’s amazing! Even my kids liked it. However, mocha cappuccino is my new fave. It’s chocolatey and a bit coffee-flavored. It’s great mixed with iced coffee. Solubility-wise, I had no issues mixing it with milk in a shaker cup. The consistency was a bit too thin, though.”
Team Product Tester
One of the standout features is that this protein powder is banned-substance tested through Informed Choice, making it a safer option for athletes or those concerned about contamination with prohibited substances. The product is also free from artificial growth hormones, adding another layer of reassurance for health-conscious consumers.
In terms of cost, Optimum Nutrition Gold Standard 100% Whey is priced between $1.06 and $1.67 per serving, depending on the flavor and size you choose. This is in line with, or slightly more affordable than, other whey protein powders on the market.
What customers are saying
On Amazon, Optimum Nutrition Gold Standard 100% Whey is a best-seller with over 213,000 ratings. Customers regularly leave positive reviews about the taste, solubility, protein content, and value.
“The taste is fantastic, making it easy to incorporate into my daily routine. Whether I mix it with water or milk or blend it into a smoothie, it always delivers a smooth and creamy texture without any unpleasant aftertaste.”
Ternall C. Amazon
“This is, in my opinion, one of the best protein powder brands due to its consistent quality overall,” writes an Amazon customer with the username Canadianlilyberry. “Great taste, fun flavors, ingredients (not perfect but works for us) and price. We’ve tried all kinds of protein powders and we just keep going back to Optimum Nutrition.”
Many reviewers pointed out that some flavors are much better than others. It seems like the double rich chocolate has the most negative reviews.
“This stuff is nasty! It barely has any flavor. It tastes like I would imagine a chocolate-flavored piece of chalk would taste like it would if you licked it off the blackboard,” writes Chevis C.
Who Gold Standard 100% Whey is recommended for:
- Athletes and fitness enthusiasts looking for a versatile, fast-absorbing protein for recovery and muscle growth
- Those who appreciate a wide variety of flavor options in their protein supplement
- Competitive athletes seeking a protein powder tested for banned substances
- Individuals looking for a balanced protein supplement with a mix of whey isolate, concentrate, and hydrolyzed whey
Who Gold Standard 100% Whey is not recommended for:
- People who prefer natural sweeteners and flavors, as this product contains sucralose and artificial ingredients
- Individuals looking for higher protein content per serving, such as 30 grams or more
- Individuals who are lactose intolerant
- People following vegan diets
Specs
|
Protein type |
Whey protein isolate, whey protein concentrate, hydrolyzed whey protein |
|
Calories |
120-130 |
|
Protein per serving |
24 grams |
|
Flavors |
Banana cream, chocolate coconut, chocolate hazelnut, chocolate malt, chocolate mint, chocolate peanut butter, cinnamon roll, coffee, cookies & cream, delicious strawberry, double rich chocolate, extreme milk chocolate, French vanilla creme, fruity cereal, mocha cappuccino, rocky road, strawberries & cream, strawberry banana, vanilla ice cream, white chocolate |
|
Third-party testing |
Informed Choice |
|
Price per serving |
$1.06-$1.67 |
This RTD Protein Shake offers 24 grams of protein and 24 vitamins and minerals.
Key product features
Solubility
Excellent
Flavors
3 options
Gluten-free
Yes
Low sugar
1 gram
Low Fat
2.5-3 grams
Form
Ready-to-drink
What you should know
Optimum Nutrition Gold Standard RTD Protein Shake is a convenient, ready-to-drink option with added vitamins and minerals. Here’s what you need to know:
-
It provides 20% of the daily value of 20 different vitamins and minerals, including vitamins A, C, D, E, and zinc. Plus, it’s gluten-free and low in sugar, making it suitable for various diets.
-
At $2 per serving, it’s a bit more expensive than the average powdered protein but reasonable for the convenience of a ready-to-drink shake.
-
Ideal for those seeking quick, portable protein with added nutrients to support immune function and bone health.
Pros
Convenient option for on-the-go nutrition
Contains 24 grams of protein and 24 vitamins and minerals
Added vitamin D, C, and zinc
Cons
Sweetened with sucralose and acesulfame potassium
Gold Standard RTD Protein Shake overview
Optimum Nutrition Gold Standard RTD (Ready-to-Drink) Protein Shake is a convenient option for those on the go, offering 24 grams of protein per serving without the need for mixing or preparation. This ready-made shake comes in three flavors and is made with a blend of milk protein isolate, milk protein concentrate, and whey protein concentrate, which provides a well-rounded protein profile that supports muscle recovery and daily protein needs. (
5
,
2
) With only 130-140 calories, 2.5-3 grams of fat, and 1 gram of sugar per serving, it’s a low-calorie option suitable for a wide range of fitness goals.
In addition to its protein content, each shake provides 24 essential vitamins and minerals, including 20% of the daily value for vitamin D, vitamin A, vitamin C, vitamin E, and zinc. These nutrients help support immune function, bone health, and overall well-being, making this shake a more well-rounded option than standard protein powders that focus solely on protein content. (
6
,
7
) For those who might struggle to get enough of these vitamins through diet alone, this RTD shake can help fill nutritional gaps.
However, it’s important to note that the shake is sweetened with sucralose and acesulfame potassium, artificial sweeteners that may not appeal to everyone. Additionally, it contains carrageenan, a thickening agent that some consumers may want to avoid due to concerns about digestive irritation, though most regulatory agencies consider it safe. (
8
)
Priced at $23.99 for a 12-pack, the cost per serving is approximately $2, which is higher than traditional protein powders but less expensive than many other ready-to-drink options.
What customers are saying
Optimum Nutrition Gold Standard Ready to Drink Protein Shake has earned nearly 4,011 reviews on Amazon, with an average rating of 4.5 out of 5 stars.
Customers regularly leave positive reviews about the taste, protein content, value, and convenience of this RTD product.
“I love how this product is ready to go and allows me to enjoy a rich flavor and good texture for a protein drink. Unlike some other chalky or watered-down flavored protein drinks, this one stands out with its smooth and satisfying taste.”
Marc C., Amazon
Another customer, A. Jarrell, notes, “It tastes great and is super convenient for getting your protein on the run. You can add milk or milk alternatives, cold brew coffee, or the like to mix it up and add bulk or variety to the taste as well.”
The most common complaints on Amazon came from customers who recently received damaged or expired products.
“I ordered this on 8/21/24 and received shakes that had already expired on 6/17/24. I opened it and found that it had already grown mold or done some kind of curdling,” writes Mike L.
Who Gold Standard RTD Protein Shake is recommended for:
- Individuals who need a quick, convenient protein option on the go
- Those looking for a protein shake with added vitamins and minerals to support overall health
- Fitness enthusiasts seeking a low-calorie, low-sugar protein shake
- People who prefer ready-to-drink options over powdered protein that requires mixing
Who Gold Standard RTD Protein Shake is not recommended for:
- Athletes in tested sports, as there is no third-party testing for banned substances
- Consumers who prefer all-natural ingredients, as this shake contains sucralose, acesulfame potassium, and carrageenan
- Those who prefer to customize their protein intake or flavors, as flavor options are more limited compared to powders
- Budget-conscious individuals looking for a more affordable protein supplement option
- Individuals who are lactose intolerant or vegan
Specs
|
Protein type |
Milk protein isolate, milk protein concentrate, whey protein concentrate |
|
Calories |
130-140 |
|
Protein per serving |
24 grams |
|
Flavors |
Chocolate, strawberry, vanilla |
|
Third-party testing |
None |
|
Price per serving |
$2 |
ON Platinum Rebuild contains 24 grams of protein and 3 grams of both creatine and glutamine to support muscle growth and recovery.
Key product features
Solubility
Excellent
Low fat
1.5 grams
Third-party tested
Yes
EAAs
11 grams
Creatine
3 grams
What you should know
Optimum Nutrition Platinum Rebuild is a well-rounded protein supplement that combines multiple high-quality protein sources with creatine and glutamine for muscle recovery and growth.
-
Each serving contains 11 grams of essential amino acids (EAAs), which play an important role in muscle protein synthesis.
-
At $3 per serving, it’s a premium option, but the inclusion of creatine and glutamine makes it worth the price.
-
Best suited for athletes and fitness enthusiasts focused on muscle building, recovery, and strength gains. Plus, it’s third-party tested, making it safe for competitive athletes.
Pros
Includes 11 grams of EAAs
Contains creatine and glutamine for enhanced muscle recovery and strength
Combination of fast and slow-digesting proteins for sustained muscle support
Banned substance tested by Informed Choice
Cons
Only 20 servings per container
Platinum Rebuild overview
Optimum Nutrition Platinum Rebuild is designed for those who want more than just a standard protein shake. Each serving delivers 24 grams of protein, including 11 grams of EAAs, which are crucial for muscle repair and growth. (
3
)
What sets Platinum Rebuild apart is the inclusion of 3 grams of creatine and 3 grams of glutamine per serving.
Creatine is well-known for
its role in increasing strength and muscle mass and improving exercise performance, making it a staple for those serious about building muscle. (
9
)
“While the 3 gram dose in Platinum Rebuild offers some benefits, research often recommends a 5 gram daily intake for optimal muscle building results,” notes Pete Nastasi, CPT, CSNC. “For those aiming to maximize their gains, adding a standalone creatine supplement may be a smart choice.”
Glutamine, on the other hand, may aid in reducing muscle soreness after intense workouts, making it ideal for recovery-focused athletes. (
10
)
The protein blend in Platinum Rebuild includes micellar casein, whey protein concentrate, whey protein isolate, and hydrolyzed whey protein isolate. This combination provides both fast and slow-digesting proteins, allowing for sustained protein release. Fast-absorbing whey protein isolates help deliver quick amino acids to the muscles post-workout, while micellar casein delivers a slower release of amino acids, which is beneficial for muscle recovery over a longer period, like during sleep or extended post-workout periods. (
1
,
11
)
Platinum Rebuild also stands out due to its third-party testing through Informed Choice. This ensures that the product is free from banned substances, making it a safer option for competitive athletes. With just two flavors to choose from, it doesn’t offer the variety of other protein powders on the market.
At $59.99 for 20 servings, Optimum Nutrition Platinum Rebuild comes in at around $3 per serving. While this is on the higher end compared to standard protein powders, we think the inclusion of creatine and glutamine helps justify the price.
Who Platinum Rebuild is recommended for:
- Athletes and fitness enthusiasts focused on building muscle and improving recovery
- Those looking for a comprehensive supplement that includes creatine and glutamine
- Individuals who want a combination of fast and slow-digesting proteins for sustained muscle support
- Competitive athletes who need a product that’s third-party tested for banned substances
Who Platinum Rebuild is not recommended for:
- Budget-conscious consumers, as it comes at a higher price per serving
- Individuals who prefer a wider range of flavor options (only two flavors are available)
- People who already supplement with creatine or glutamine separately and don’t want them included in their protein powder
- Anyone following a vegan diet
- Those who are lactose intolerant
Specs
|
Protein type |
Micellar casein, whey protein concentrate, whey protein isolate, hydrolyzed whey protein isolate |
|
Calories |
130 |
|
Protein per serving |
24 grams |
|
Flavors |
Dark chocolate, vanilla buttercream |
|
Third-party testing |
Informed Choice |
|
Price per serving |
$3 |
Optimum Nutrition Platinum Hydrowhey delivers 30 grams of fast-digesting hydrolyzed whey protein isolate for rapid muscle recovery.
Key product features
Solubility
Excellent
Flavors
3 options
Third-party tested
Yes
Gluten-free
Yes
BCAAs
8.8 g
Low-fat
1 gram
What you should know
Optimum Nutrition Platinum Hydrowhey is a premium protein powder designed for rapid absorption and muscle recovery. Here’s what you should know:
-
Contains added BCAAs, though the practice of “protein spiking” may concern some users.
-
At $54.99 for 20 servings, it’s more expensive than standard whey, but offers a purer, faster-absorbing protein source.
-
Best for athletes and individuals focused on quick muscle recovery and those with sensitive digestion.
Pros
Faster absorbing and easier to digest than other forms of whey
Cons
Only available in three flavors
Platinum Hydrowhey overview
Optimum Nutrition Platinum Hydrowhey is designed for those who prioritize high-quality, fast-digesting protein to fuel muscle recovery and growth. Each serving contains 30 grams of protein from hydrolyzed whey protein isolate, one of the fastest-digesting forms of whey available.
“By breaking the protein down into smaller peptides, it enhances absorption, making it an ideal choice for post-workout recovery,” Nastsi notes. “Its rapid delivery of essential amino acids is ideal for athletes or bodybuilders who train multiple times a day and need reliable, efficient recovery to maintain peak performance.” (
12
,
13
)
The product also includes added BCAAs to support muscle repair, although it’s important to note that the added BCAAs can sometimes be considered “protein spiking,” a practice that inflates the protein content without adding complete proteins. (
3
)
Hydrolyzed whey protein is highly beneficial for those with sensitive digestive systems, as the pre-digested nature of the protein can reduce digestive discomfort often associated with other forms of whey. (
14
) At 140 calories per serving with just 1 gram of fat and 1 gram of sugar, it’s a lean option suitable for those looking to maintain a low-calorie, high-protein diet.
This product is gluten-free and has been banned substance tested through Informed Choice, making it a reliable choice for competitive athletes. However, it is sweetened with sucralose and acesulfame potassium, which may be a drawback for individuals seeking natural sweeteners. Available in only three flavors, Platinum Hydrowhey may offer limited variety compared to other protein powders on the market.
Priced at $54.99 for a 20-serving tub or $99.99 for a 40-serving tub, Platinum Hydrowhey is more expensive than standard protein powders. However, for those who value rapid protein absorption and a high-quality, pure protein source, the cost may be justified.
What customers are saying
On Amazon, Optimum Nutrition Platinum Hydrowhey has earned an average rating of 4.6 out of 5 stars from 10,000 ratings.
Most of the positive reviews focus on the taste, quality, and digestibility of this product.
“This the only protein powder I have found that doesn’t bloat me or give me gas,” writes A. Koening.
“Most [protein powders] leave me feeling bloated or sick. This does not. Love how well this mixed. Doesn’t have a grainy texture. Tastes smooth and delicious.”
Noel, Amazon
However, some customers find the use of artificial sweeteners overpowering, while others feel the product is too expensive.
“This was so sickeningly sweet it is intolerable!” notes one verified Amazon customer.
Who Platinum Hydrowhey is recommended for:
- Athletes and fitness enthusiasts focused on rapid muscle recovery post-workout
- Individuals with sensitive digestion looking for a protein that absorbs quickly and easily
- Competitive athletes who need a protein powder tested for banned substances
- Individuals who are lactose intolerant, as the hydrolyzed whey protein isolate should be virtually lactose-free
Who Platinum Hydrowhey is not recommended for:
- Budget-conscious consumers, as it’s more expensive than standard whey protein options
- People looking for a wide variety of flavor options (only three available)
- Individuals who prefer natural sweeteners, as this product contains sucralose and acesulfame potassium
- Individuals with a dairy allergy or those who follow a vegan diet
Specs
|
Protein type |
Hydrolyzed whey protein isolate, BCAAs |
|
Calories |
140 |
|
Protein per serving |
30 grams |
|
Flavors |
Supercharged strawberry, turbo chocolate, velocity vanilla |
|
Third-party testing |
Informed Choice |
|
Price per serving |
$2.50- $2.75 |
Optimum Nutrition Gold Standard 100% Isolate contains 25g of pure whey protein isolate and minimal fat and sugar.
Key product features
Solubility
Excellent
Third-party tested
Yes
Gluten-free
Yes
BCAAs
5.5 g
Low fat
< 1 gram
What you should know
Optimum Nutrition Gold Standard 100% Isolate provides 25 grams of fast-digesting whey protein isolate per serving, ideal for lean muscle recovery.
-
Optimum Nutrition is a highly reputable sports nutrition brand. This protein powder is banned substance tested through Informed Choice for added safety and reliability.
-
At $46.99 for 24 servings, it’s slightly pricier, but the high protein purity offers solid value for the investment.
-
The minimal fat and sugar content makes it an excellent option for those aiming to maintain a clean, low-calorie diet.
Pros
5.5 grams of naturally occurring BCAAs to support muscle recovery
Whey protein isolate is easier to digest than whey protein concentrate
Cons
Only available in two flavors
Contains artificial sweeteners
Gold Standard 100% Isolate overview
Optimum Nutrition Gold Standard 100% Isolate is a low-calorie protein option designed for those looking to support muscle recovery and growth with minimal fat and sugar. Each serving provides 25 grams of protein from whey protein isolate, one of the purest forms of protein, which is quickly absorbed by the body to support muscle recovery post-exercise. (
15
) Additionally, each serving offers 5.5 grams of naturally occurring BCAAs, which are essential for muscle repair and reducing exercise-induced muscle damage. (
3
)
This product is third-party tested through Informed Choice, making it a safe choice for athletes in tested sports. Depending on the flavor, the calorie count ranges between 100 and 110 per serving, with the rich vanilla flavor containing 0 grams of fat and the chocolate bliss flavor containing 0.5 grams. With only 1 gram of sugar per serving, it’s a suitable choice for those aiming to maintain a low-sugar diet.
While the product delivers on protein purity and effectiveness, it comes in just two flavors, which might limit the appeal for those who prefer a variety. The formula is sweetened with sucralose, which keeps the sugar content low but may not be preferred by consumers who avoid artificial sweeteners.
Priced at $46.99 for 24 servings or $72.99 for 44 servings, Gold Standard Isolate is slightly more expensive than regular whey protein products but reflects the premium nature of whey protein isolate, which undergoes additional processing to remove fat and lactose. For individuals seeking a high-quality, fast-digesting protein with minimal additives, this product offers great value despite the limited flavor options.
What customers are saying
Optimum Nutrition Gold Standard 100% Isolate has a 4.6 out of 5-star rating on Amazon. Top reviews focus on the taste, solubility, and digestibility of this protein powder.
“This is great tasting, easily mixable, and gentle on the stomach,”
Max, Amazon
Another Amazon buyer named T. Kim adds, “My stomach feels fine, and it tastes great.”
Some of the negative reviews came from customers who said the product arrived damaged or expired.
Who Gold Standard 100% Isolate is recommended for:
- Consumers who prioritize minimal additives in their protein supplements
- Individuals following a low-calorie or low-fat diet, as this product is low in fat and sugar
- Those needing a gluten-free protein option
- Athletes and fitness enthusiasts seeking fast-absorbing protein to support lean muscle growth
- Individuals who are lactose intolerant and can’t digest whey protein concentrate
Who Gold Standard 100% Isolate is not recommended for:
- People who prefer a wide variety of flavors, as only two flavors are available
- Budget-conscious consumers, as it’s priced higher than other whey protein options, like whey protein concentrate
- Individuals looking for natural sweeteners, as this product contains sucralose
- Anyone with a dairy allergy or who follows a vegan diet
Specs
|
Protein type |
Hydrolyzed whey protein isolate, whey protein isolate |
|
Calories |
100-110 |
|
Protein per serving |
25 grams |
|
Flavors |
Chocolate bliss, rich vanilla |
|
Third-party testing |
Informed Choice |
|
Price per serving |
$1.66- $1.96 |
ON Gold Standard 100% Casein provides 24 grams of slow-digesting micellar casein protein, ideal for overnight muscle recovery.
Key product features
Flavors
4 options
Third-party tested
Yes
EAAs
9 grams
Low-fat
1 gram or less
What you should know
Optimum Nutrition Gold Standard 100% Casein is a slow-digesting protein designed to support extended muscle recovery. Third-party testing through Informed Choice ensures quality and safety.
-
Although it mixes well, casein doesn’t fully dissolve in liquid. Our product tester loves using the chocolate supreme flavor to make protein pudding.
-
At $53.99 for 25 servings, it’s priced higher than many standard protein powders but is competitive with other high-quality casein products, which typically range between $2 and $2.50 per serving.
-
Best for individuals looking to maintain muscle mass overnight or between meals with slow-digesting protein.
Pros
Slow-digesting protein is ideal for overnight recovery
Contains 9 g of EAAs to support muscle repair
Cons
Doesn’t fully dissolve in liquid, resulting in a thicker texture.
Gold Standard 100% Casein overview
Optimum Nutrition Gold Standard 100% Casein is designed for individuals looking for a slow-digesting protein to support muscle recovery over extended periods, such as during sleep. Each serving contains 24 grams of protein from micellar casein, a slower-digesting protein compared to whey. This makes it beneficial for those who want a steady release of amino acids over several hours, ideal for preventing muscle breakdown overnight or between meals. (
11
)
In addition to its 24 grams of protein, the product offers 9 grams of EAAs per serving, further supporting muscle repair and growth. (
3
) Each serving contains 110-120 calories, 0.5-1 gram of fat, and 1-2 grams of sugar, depending on the flavor.
Sweetened with acesulfame potassium and sucralose, the product offers a balanced macronutrient profile for those who want to keep sugar and fat intake low. With four available flavors, users have some variety, though fewer options compared to other protein types.
“Both the chocolate peanut butter and chocolate supreme are incredibly smooth and delicious. Because casein gets really thick, I use the chocolate supreme flavor to make protein pudding. It tastes almost as good as real chocolate pudding.”
Team Product Tester
Gold Standard Casein is third-party tested through Informed Choice, which ensures the quality and purity of its ingredients and makes it suitable for competitive athletes. At $53.99 for 25 servings or $91.99 for 53 servings, it is a higher-priced option, but for individuals looking for a slow-release protein to support long-term muscle recovery, the cost may be well worth it.
What customers are saying
On Amazon, Optimum Nutrition Gold Standard 100% Casein has earned a 4.6 out of 5-star rating from nearly 17,000 reviews.
Customers regularly leave positive comments about the taste, quality, and value of this product.
“I’ve been using this for a few years. It’s one of the best protein products I’ve tried.”
Mike, Amazon
Another customer named Erika notes, “This protein is of great quality. It’s easy to consume and keeps me full!”
However, some customers aren’t a fan of the texture or the taste of the artificial sweeteners.
“Casein cookies and cream flavor is NOT good,” writes an Amazon buyer with the username F.C.
Who Gold Standard 100% Casein is recommended for:
- Athletes and fitness enthusiasts looking for a slow-digesting protein to support overnight recovery
- Individuals aiming to prevent muscle breakdown between meals or during fasting periods
- Those who prefer a thicker texture in their protein shakes or enjoy making protein-rich snacks like pudding
- Competitive athletes who need a third-party tested protein powder for safety and banned substance certification
Who Gold Standard 100% Casein is not recommended for:
- Individuals on vegan or dairy-free diets, as casein is derived from milk
- Those looking for a protein powder that dissolves easily in liquids, as casein tends to be thicker
- Budget-conscious consumers, as it’s more expensive than standard whey protein
- People who avoid artificial sweeteners, as it contains acesulfame potassium and sucralose
Specs
|
Protein type |
Micellar casein |
|
Calories |
110-120 |
|
Protein per serving |
24 grams |
|
Flavors |
Chocolate peanut butter, chocolate supreme, cookies & cream, creamy vanilla |
|
Third-party testing |
Informed Choice |
|
Price per serving |
$1.74-$2.16 |
Optimum Nutrition Gold Standard 100% Plant provides 24 grams of protein and all nine essential amino acids.
Key product features
Vegan
Yes
Sweetener
Stevia
Low-sugar
0 grams
What you should know
Optimum Nutrition Gold Standard 100% Plant offers a clean, plant-based protein option with no artificial colors, flavors, or sweeteners. Here’s what you should know:
-
The blend of pea, fava bean, and brown rice protein offers a more complete amino acid profile than single-source plant proteins.
-
At $1.85-$2 per serving, it’s competitively priced compared to other high-quality plant-based protein powders on the market.
-
Ideal for vegans or anyone looking for a dairy-free, plant-based protein option with all essential amino acids.
Pros
Made from a blend of plant-based protein sources to provide a complete amino acid profile
Contains all nine essential amino acids
No artificial colors, flavors, or sweeteners
Cons
Lacks a detailed amino acid profile, making it hard to assess leucine content
Gold Standard 100% Plant overview
Optimum Nutrition Gold Standard 100% Plant is a vegan-friendly protein powder made from a blend of pea protein, fava bean protein isolate, and brown rice protein concentrate. Using a blend of these plant-based proteins provides a more complete amino acid profile than relying on a single source, as different plant proteins vary in their amino acid content. (
16
,
17
,
18
)
Each serving contains 24 grams of protein and 150 calories, with 0 grams of sugar and 3.5 grams of fat. While it would be helpful to know the full amino acid profile—particularly the leucine content, as leucine is key for stimulating muscle protein synthesis—this information is not provided. Leucine is one of the most important amino acids for building muscle, and its quantity could make a difference in the overall effectiveness of the product. (
19
)
Unlike many of Optimum Nutrition’s other products, this one is sweetened with stevia, making it a sugar-free option. It is available in only two flavors, which may limit variety for some consumers.
We do appreciate that Optimum Nutrition’s Gold Standard 100% Plant is Informed Choice certified, ensuring a high quality.
In terms of cost, the 12-serving tub is priced at $23.99, while the 20-serving tub is $36.99, breaking down to about $2 and $1.85 per serving, respectively. This price is on par with many other high-quality plant-based protein powders.
What customers are saying
On Amazon, customers regularly leave positive reviews about Optimum Nutrition Gold Standard 100% Plant. This product has earned 4.1 out of 5 stars from 1,419 ratings.
Customers like the quality, ingredients, and protein content.
“It’s a hit in our household– my husband and son are lactose intolerant, so we only use vegan protein and have tried a multitude of plant-based proteins. The taste, the quality of ingredients, and the price point can’t be beat.”
Vanessa, Amazon
Alyssa R., who purchased the rich chocolate fudge flavor, agrees. “I have tried many plant protein powders, but this one truly stands out. The taste is absolutely delicious without any of the chalky aftertaste that is common in other powders. It’s smooth, easy to mix, and perfect for my post-workout shakes. On top of that, the price is fantastic for the quality you’re getting.”
One of the most common complaints about this product is that the plastic tub is only half-filled, which customers feel is wasteful. A few customers didn’t like the taste or texture when comparing it to whey products.
“I have been using the vanilla ice cream whey protein from the same brand, and that stuff is fantastic. I’ve been trying to go plant-based, so I thought I would try this out. It’s absolutely horrible. It tastes like a mix of chalk and dirt with a pinch of vanilla,” says Gabriella W.
Who Gold Standard 100% Plant is recommended for:
- Individuals following a vegan or plant-based diet seeking a high-protein supplement
- Those looking for a protein powder with no artificial colors, flavors, or sweeteners
- People with dairy sensitivities or lactose intolerance who need a clean, plant-based option
- Consumers prioritizing a sugar-free protein supplement, as it’s sweetened with stevia
Who Gold Standard 100% Plant is not recommended for:
- Consumers who prefer a wide variety of flavor options, as this product is limited to two flavors
- Those seeking a protein powder with a detailed amino acid profile, especially for leucine content
- People who prefer whey or animal-based proteins for quicker absorption and muscle recovery
Specs
|
Protein type |
Pea protein, fava bean protein isolate, brown rice protein concentrate |
|
Calories |
150 |
|
Protein per serving |
24 grams |
|
Flavors |
Creamy vanilla, rich chocolate fudge |
|
Third-party testing |
Informed Choice |
|
Price per serving |
$1.85-$2 |
How we test whey protein supplements
Whey protein is a widely-used form of protein. However, with various types of whey protein available, each offering unique benefits and applications, choosing the right one can be difficult.
Our team developed a comprehensive testing methodology and scoring algorithm to identify the best whey protein products on the market. Our evaluation covers six primary categories: protein source, macronutrient calories per serving, protein per serving, price per gram of protein, sweeteners, and third-party testing. Products can earn additional bonus credits to enhance their overall rating. These categories were developed in collaboration with registered dietitian and doctor of exercise physiology,
Chris Mohr
.
You can read
our full whey protein testing methodology here
.
Protein source–50%
This makes up the bulk of our evaluation, since whey protein powder formula impacts its digestibility, absorption, and ration of protein to other macronutrients. We evaluate four different whey protein sources: whey concentrate, whey isolate, whey hydrolysate, and whey blends.
Total protein per serving–20%
Macronutrient calories per serving–15%
The majority of calories in whey protein powders should come from protein. Calories may also come from carbohydrates and fats, depending on a protein product’s ingredients.
Cost per serving–5%
Price often reflects quality—but not always. We rate whey protein powders based on their price per gram of protein
Sweeteners–10%
We prefer products with minimal sweeteners and rate them according to their nutritional profile.
Certifications
Certifications provide a small boost to the product’s overall score and are equally weighted.
Here are the certifications that stand out:
-
Third-party testing
-
Informed Choice (ICFS)
-
NSF
-
U.S. Pharmacopeia (USP)
-
Labdoor
Bonus points
To recognize innovation and encourage healthy competition, we incorporate bonus credits into our scores. Here are some ways products can earn bonus points:
-
Enzymes for digestion
-
Sustainable packaging
-
100% grass-fed whey
-
Certified organic
-
No proprietary blends
How we test plant-based protein supplements
Plant protein is a popular alternative to whey protein in dietary supplements. While not all plant protein sources are complete proteins (containing all nine essential amino acids), most plant protein blends include at least one complete protein source.
We evaluate plant protein powders across six categories: protein source, completeness of the protein, macronutrient calories per serving, protein per serving, price per gram of protein, and sweeteners. These categories were also developed in collaboration with
Chris Mohr
, Ph.D., RD.
You can read
our full plant-based protein testing methodology here
.
Protein source–40%
The protein sources in a plant protein powder determine whether it’s a complete protein source. The source(s) also determine the calories from protein versus carbohydrates or fats. We evaluate eight plant protein sources: soy, pea, hemp, brown rice, lentil, chia, pumpkin seed, and blends.
Complete protein–20%
To be considered complete proteins, protein supplements have to consistently provide all nine essential amino acids, which are necessary for supporting muscle growth and overall development. Therefore, complete proteins receive the highest marks.
Macronutrient calories per serving–15%
Ideally, most of the calories consumed through plant protein powder should come from protein. However, depending on the protein source and other ingredients, calories can also come from carbohydrates and fats.
Total protein per serving–15%
Daily protein needs vary by individual but, in general, 25-30 grams per meal, and additional in snacks, meets the needs of most people. Most plant protein supplements contain around 15-30 grams of protein per serving.
Price per gram of protein–5%
Price is an important factor for consumers and often (though not always) reflects the quality of a product. Since protein content is the best measure of value for a plant protein powder, we rate each product based on the price per gram of protein.
Sweeteners–5%
We prefer to see minimal sweeteners in plant protein formulas, and we prefer some over others.
Certifications
Nearly all reputable supplement companies conduct in-house testing for safety and label accuracy. However, many brands also opt for additional certifications to further ensure quality and safety. We award bonus credits to brands that undertake this additional step.
Bonus points
We incorporate bonus credits into our plant-based protein supplement scores to recognize innovation and encourage healthy competition among all brands. Plant protein formulas are awarded bonus credits for:
-
No proprietary blends
-
Sustainable packaging
-
Added enzymes
Gold Standard 100% Whey vs. competitors
FAQs
Is Optimum Nutrition whey protein any good?
Yes, Optimum Nutrition whey protein is widely regarded as a high-quality protein supplement. It provides a blend of whey protein isolate, concentrate, and hydrolyzed whey, delivering 24 grams of protein per serving and is third-party tested for banned substances. Its taste, mixability, and broad flavor options also contribute to its positive reputation.
How pure is Optimum Nutrition whey protein?
Optimum Nutrition whey protein, especially in the Gold Standard line, is known for its purity. It uses whey protein isolate as its primary ingredient, which is one of the purest forms of whey. The product is also third-party tested through Informed Choice, ensuring there are no banned substances.
Is Optimum Nutrition 100% Whey Gold Standard good for muscle building?
Yes, Optimum Nutrition 100% Whey Gold Standard is effective for muscle building. Each serving provides 24 grams of high-quality protein, including 5.5 grams of naturally occurring BCAAs, which support muscle recovery and growth after workouts. (
20
) Its fast-absorbing whey protein isolate makes it ideal for post-exercise nutrition.
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any diseases.
Our experts
Pete Nastasi, CPT, CSNC
Pete Nastasi is a NASM-certified sports nutrition coach, personal trainer, and the owner of N2 Nutrition and Performance. Pete helps individual clients achieve their sports performance and weight-loss goals through a personalized approach centered around diet optimization, easy-to-follow workout routines, and healthy lifestyle habits.
Joana Neziri, M.S., NASM CPT
Joana is a writer, editor, and content strategist focusing on nutrition, fitness, and all things health. After earning a master’s degree in business from the University of North Florida, she began a career in research and digital marketing.
Lily Moe
Lily is a Brooklyn-based writer and editor with over seven years of experience in health media. As a former Fitness Coach, Lily’s editorial prowess has largely focused on fitness, nutrition, and weight management. She has also spent a fair share of time in testing labs, analyzing everything from protein powders to yoga mats. Her work has appeared in Verywell Fit, Verywell Mind, Health, and more.
Kelly Uhler
Kelly has a multifaceted background in elder care, health care, and copywriting. She has worked for organizations such as A Place For Mom and Homecare.com, which gave her the opportunity to work closely with families, providing reliable information to help them make informed decisions about their loved one’s health, safety, and quality of life.
Melissa Boufounos, CHN
Fortune Recommends Nutrition Writer
About Author
Sources
-
-
Zhou, H., Liao, Y., Zhou, X., Peng, Z., Xu, S., Shi, S., Liu, L., Hao, L., & Yang, W. (2024). Effects of Timing and Types of Protein Supplementation on Improving Muscle Mass, Strength, and Physical Performance in Adults Undergoing Resistance Training: A Network Meta-Analysis. International Journal of Sport Nutrition and Exercise Metabolism, 34(1), 54-64. Retrieved Sep 20, 2024, from
https://doi.org/10.1123/ijsnem.2023-0118
-
Arentson-Lantz, E. J., & Kilroe, S. (2021). Practical applications of whey protein in supporting skeletal muscle maintenance, recovery, and reconditioning. Journal of animal science, 99(4), skab060.
https://doi.org/10.1093/jas/skab060
-
Church, D. D., Hirsch, K. R., Park, S., Kim, I. Y., Gwin, J. A., Pasiakos, S. M., Wolfe, R. R., & Ferrando, A. A. (2020). Essential Amino Acids and Protein Synthesis: Insights into Maximizing the Muscle and Whole-Body Response to Feeding. Nutrients, 12(12), 3717.
https://doi.org/10.3390/nu12123717
-
Zaromskyte, G., Prokopidis, K., Ioannidis, T., Tipton, K. D., & Witard, O. C. (2021). Evaluating the Leucine Trigger Hypothesis to Explain the Post-prandial Regulation of Muscle Protein Synthesis in Young and Older Adults: A Systematic Review. Frontiers in Nutrition, 8, 685165.
https://doi.org/10.3389/fnut.2021.685165
-
Huang, L. P., Condello, G., & Kuo, C. H. (2021). Effects of Milk Protein in Resistance Training-Induced Lean Mass Gains for Older Adults Aged ≥ 60 y: A Systematic Review and Meta-Analysis. Nutrients, 13(8), 2815.
https://doi.org/10.3390/nu13082815
-
Munteanu, C., & Schwartz, B. (2022). The relationship between nutrition and the immune system. Frontiers in nutrition, 9, 1082500.
https://doi.org/10.3389/fnut.2022.1082500
-
Rizzoli, R., Biver, E., & Brennan-Speranza, T. C. (2021). Nutritional intake and bone health. The lancet. Diabetes & endocrinology, 9(9), 606–621.
https://doi.org/10.1016/S2213-8587(21)00119-4
-
Komisarska, P., Pinyosinwat, A., Saleem, M., & Szczuko, M. (2024). Carrageenan as a Potential Factor of Inflammatory Bowel Diseases. Nutrients, 16(9), 1367.
https://doi.org/10.3390/nu16091367
-
Kreider, R. B., Kalman, D. S., Antonio, J., Ziegenfuss, T. N., Wildman, R., Collins, R., Candow, D. G., Kleiner, S. M., Almada, A. L., & Lopez, H. L. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 14, 18.
https://doi.org/10.1186/s12970-017-0173-z
-
Córdova-Martínez, A., Caballero-García, A., Bello, H. J., Pérez-Valdecantos, D., & Roche, E. (2021). Effect of Glutamine Supplementation on Muscular Damage Biomarkers in Professional Basketball Players. Nutrients, 13(6), 2073.
https://doi.org/10.3390/nu13062073
-
Kim J. (2020). Pre-sleep casein protein ingestion: new paradigm in post-exercise recovery nutrition. Physical activity and nutrition, 24(2), 6–10.
https://doi.org/10.20463/pan.2020.0009
-
Morgan, P. T., & Breen, L. (2021). The role of protein hydrolysates for exercise-induced skeletal muscle recovery and adaptation: a current perspective. Nutrition & metabolism, 18(1), 44.
https://doi.org/10.1186/s12986-021-00574-z
-
Nakayama, K., Tagawa, R., Saito, Y., & Sanbongi, C. (2019). Effects of whey protein hydrolysate ingestion on post-exercise muscle protein synthesis compared with intact whey protein in rats. Nutrition & metabolism, 16, 90.
https://doi.org/10.1186/s12986-019-0417-9
-
Sun, Y., Ling, C., Liu, L., Zhang, J., Wang, J., Tong, X., Hidayat, K., Chen, M., Chen, X., Zhou, H., Xu, J., Qin, L., Zhu, W., & Yang, J. (2022). Effects of Whey Protein or Its Hydrolysate Supplements Combined with an Energy-Restricted Diet on Weight Loss: A Randomized Controlled Trial in Older Women. Nutrients, 14(21), 4540.
https://doi.org/10.3390/nu14214540
-
Kim, C. B., Park, J. H., Park, H. S., Kim, H. J., & Park, J. J. (2023). Effects of Whey Protein Supplement on 4-Week Resistance Exercise-Induced Improvements in Muscle Mass and Isokinetic Muscular Function under Dietary Control. Nutrients, 15(4), 1003.
https://doi.org/10.3390/nu15041003
-
Singh, R. G., Guérin-Deremaux, L., Lefranc-Millot, C., Perreau, C., Crowley, D. C., Lewis, E. D., Evans, M., & Moulin, M. (2024). Efficacy of Pea Protein Supplementation in Combination with a Resistance Training Program on Muscle Performance in a Sedentary Adult Population: A Randomized, Comparator-Controlled, Parallel Clinical Trial. Nutrients, 16(13), 2017.
https://doi.org/10.3390/nu16132017
-
Martineau-Côté, D., Achouri, A., Karboune, S., & L’Hocine, L. (2022). Faba Bean: An Untapped Source of Quality Plant Proteins and Bioactives. Nutrients, 14(8), 1541.
https://doi.org/10.3390/nu14081541
-
Moon, J. M., Ratliff, K. M., Blumkaitis, J. C., Harty, P. S., Zabriskie, H. A., Stecker, R. A., Currier, B. S., Jagim, A. R., Jäger, R., Purpura, M., & Kerksick, C. M. (2020). Effects of daily 24-gram doses of rice or whey protein on resistance training adaptations in trained males. Journal of the International Society of Sports Nutrition, 17(1), 60.
https://doi.org/10.1186/s12970-020-00394-1
-
Lim, C., Janssen, T. A., Currier, B. S., Paramanantharajah, N., McKendry, J., Abou Sawan, S., & Phillips, S. M. (2024). Muscle Protein Synthesis in Response to Plant-Based Protein Isolates With and Without Added Leucine Versus Whey Protein in Young Men and Women.
Current developments in nutrition
,
8
(6), 103769.
https://doi.org/10.1016/j.cdnut.2024.103769
-
Khemtong C, Kuo CH, Chen CY, Jaime SJ, Condello G. Does Branched-Chain Amino Acids (BCAAs) Supplementation Attenuate Muscle Damage Markers and Soreness after Resistance Exercise in Trained Males? A Meta-Analysis of Randomized Controlled Trials. Nutrients. 2021 May 31;13(6):1880. doi: 10.3390/nu13061880. PMID: 34072718; PMCID: PMC8230327.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8230327/
-
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