The 8 Best Casein Protein Powders (2024): High-Quality Options Reviewed by a Registered Dietitian

Adequate rest and protein intake are the pillars of muscle growth, especially when applying progressive overload on a regular basis. This might make casein protein powder—often called the “sleep protein”—the ultimate synergist for taking your fitness goals to the next level. That’s because casein digests slower than whey protein, so it keeps you fuller for longer—such as when you’re asleep.

Don’t just take our word for it! A 2020 systematic review published in Physical Activity and Nutrition¹ suggests that pre-sleep casein intake might facilitate muscle recovery after a bout of resistance exercise. If your interest is piqued, join us as we explore what casein is and its potential benefits. We’re also revealing the best casein protein powder supplements you shouldn’t be sleeping on! 

Our team of competitive triathletes, weightlifting coaches, and registered dietitians might have started with gym equipment reviews, but we also know what it takes to fuel your training and recover from it, too. We look at five main factors when reviewing the best protein powder for your fitness needs:

• Formulation: Does it have the right ingredients and avoid unnecessary fillers?
• Macros: What does it protein, carb, and fat content look like? Does it have at least 20 grams of protein?
• Taste: Subjective, but we wanted to make sure we and other customers could stomach it
• Price: How much does it cost?

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.

Best Casein Protein Powder for 2024

• Best Casein Protein Powder Overall: Transparent Labs Casein Protein
• Best-Tasting Casein Protein Powder: Legion Athletics Casein+
• Best Whey Casein Protein Blend: Muscle Feast Premium Whey Casein Blend
• Best Unflavored Casein Protein: NOW Sports Unflavored Casein Protein Powder
• Best Casein Protein for Baking: Dymatize Elite Casein
• Best Gluten-Free Casein Protein: Ascent Native Fuel Micellar Casein
• Best Grass-Fed Casein Protein: Naked Nutrition Naked Casein Protein
• Best Budget Casein Protein Powder: Optimum Nutrition 100% Gold Standard Casein

An Open Case(in): What to Know Before Trying Casein Protein Powder

Before diving into our top casein picks, let’s open the case of what casein is and how it compares to whey. Thanks to the nursery rhyme that says, “Little Miss Muffet sat on her tuffet, eating her curds and whey,” we’ve all likely been introduced to casein at an early age—yep, those “curds” are actually casein proteins.

Casein and whey are types of protein powder that come from cow’s milk and are considered complete proteins, meaning they contain all essential amino acids. Casein is the predominant protein in cow’s milk and makes up about 80% of its total protein content. 

The milk proteins are produced during cheese production, in which acids or enzymes are added that cause the casein to coagulate into curds and separate from the liquid whey. Recognizing that casein forms into curds and whey is left as the watery liquid can also be helpful for understanding their key difference: absorption rate. 

Whey protein is fast-acting and absorbed quickly, similar to how liquid can pass through the gut quite quickly. On the other hand, casein—also nicknamed “slow protein”—curdles during digestion, prolongs the absorption process, and adds to the benefits of casein protein powder (more on that near the end, so be sure to stick with us).

Casein Protein Powders 

After casein and whey are separated from one another, they are washed and dried for use in food products or protein powders: so either whey, casein, or mixes of these make up protein powders. 

Casein protein powders mostly contain micellar casein or casein micelles, which are naturally-formed aggregates and are considered to be the least processed version of casein. Casein micelles are rich in protein and calcium, as well as magnesium and phosphorus in smaller amounts. 

Casein may also be produced and processed into casein hydrolysate via hydrolysis—a digestive process that breaks down proteins into smaller peptides or amino acid chains. Research published in The American Journal of Clinical Nutrition² tells us that protein hydrolysates are digested more quickly compared to intact proteins, which would make casein hydrolysate more comparable to whey protein powder.

While both forms of casein have their time and place, we’ll be focusing on casein in its purest micellar form. That all said, let’s hop into our top casein picks!

Compare Side By Side

	Transparent Labs Casen	Legion Casein+	Muscle Feast Premium Blend Protein	NOW Casein	Dymatize Casein	Ascent Casein Powder	Naked Nutrition Casein	Optimum Casein
Rating Our expert product testers, who include certified personal trainers and coaches, use a multi-point testing methodology to determine average ratings out of 5 stars.						Coming Soon
Price Per Serving	$1.99	$2.00	$1.31 – $1.76	$1.32	$1.71	$1.70	$1.67	$1.74 – $2.16
Protein Per Serving	25 g	26 g	21 g	19 g	25 g	25 g	26 g	24 g
Type	Casein protein	Micellar casein	Micellar casein and whey protein	Micellar casein	Micellar casein	Micellar casein	Micellar casein	Casein protein
Third-party Tested?			—
Calories Per Serving	120	110	90	130	130	110	130	110 – 120
Flavors	1 flavor	4 flavors	3 flavors	Unflavored	4 flavors	3 flavors	3 flavors	4 flavors
	Check Price	Check Price	Check Price	Check Price	Check Price	Check Price	Check Price	Check Price

Best Casein Protein Powder Overall: Transparent Labs Casein Protein

Good for: Anyone searching for casein protein formulated with high-quality and natural ingredients

Best Overall

Transparent Labs Casein Protein

GGR Score: 4.18

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Product Highlights

• 100% grass-fed casein protein 
• 3rd-party lab tested 
• Chocolate flavor

Pros & Cons

Pros

• Subscribe and save 10%
• No artificial sweeteners, coloring, or preservatives
• 3rd-party lab tested
• Transparent ingredients
• Extremely positive reviews on taste
• More delicious and less clumpy than other casein protein powders, according to our product tester

Cons

• Only available in 1 flavor
• May be sold out
• Comparably expensive
• Limited reviews

Bottom Line

Transparent Labs Casein Protein provides 25 grams of protein per scoop and is extremely popular among users. Unfortunately, it may be sold out when you try to buy it, but you can sign up to be notified when it is available again.

Because Transparent Labs takes pride in transparency, it’s not so surprising they focus on sourcing only high-quality and pure ingredients. In fact, the Transparent Labs Whey Protein Isolate is featured on our best protein powder list. The Transparent Labs Casein Protein is no different, as its casein protein is also sourced from 100% grass-fed cattle.

The protein powder provides 25 grams of protein per serving sourced by instantized micellar casein protein. And since casein protein is slow-acting, they suggest their blend is the ideal nighttime protein powder to promote both satiety and a slow release of amino acids.

Transparent Labs also suggests drinking 1 to 3 scoops daily, although we still encourage you to focus on consuming high-protein foods. Of course supplements can and do have their time and place, but protein powders often lack other nutritional and health benefits that whole foods provide.

In regards to taste and mixability, former GGR senior fitness writer and certified sports nutrition coach Amanda Capritto gave it a 5 out of 5 in our Transparent Labs Casein Protein review. “Once upon a time, when I was obsessed with clean eating and macros, I learned to make pudding with casein. All you do is mix it with less liquid than usual. Let me tell you: This stuff tastes damn near like Jell-O chocolate pudding out of the little plastic tubs when mixed to mimic pudding. It’s so good! I actually crave this.”

The casein protein is also free of added sugars, fillers, and so-called “artificial junk” like artificial sweeteners, coloring, and preservatives. Instead, the casein product is naturally sweetened and flavored with cocoa powder, Himalayan rock salt, and stevia extract.

Like all Transparent Labs products, you can even view the protein’s Certificates of Analysis and Composition that truly capture their commitment to transparency. And while it goes without saying, all Transparent Lab products are third-party lab tested. 

Best-Tasting Casein Protein Powder: Legion Casein+

Good for: Those who want a casein protein powder that tastes like a milkshake

Best Tasting

Legion Athletics Casein+ Protein Powder

GGR Score: 4

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Product Highlights

• Milk-derived casein protein powder
• Thick texture
• 5 flavor options
• Sourced from grass-fed cattle
• 25 g protein per serving 
• 5 grams of BCAAs and 11.4 grams of EAAs per serving

Pros & Cons

Pros

• Sourced from grass-fed cattle
• 100% micellar casein
• Tasty flavor options
• Smooth, rich, creamy texture
• Analyzed for purity and potency in an ISO 17025 accredited lab
• 0g added sugar
• Includes BCAAs and EAAs
• Subscribe-and-save option

Cons

• Casein protein is significantly thicker than whey
• Casein can cause bloating and gas, especially upon initial use
• Takes quite a bit of shaking to get rid of all clumps

Bottom Line

Legion Athletics Casein+ Protein Powder comes in several delicious flavors, and we’re fans of the Banana Cream Pie. Casein can be consumed as a shake, or with less water, like a pudding. This protein has 25 grams of protein per 110-calorie serving.

Certified personal trainer and GGR performance editor Anthony O’Reilly tried close to 10 casein protein powders before declaring Legion Athletics Casein+ his favorite on the flavor front. He gave the Banana Cream Pie flavor a 4 out of 5 on taste—his only complaint is it didn’t remind him of the famous dessert. “It tasted more like a slightly underripe banana to me, which isn’t necessarily a bad thing,” Anthony says. “It’s still very, very good. It’s sweet enough that it scratches the urge for a dessert-like protein powder.”

Legion Athletics Casein+ is a no-sugar-added micellar casein protein powder made with pure Truly Grass Fed™ casein protein. Truly Grass Fed™ refers to milk sourced from family farms in Ireland, in which the hormone and antibiotic-free cattle are raised outdoors with the freedom to roam and graze on the pasture.

The casein protein provides only 3 grams of carbs without any added refined sugars, such as sucrose and corn syrup, and artificial sweeteners. Each flavor—like Banana Cream Pie, Cinnamon Cereal, and Dutch Chocolate—is naturally flavored and sweetened with stevia and monk fruit.

Truly Grass Fed™ milk is what provides each serving with 26 grams of protein and about 5 grams of branched-chain amino acids. Legion also claims Casein+ is the highest quality casein you can buy and has a “stellar” amino acid profile, specifically providing 11.4 grams of essential amino acids per serving. 

Truly Grass Fed™ milk is what provides each serving with 26 grams of protein and about 5 grams of branched-chain amino acids. Legion also claims Casein+ is the highest quality casein you can buy and has a “stellar” amino acid profile, specifically providing 11.4 grams of essential amino acids per serving. 

Along with being sugar-free, Legion is free from any B.S., and we truly commend their honesty. I mean, look what’s written on their casein protein powder’s product page:

So not only are they not making artificial claims to make a buck, but they are so confident in their product, that they’ll give you your money back if you aren’t a satisfied casein consumer. Oh, and apparently you only have to let Legion know if you don’t absolutely love their product for the money-back guarantee—yep, no forms or returns are necessary.

And to place the cherry on top, the casein protein is made in the U.S. in NSF-certified, FDA-inspected, and cGMP-compliant facilities. It’s also third-party lab tested for potency and purity—meaning analyzed for (and free of) heavy metals, microbes, allergens, and other contaminants—with the latest lab results available for your viewing online. 

Anthony loves this for days he’s doing intermittent fasting or if he needs a few calories before going to bed for the night.

Best Whey Casein Protein Blend: Muscle Feast Premium Whey Casein Blend

Good for: Anyone who wants to combine slow and fast-digesting properties into one protein powder

Best Whey Casein Blend

Muscle Feast Premium Blend Protein

GGR Score: 3.5

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Product Highlights

• Blend of whey and casein protein 
• 21 g of protein per serving 
• Gluten-free, kosher, non-GMO, vegetarian, no artificial ingredients 
• No factory farmed ingredients

Pros & Cons

Pros

• No factory farmed ingredients
• 30-day money back guarantee
• No artificial ingredients or fillers
• 3 flavors available including unflavored

Cons

• Limited reviews
• Bitter taste due to hydrolyzed whey protein
• Customers don’t love taste

Bottom Line

Muscle Feast Premium Blend Protein combines casein and whey to provide 21 grams of protein for both fast and slow absorption.

Muscle Feast Premium Whey Casein Blend is the one and only casein protein on our list that provides both whey and casein. Together, the premium blend of proteins—featuring whey isolate, hydrolyzed whey, and micellar casein—helps maximize muscle protein synthesis and minimize recovery times. 

RELATED: Best Muscle Recovery Supplements 

Competitive weightlifter and GGR senior director of content Kate Meier gave this protein a 3 out of 5 on taste—it wasn’t bad, but she didn’t get much flavor from the Chocolate flavor. “I actually thought maybe I’d gotten the unflavored instead and had to check the label,” Kate says. “It certainly isn’t a bad taste by any means; just not much of a taste.”

Recall that whey protein is absorbed faster than casein, which makes it attractive for situations of metabolic stress—including those caused by physical exercise, muscle mass loss, neurological disorders, and immune deficiencies—explains a study published in Food Research International.³ BCAA concentrations (especially leucine) are also higher in whey protein, which may boost muscle protein synthesis and recovery. 

Rather than isolating whey and casein, research⁴ suggests consuming them together may be ideal for optimizing an anabolic, muscle-building environment. This is because you could get an immediate dose from whey, which is then sustained for a few hours thanks to casein. 

Beyond the function of the ingredients, Muscle Feast is committed to and proud of providing a natural protein blend sourced from pasture-raised, well-treated, grass-fed cows. Also rest easy knowing the premium protein is free of fillers, added sugars, and artificial sweeteners while being certified gluten-free, vegetarian, and kosher. 

Muscle Feast’s protein comes in two sizes—34 servings and 87 servings—and offers a Subscribe & Save option for 10% off your routine orders. Both options help you get enough protein for your schedule while keeping more dollars in your pocket. 

Overall, Muscle Feast suggests their blend is “best for individuals who want to reap the benefits from having multiple sources of protein included in one powder.” And we also think of this blend sort of like dehydrated cottage cheese (ew?) that’s complete with both casein and whey.

Best Unflavored Casein Protein: NOW Sports Unflavored Casein Protein Powder

Good for: Anyone who’d rather not taste the protein powder 

Best Unflavored

NOW Sports Micellar Casein

GGR Score: 3.6

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Product Highlights

• Micellar casein powder 
• 19 g of protein 
• Non-GMO, kosher, gluten-, nut-, egg-, and soy-free

Pros & Cons

Pros

• Informed Sport–Certified
• No artificial flavors, sweeteners, or preservatives
• Gluten-free

Cons

• Lower protein per serving than competitors
• Only available as unflavored
• Tastes bad according to reviews
• Produced in a facility that processes allergens

Bottom Line

NOW Sports Micellar Casein powder has 19 grams of protein and a short list of ingredients, but the taste is very poorly reviewed.

NOW Sports Unflavored Casein Protein Powder is a great casein-based, tasteless option. It contains 19 grams of protein, which is a touch lower than other proteins, but is based on one 24-gram scoop serving—and is only 90 calories.

GGR performance editor and certified personal trainer Anthony O’Reilly says, “It doesn’t taste like anything, but because of casein’s thicker nature, the shake coats your tongue, which gives it a very slight ‘protein’ taste.” It received a 5 out of 5 for solubility because Anthony says it was much easier to mix in then other casein proteins—and he’s tried nearly a dozen.

Unlike Naked Nutrition, NOW Sport’s casein formula is a two-man casein show joined with sunflower lecithin—which only comprises 1% of the formula—that can help stabilize, preserve, and prevent clumping of the protein. Still, its addition only adds less than 1 gram each of total carbohydrate and fat. 

Beyond the more obvious, NOW’s casein formula meets high industry standards and has an impressive stack of certifications. For starters, it’s packaged in the U.S. by a family-owned and operated company while meeting high-standard GMP (Good Manufacturing Practice) regulations.

The casein protein also sports a “No Artificial Sweeteners” seal to verify no synthetic sweeteners have been added, including aspartame, sucralose, and acesulfame-K. It is also Certified Non-GMO and Kosher, specifically “Triangle K with Dairy” to signify the product is certified kosher but contains dairy.

And to top off the certifications, the NOW casein rocks the Informed-Sport seal, meaning it’s been tested for banned substances by LGC. It also bears the Steroid-Tested logo, a testing system developed by NOW, that focuses on banned substances found in the World Anti-Doping Agency (WADA) banned substance like androgenic anabolic steroids, Selective Androgen Receptor Modulators (SARMs), beta-agonists, estrogen inhibitors, and weight loss drugs.

Best Casein Protein for Baking: Dymatize Elite Casein

Good for: Protein seekers who enjoy appetizing flavors and baking with their protein powder

Best for Baking

Dymatize Elite Casein

GGR Score: 4.2

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Product Highlights

• 100% micellar casein 
• 25 g of protein 
• 5.3 g of BCAAs
• Gluten-free, Informed Choice–Certified, banned substance–free

Pros & Cons

Pros

• Informed Choice–Certified
• Good for baking
• 4 flavor options

Cons

• 2 lb size only available for chocolate and vanilla
• Contains soy
• 1 serving = 2 scoops
• Mixed reviews on taste

Bottom Line

Elite Casein provides 25 grams of protein and is available in four flavors. There are mixed reviews on the taste.

Dymatize Elite Casein is much more than a casein protein powder, although we first need to acknowledge that it provides 25 grams of protein per serving. To enhance protein insight for consumers, Dymatize also itemizes the amino acid profile: 44% (11.2 g) essential amino acids, 31% (7.8 g) conditionally essential amino acids like glutamine, and 25% (6.2 g) non-essential amino acids.

Of course the protein content matters, but the flavor options and utility of Dymatize’s casein powder is something to write home about—or at least share with our readers! With four decadent flavors—including Cinnamon Bun, Cookies & Cream, Rich Chocolate, and Smooth Vanilla—crush cravings by simply mixing the powder with water or milk for a quick protein shake.

Certified sports nutrition coach and former GGR senior fitness writer Amanda Capritto says, “Like other casein protein powders, this one takes some vigorous shaking to rid it of all clumps. To ensure a smooth consistency, I recommend first shaking it, and then using a frother.” She also notes that the Cookies & Cream flavor makes a tasty pudding, although it has a somewhat unappetizing grayish color, which is why it fell short of a perfect 5 and instead received a 4.5 out of 5 on taste.

You could also try baking and add it to countless delicious recipes! If you aren’t sure where to start, Dynamize will keep your culinary game on point with inspiration on their casein product page or blog—protein chocolate covered strawberries, cookies and cream protein pancakes, or edible birthday cake protein cookie dough anyone…? 

BRB, going to grab a (protein-packed) snack… 

In all seriousness, using and adding casein protein powder to “healthified” recipes can keep that sweet tooth tame, hunger at ease, and your health and fitness goals right on track. 

The Dymatize casein blend is Informed-Choice certified, which denotes it’s been tested and monitored by third-party testers and meets international purity standards. The seal also assures consumers that they aren’t subjecting themselves to banned and harmful substances. 

Best Gluten-Free Casein Protein: Ascent Native Fuel Micellar Casein

Good for: People who want peace of mind knowing that their protein powder is certified gluten-free

Best Gluten-Free

Ascent Native Fuel Micellar Casein Powder

GGR Score: 3.2

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Product Highlights

• Micellar casein powder
• 25 g of protein 
• 5 g of BCAAs
• Informed Sport–Certified and 3rd-party tested for banned substances

Pros & Cons

Pros

• Free US shipping on all orders
• 0 artificial ingredients
• Informed Sport–Certified
• Made in the USA
• Taste positively reviewed

Cons

• Limited reviews
• Produced on equipment that also processes tree nuts and peanuts
• Thick texture (common for casein)

Bottom Line

Ascent Protein Micellar Casein Powder has 25 grams of protein per serving and is certified to be banned substance–free. Reviewers loved the taste but many used it as a pudding rather than a drink because of the thickness.

Other casein powders are devoid of gluten, like Muscle Feast and Naked Nutrition, but Ascent Native Fuel Micellar Casein is noticeably gluten-free at first glance at the product page—certified gluten-free, that is. 

Showcasing the certified gluten-free seal means it’s been reviewed by Gluten-Free Certification Organization (GFCO) and meets the strictest of gluten-free standards. Specifically, the product contains 10 or fewer parts per million of gluten and is essential for those managing celiac disease or other gluten-related health conditions.

They’re also Informed-Sport certified, so competitive athletes particularly can feel confident they are consuming a product without banned substances. 

Unfortunately, Nicole Davis, GGR head of content and certified personal trainer, wasn’t a fan of the Chocolate Peanut Butter flavor. In fact, it received our lowest taste score: 2.75 out of 5.

“I really tried to like this because it does have good customer reviews. I mixed it with water, milk, into a shake with frozen banana and ice, and made a pudding. The taste is just very off-putting to me.” She did say the pudding recipe on the bag was the best option and it could make a nice sweet treat for some people—just maybe try the chocolate or vanilla flavors.

And two interesting observations to note: the number of servings also vary based on flavor—Chocolate (about 25 servings), Chocolate Peanut Butter (about 24), and Vanilla Bean (28 servings). The second observation: the price is $44.99 for all flavor options regardless of the servings. You can also snag a 4-pound, 50-serving bag of the chocolate casein powder for $74.99 and save almost $0.20/per serving. 

Aside from any cost and serving confusion, all of the flavor options are free of artificial ingredients. Instead, the brand uses more natural flavors and sweeteners like cocoa and stevia leaf.

Best Grass-Fed Casein Protein: Naked Nutrition Naked Casein Protein

Good for: Consumers who place great emphasis on grass-fed products 

Best Grass-Fed

Naked Nutrition Micellar Casein Protein Powder

GGR Score: 4.4

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Product Highlights

• 100% micellar casein 
• 26 g of protein 
• 5.4 g of BCAAs
• Gluten-free, soy-free, non-GMO 

Pros & Cons

Pros

• 1–3 ingredients (depending on flavor)
• Subscribe and save 20%
• Independent heavy metals and allergen testing
• No additives or artificial ingredients
• 3 flavors, including unflavored

Cons

• Not recommended to use with shaker bottle
• 1 serving = 2 scoops
• Limited reviews

Bottom Line

Naked Casein has 26 grams of protein per serving. It won’t mix well in a shaker bottle, but customers love the short ingredient list.

Naked Nutrition Naked Casein Protein is a high-quality, one-man casein show. That’s right, Naked Nutrition’s casein formula contains only one ingredient and you can very likely guess what that is… 

If you guessed 100% pure micellar casein, you’re 99.99% right. But as our top grass-fed casein pick, of course we have to mention that the micellar casein is specifically growth hormone-free and exclusively sourced from U.S. farms.

The unflavored casein protein powder allows you to get optimal nutrition and customize it to your own tastes. Simply blend any colorful fruit and veggie you enjoy or have on hand—like banana, berries, kale, pineapple, or spinach—and even mix it into the batter of baked goods.

Former GGR senior fitness writer and certified sports nutrition coach Amanda Capritto gave it a 4 out of 5 on taste on its own, but it rose to a 5 when she mixed in cinnamon, nutmeg, vanilla, or a splash of coffee. She also says, “It makes for a fantastic chocolate mug cake!”

The unflavored, 100% pure casein protein powder only provides the macronutrient protein—26 grams of protein per serving, to be exact—with 0 grams of carbs and fat. For those extra interested in the details, you can also peek at the complete amino acid profile on the product label. 

Because the casein protein only contains one ingredient, it goes without saying that it does not contain artificial sweeteners and additives. OK, we had to say it anyway… And it’s also free of soy, gluten, and GMOs. 

All Naked Nutrition products are processed and packaged in GMP-certified facilities, and their casein protein is no exception. They also are certified Informed-Choice Trusted by Sport, so you can have peace of mind knowing that the casein is free of any banned substances.

Best Budget Casein Protein Powder: Optimum Nutrition 100% Gold Standard Casein

Good for: Those who want a quality casein protein without breaking the bank 

Best Budget

Optimum Nutrition Gold Standard 100% Casein

GGR Score: 4

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Product Highlights

• 100% casein
• 24 g of protein per serving 
• 5 g of BCAAs
• 4 flavors available

Pros & Cons

Pros

• 24 g of protein
• Positive customer reviews
• Free shipping on larger container

Cons

• Relatively expensive
• Only 4 flavors
• Contains sucralose

Bottom Line

Optimum Nutrition Gold Standard 100% Casein provides 24 grams of protein and is positively reviewed by users.

Optimum Nutrition is no stranger to GGR and our readers—so much so, we even set out to find the best Optimum Nutrition flavor! Optimum Nutrition Gold Standard 100% Casein’s flavor repertoire might not be nearly as robust as the Optimum Nutrition whey collection, but it still doesn’t disappoint with decadent options like Chocolate Supreme and Cookies & Cream.

Kate Meier, GGR’s senior director of content and a competitive weightlifter, says, “I have used both the Chocolate Peanut Butter and the Chocolate Supreme for protein pudding, and they are both incredibly smooth and delicious. I think the chocolate supreme is almost as good as real chocolate pudding.” Sounds like a 5 out of 5 on taste from us, and many of the customer reviews agree with Kate’s assessment.

While flavor is important (at least we think so), the casein content and quality are mostly what we’re concerned about here—and each scoop serving provides 24 grams of protein sourced by micellar casein. It also provides 9 grams of essential amino acids and nearly 5 grams of branched-chain amino acids (BCAAs) to further support muscle recovery and endurance. 

It’s also rich in other essential nutrients and supplies 100% DV of zinc, 40% DV of calcium, and 20% DV of magnesium. The zinc and magnesium were added, but the calcium is sourced all-nat-u-ral from casein. 

While flavor-dependent, Optimum Nutrition’s casein blends do collectively contain artificial ingredients such as artificial colors and the artificial sweetener sucralose. (With a lower price point, there’s bound to be a compromise somewhere.)

But ingredients aside, you can rest easier knowing that Optimum Nutrition’s products are manufactured in current Good Manufacturing Practices (cGMP) compliant facilities that are also Informed-Sport and Informed-Choice registered. This means the protein meets quality and purity standards while being free of banned substances by athletic organizations. 

The casein protein also comes in 25-serving and 53-serving options, so you can choose what’s best for you depending on your protein needs. But pro tip: stocking up with the 53-serving tub will save you about $0.40 per serving!

Other Casein Protein Powders We Researched

This roundup would be wheyyyy too long if we tried to capture all of the great casein protein powders on the market. While we still stand by our top picks, other products we researched and would recommend include:

• Muscle Milk Sleeping Giant 
• MyProtein Slow-Release Casein
• Nutricost Casein Protein Powder
• Promix Casein Protein Powder

How We Picked and Tested the Best Casein Protein Powder

How we picked and tested the best casein protein powder was meticulous, thorough, and (incidentally) based on the four Fs: the supplement’s formulation, flavor options, financial cost, and faithfulness of the brand. 

Formulation

Analyzing protein, carb, and fat content, plus total calories per serving. This can also include considerations around other ingredients, like branched-chain amino acids (BCAAs), flavoring, or additives.

Ideally, a casein protein powder will mostly contain protein and we strive to find products with at least 20 grams of protein per serving. NOW Sport’s casein—which provides 19 grams of protein per serving—is the exception, although it’s important to note the 24-gram serving size is a bit lower than others. If you calculate the protein based on a typical 30-gram scoop, the NOW Sport’s casein powder would provide about 24 grams of protein.

We also review the purity and quality of the protein—like if it’s sourced from grass-fed cattle—and any additional ingredients. If other ingredients are added, we make sure to rationalize their function and purpose.

Flavor Options

We search for and capture various flavors—and sometimes lack thereof—to satisfy diversified palates, because the best-tasting protein powder will differ for everyone. While some consumers enjoy unique and fun flavors, others prefer non-flavored options that can seamlessly be added to water or hidden with other drinks. 

Financial Cost 

Price per serving can range from $1.25 on the low end to upwards of $2 on the high end.

We firmly believe cost shouldn’t have to dictate reaching health and fitness goals, so you’ll never find a product list of ours without financial flexibility. Many supplement companies also offer the ability to “subscribe and save,” as well as free shipping and additional discounts, so we encourage taking advantage of such options if or as available. 

The Faithfulness of the Brand

Is the brand faithful to its products AND consumers? We pride ourselves on being honest in our reviews and look for similar values in other brands and companies by reviewing: 

• Manufacturing and testing protocols, including if the product is third-party tested
• Access to customer support via chat boxes, phone, contact forms, etc. 
• Return policies and money-back guarantees 
• Brand and product reviews on company websites, seller sites like Amazon, and social media profiles

Benefits of Casein Protein Powder

What the slow-digesting protein can offer has been touched upon. But let’s slow it down and truly capture the benefits of casein protein powder. 

Reinforces Daily Protein Intake

Protein, an essential macronutrient along with carbohydrates and fat, carries out thousands of critical reactions in the body. Supporting hormonal health, body composition goals, and strong immune functions are just a few benefits of protein.

The amount of daily protein you need depends on age, birth sex, health goals, and other factors. Just about anyone could benefit from a protein supplement, despite differing needs from one person to the next, especially if you’re not meeting daily protein targets from wholesome high-protein foods. 

Improves Athletic Performance and Recovery

If you want to improve your performance in the gym, you should be keeping protein in your back pocket. (Not talking literally here, but you do you.) But really, leaning on the best muscle recovery tools and supplements—casein protein included—can, in turn, improve your performance.

A small study conducted in 2013⁵ reiterates that pairing resistance training with pre- and post-exercise protein can induce significant changes in performance and body composition. But when examining performance-enhancing effects between whey and casein proteins, there was not a noticeable difference between the two. 

A first-of-its-kind, yet also small, 2018 study⁶ examined if consuming casein or whey protein could positively improve resting metabolic rate and resistance exercise the following morning. The researchers found that a higher dose of casein protein (48 grams) before sleep may provide small yet favorable changes in morning RMR and performance. 

A more recent 2020 study published in Physical Activity and Nutrition¹ reviewed the effects of pre-sleep casein protein intake on post-workout recovery. The researchers concluded that at least 40 grams of casein after an evening resistance training session, and about 30 minutes before bed, can be an effective strategy to facilitate muscle recovery. 

Assists with Body Composition Goals

Looking to build muscle mass or slim down? Whatever your body composition goal, protein can and should assist. 

Sustaining and growing muscle is essentially the byproduct of resistance training and adequate protein. While casein is digested slowly, thus prolonging amino acid release and use, research⁷ shows that both casein and whey elicit similar increases in muscle protein net balance.

In terms of a protein powder for weight loss, the slow absorption of casein may promote feelings of fullness and control hunger. This ultimately helps to minimize cravings and moderate calorie intake, which may result in weight loss.

Overall, though, much of these body composition benefits are mostly attributed to consuming sufficient protein.

Supports Bone and Dental Health

As a rich source of calcium, it’s not surprising that casein can help support strong bones and teeth. A review in the Journal of the American College of Nutrition⁸ suggests that casein supplementation reduces post-fracture bone loss, medical complications, and hospital stays while increasing muscle strength.

Research published in Caries Research⁹ even hints that casein and casein-derived proteins reduce or prevent enamel erosion, especially when paired with fluoride. Additional research out of the Australian Dental Journal¹⁰ proposes that casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)—produced from milk protein casein with a great ability to stabilize calcium phosphate—could be a natural addition to chewing gums and food products to lower the risk of dental caries. 

(Perhaps there’s double dental support if you drink a pre-sleep casein protein shake and then brush your teeth!?)

Honors Convenience and Versatility 

Whether you’re on the go or just looking for a convenient option, protein powders are shelf-stable and easily transported without the worry of keeping cold or going rancid. Plus, there’s less worry about food waste when compared to letting that package of chicken breasts expire!

Protein powders are also highly versatile—simply mix with water or another liquid for a quick protein shake, blend into smoothies, bake into countless recipes, and so much more. Really, protein powders can be as convenient and versatile as you wish them to be! 

Dosing and Interactions 

So now that you’re close to picking a casein protein powder right for you (more detailed guidance up next!), how much protein should you consume? Does casein protein increase the risk of any interactions? Let’s explore protein dosing and potential interactions to give you better peace of mind. 

Protein Dosing

Again, the amount of protein you should consume each day depends on many factors like age, birth sex, and activity levels. As a general starting point, use protein’s Dietary Reference Intake (DRI) of 0.80 grams of protein per kilogram (g/kg) or 0.36 grams of protein per pound (g/lb) of body weight. For someone who weighs 200 pounds (90.9kg), this amounts to 72 grams of protein per day. 

However, DRIs denote the lowest daily intake value for a nutrient and research¹¹ recommends consuming at least 1.2 to 1.6 g/kg of high-quality protein for optimal health. Based on the same 200-pound individual, this would equate to 109 to 145 grams of protein per day.

RELATED: Best Organic Protein Powder

Factoring in body composition and performance goals can vary protein targets. If your goal is weight loss, and you are in a caloric deficit, up to 2.0 g/kg may protect you from losing precious lean muscle. Aiming for 1.2 to 2.0 g/kg each day shows to support athletic performance and recovery according to 2019 data published in Nutrients.¹²

Certain health conditions can also influence protein needs. For instance, people managing liver or kidney diseases¹³ may need to limit their protein intake. 

Casein Interactions and Safety

While there are currently no noted casein protein interactions at this time, casein peptides might decrease blood pressure and cause blood pressure to drop even more if taking an anti-hypertensive medication. People with a milk allergy can be allergic to casein, which is a milk protein, and would benefit more from a non-dairy option like a vegan protein powder. 

Milk allergies should also not be confused with lactose intolerance, in which the body doesn’t make enough of the enzyme lactase to break down the milk sugar lactose. Casein might be a viable option for those with lactose intolerance, as most, if not all, of the lactose is removed, although it’s still wise to consume with caution. 

If you have any questions and/or concerns about all things protein dosing and interactions, we encourage consulting with a registered dietitian for expert guidance. 

Buying Guide: What to Look for in Casein Protein Powder

Ready to experience the benefits of a casein protein supplement yourself? Review the following tips and steps before punching in your credit card number.

Formulation

All of our top picks follow this simple principle: the majority, if not all, of the formulas should contain protein with next to no fillers and fluff. Especially if choosing a casein protein powder beyond our list, be sure to review the following:

• Protein content and type: Choose a casein protein powder that supplies at least 20 grams of protein per serving. Also opt for micellar casein, which is in most casein protein powders. 

• Carbohydrates and fat content: While carbs and fats are essential macronutrients like protein, they aren’t exactly necessary in a protein powder. But if you’re looking to use a protein supplement as a meal replacement, we recommend using a specifically formulated meal replacement powder or pairing it with carbs and fats for a more satiating and balanced meal.
• Additional ingredients: Again, a protein powder should mostly contain protein with little to no carbs and fats. If the casein protein contains anything more than micellar casein, we advocate for choosing products with intentional ingredients—like stevia to enhance the sweetness and flavor—over ones with added sugars, fillers, and other unnecessary ingredients.

RELATED: Best BCAA for Women

Personal Needs and Budget

Absolutely are we not trying to deter you from supplementing with casein. But because you’ll be spending about $50 per container give or take, it’s smart to consider if you actually NEED one and how it could benefit your current lifestyle. If you’re searching for a convenient protein source or wanting to fine-tune your recovery, casein is a great option. 

Also considering protein powder is non-perishable, unlike the casein from cottage cheese, it can be a cost-effective investment to hit your daily protein targets. However, you should still factor in how much you’re willing to pay for protein powder (or any supplement for that matter).

Most casein protein powders provide at least 15 servings per container—but more often around 30 servings—although some brands offer larger sizes. If you can, we recommend opting for the largest size available so that you’ll be stocked and ready—and very likely save some dollars you can put toward another tub or product! 

You can also snag free shipping and/or a “subscribe and save” option with most protein powders. We do recommend trialing the protein before committing to a recurring protein shipment, or at least remembering to skip or cancel orders if you’re still only a few scoops deep.

Flavor (or Non-Flavor) Preference

Some casein protein powders—like Naked Nutrition’s and NOW Sport’s products—are unflavored. This allows you to add them to water, smoothies, and other recipes without much notice. 

But if you have a sweet tooth or simply prefer tasty options, there are many satisfying flavors on the market. Also because what qualifies as the best tasting is personal, go for a flavor you think you’ll enjoy the most so you can hit your protein targets with delight. 

Certifications and Verifications

Because supplements are not tightly regulated, it’s smart to review any certifications and verifications they hold. All might not be important to you—like being Certified USDA Organic or Certified Gluten-Free—but we do recommend double-checking if the product is manufactured in NSF-certified, FDA-inspected, and/or cGMP-compliant facilities and third-party tested.

Company Values and Integrity

We’re always evaluating the company behind the product and encourage you to do the same as a consumer, especially if supporting them with your purchase. While everyone has their own unique set of values, key areas we look into include:

• An “About Us” page, or one that’s similar, that details the company’s mission and core values—do their values align with yours?
• Consumer reviews on the company’s main website, social media profiles, and third-party seller sites as available.
• Return policies and money-back guarantees, which help reassure us the company feels confident in its product while prioritizing consumer satisfaction.

So before confirming your purchase, we encourage you to make a few more clicks, poke around their websites, and explore their social profiles—and maybe check us out while you’re there! 

FAQs About Casein Protein Powder

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any diseases.

References

1. Kim J. Pre-sleep casein protein ingestion: new paradigm in post-exercise recovery nutrition. Phys Act Nutr. 2020 Jun 30;24(2):6-10. doi: 10.20463/pan.2020.0009. PMID: 32698256; PMCID: PMC7451833.
2. Koopman R, Crombach N, Gijsen AP, et al. Ingestion of a protein hydrolysate is accompanied by an accelerated in vivo digestion and absorption rate when compared with its intact protein. Am J Clin Nutr. 2009 Jul;90(1):106-15. doi: 10.3945/ajcn.2009.27474. Epub 2009 May 27. PMID: 19474134.
3. Lollo PCB, Silva LBC, Batista TM, et al. Effects of whey protein and casein plus leucine on diaphragm the mTOR pathway of sedentary, trained rats. Food Res Int. 2012;49(1):416-424. doi:https://doi.org/10.1016/j.foodres.2012.07.024
4. Soop M, Nehra V, Henderson GC, et al. Coingestion of whey protein and casein in a mixed meal: demonstration of a more sustained anabolic effect of casein. Am J Physiol Endocrinol Metab. 2012 Jul 1;303(1):E152-62. doi: 10.1152/ajpendo.00106.2012. Epub 2012 May 8. PMID: 22569072; PMCID: PMC3404559.
5. Wilborn CD, Taylor LW, Outlaw J, et al. The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes. J Sports Sci Med. 2013;12(1):74-79. Published 2013 Mar 1.
6. Madzima TA, Melanson JT, Black JR, et al. Pre-Sleep Consumption of Casein and Whey Protein: Effects on Morning Metabolism and Resistance Exercise Performance in Active Women. Nutrients. 2018 Sep 10;10(9):1273. doi: 10.3390/nu10091273. PMID: 30201853; PMCID: PMC6164527.
7. Tipton KD, Elliott TA, Cree MG, et al. Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise. Med Sci Sports Exerc. 2004 Dec;36(12):2073-81. doi: 10.1249/01.mss.0000147582.99810.c5. PMID: 15570142.
8. Bonjour JP. Dietary protein: an essential nutrient for bone health. J Am Coll Nutr. 2005 Dec;24(6 Suppl):526S-36S. doi: 10.1080/07315724.2005.10719501. PMID: 16373952.
9. White AJ, Gracia LH, Barbour ME. Inhibition of dental erosion by casein and casein-derived proteins. Caries Res. 2011;45(1):13-20. doi: 10.1159/000322300. Epub 2010 Dec 11. PMID: 21160185.
10. Philip N, Walsh L. The potential ecological effects of casein phosphopeptide-amorphous calcium phosphate in dental caries prevention. Aust Dent J. 2018;64(1):66-71. doi:https://doi.org/10.1111/adj.12661
11. Phillips SM, Chevalier S, Leidy HJ. Protein “requirements” beyond the RDA: implications for optimizing health. Appl Physiol Nutr Metab. 2016 May;41(5):565-72. doi: 10.1139/apnm-2015-0550. Epub 2016 Feb 9. Erratum in: Appl Physiol Nutr Metab. 2022 May;47(5):615. PMID: 26960445.
12. Carbone JW, Pasiakos SM. Dietary Protein and Muscle Mass: Translating Science to Application and Health Benefit. Nutrients. 2019;11(5):1136. Published 2019 May 22. doi:10.3390/nu11051136
13. Shi J, Wang Y, Wang S, et al. Use of low-protein staple foods in the dietary management of patients with stage 3-4 chronic kidney disease: a prospective case-crossover study. BMC Nephrol. 2022;23(1):114. Published 2022 Mar 21. doi:10.1186/s12882-022-02734-6

Sydney Lappe, R.D.

Sydney Lappe is a St. Louis-based Registered Dietitian with 6+ years of nutrition editing and writing experience. She holds a Master’s Degree in Nutrition and Dietetics and completed undergrad work in psychology. While fitness wasn’t in Sydney’s routine growing up, it quickly became a large part of her daily life while studying the facets of health and nutrition. Also managing chronic pain, she has come to fully realize movement is a special gift to never take for granted and hopes to inspire others to invest in their physical, mental, and emotional wellness while they can. Including her passion for all things health, Sydney enjoys spending time with her loved ones, being active in various capacities, drinking bottomless cups of coffee, eating a hearty bowl of oatmeal, and letting her creativity roam through writing and graphic design.

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Adequate rest and protein intake are the pillars of muscle growth, especially when applying progressive overload on a regular basis. This might make casein protein powder—often called the “sleep protein”—the ultimate synergist for taking your fitness goals to the next level. That’s because casein digests slower than whey protein, so it keeps you fuller for longer—such as when you’re asleep.Don’t just take our word for it! A 2020 systematic review published in Physical Activity and Nutrition1 suggests that pre-sleep casein intake might facilitate muscle recovery after a bout of resistance exercise.  » Read more about: The 8 Best Casein Protein Powders (2024): High-Quality Options Reviewed by a Registered Dietitian  » Read more