The 4 Best Casein Protein Powders: Dietitian Approved

We collaborated with a certified nutrition coach and product testers to evaluate and select the four best casein protein powders to support your muscle growth and recovery in preparation for 2026!

Best Casein Protein Powder of 2025

• Best Casein Protein Powder Overall: Transparent Labs Casein Protein
• Best Tasting Casein Protein Powder: Legion Casein+
• Best Budget Casein Protein Powder: Muscle Feast Micellar Casein Protein
• Best Casein Protein Powder for Muscle Gain: Optimum Nutrition Casein

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Our team of expert testers has tried hundreds of the most popular supplements on the market today, using our comprehensive supplement testing methodology.

Best Casein Protein Comparison Table

Best Casein Protein Powder Overall: Transparent Labs Casein Protein

Our Thoughts on Transparent Labs Casein Protein

Transparent Labs Casein Protein powder is our pick for the best casein protein overall because it’s made from 100% grass-fed micellar casein, is third-party tested for purity, and it avoids artificial sweeteners and fillers. With 25 grams of protein per serving, it’s ideal for athletes and health-conscious folks wanting reliable, slow-release protein to fuel muscle growth and keep hunger in check between meals.

Our tester Pete, a certified nutrition coach, tried this casein protein, rating it a 4 out of 5 for his first impression. “It comes in a very large white tub that would take up a significant amount of space in a kitchen cabinet,” he said. “The logo is aesthetically pleasing, easy to read, and provides the relevant information a consumer would be looking for on the label.”

After shaking up the product in a standard shaker bottle, he was pleased with how well it dissolved. He rated the mixability a 5 out of 5: “Casein always has a grainier texture than whey protein powder,” Pete mentioned. “Despite mixing fully, it tastes slightly grainy. There were no visible chunks.” He recommends drinking the casein quickly after mixing, otherwise, it settles on the bottle of the container and develops a thick foam on the top. If this happens, it’s best to add more liquid and re-shake. While our team would usually dock a protein for settling, casein is a bit different than your standard whey—settling is common unless you use a blender.

“It has a subtle chocolate flavor, very similar to cocoa powder, which makes sense since that’s what they use in the ingredients list. It’s also not very sweet and doesn’t leave you with a stevia aftertaste. It feels slightly grainy,” he said, giving the flavor a 3 out of 5. While we think this product could have used a little more sweetness, we were impressed with the clean, simple formula.

Best Tasting Casein Protein Powder: Legion Casein+

Our Thoughts on Legion Casein+

Legion Casein+ is our pick for best-tasting casein protein powder, thanks to its rich flavors, clean profile, and impressive protein density. Whether you prefer your shake thick and satisfying, or want to craft a decadent protein pudding, Legion has versatile options like cinnamon cereal or Dutch chocolate; all flavors are free from artificial sweeteners or fillers. 

Pete tested Legion’s Casein+ and rated it a 5 out of 5 for his first impression. As opposed to most powder supplements, which come in a tub, this one is available in a resealable plastic bag. This container style takes up less space and still includes a scoop. 

Once Pete shook up a scoop in his shaker cup, he was impressed with the mixability, rating it a 5 out of 5. “The casein protein fully dissolved in 60 seconds. There weren’t any visible chunks or clumping, and the texture was surprisingly smooth for a casein protein. There wasn’t a grainy texture that’s very common with casein protein supplements,” he said.

Our tester loved the flavors of Legion’s Casein+, giving it a glowing 4.5 out of 5 rating. “This is honestly one of the best tasting casein protein powders I have tried,” Pete said. “The texture was great; it didn’t have that grainy or gritty consistency that’s common with casein protein powders. I tried the cinnamon cereal flavor and it was delicious, very reminiscent of the milk in your cereal bowl after some Cinnamon Toast Crunch.”

Best Budget Casein Protein Powder: Muscle Feast Micellar Casein Protein

Our Thoughts on Muscle Feast Micellar Casein Protein

Muscle Feast Micellar Casein Protein is pick for the best budget-friendly casein because it combines quality with affordability. Sourced from grass-fed cows and free of artificial ingredients, it offers a straightforward, high-protein option that fits a wider range of dietary needs. The transparent ingredient list and third-party testing add a layer of trust you don’t always get at this price point, making it an excellent pick for anyone seeking dependable and affordable casein.

Pete tested this casein protein, rating it a 5 out of 5 for his first impression. As with Legion, he liked that this product came in a resealable bag with a scoop included. The label was easy to read and clear, though Pete did note that it’s likely not travel-friendly.  

“The supplement fully dissolved in 60 seconds using a standard shaker bottle,” Pete said, rating its mixability a 5 out of 5. This formula dissolved well in only a shaker cup and didn’t require a blender to fully dissolve.

After trying a scoop, Pete’s experience with the flavor was fairly good, and he rated it a 3 out of 5 for taste. “I tested the chocolate flavor, it had a natural flavor profile and you could taste the cocoa powder. It had a solid balance of flavor and sweetness and overall was a good tasting shake,” Pete said. He noticed a slightly grainy consistency, which is very common with casein protein powders.

Overall, Pete thinks this is a high-quality casein protein. He likes that it’s free of artificial ingredients, uses minimal ingredients, and provides 27 grams of casein protein per serving at only 110 calories—this is a very high protein-to-calorie ratio.

Best Casein Protein for Muscle Gain: Optimum Nutrition Casein

Our Thoughts on Optimum Nutrition Casein

Optimum Nutrition Casein is our top pick for the best casein protein for muscle gain because it includes pure, slow-digesting micellar casein protein, trusted by athletes and backed by a long-standing brand reputation for quality and results. The formula’s 24 grams of protein per serving helps with muscle repair and growth overnight, while the blend’s creamy texture and digestibility work well in everything from simple shakes to casein puddings.

Pete tested Optimum Nutrition’s casein protein, rating it a 5 out of 5 for his first impression. “It comes in a black plastic container with a screw top lid that’s easy to open and close. They provide a scoop,” he said. Though it’s definitely too large to be suitable for travel. 

The casein protein dissolved in 60 seconds, and Pete said there were no visible chunks of powder or clumping. There was a slightly grainy consistency, but overall it mixed very well for a casein protein, and he rated mixability a 5 out of 5.

“I’m normally not a huge vanilla fan, but the creamy vanilla flavor was very good,” Pete said. “It had a strong vanilla flavor and a nice balance of sweetness.” He rated the taste a 5 out of 5, and the sweetness a middle range 3 out of 5. “The mouth feel did have a slightly grainy consistency, but overall it was smooth for a casein protein powder. The shake felt light and was easy to drink,” Pete said.

What is Casein Protein?

Casein protein is a slow-digesting, high-quality dairy protein naturally found in milk and commonly used as a supplement for muscle repair and sustained nourishment. Unlike other proteins, casein forms a gel-like substance in the stomach, releasing amino acids gradually, which helps to feed muscles over a longer period—making it a popular choice for nighttime use or long fasting intervals.

What makes casein unique is both its satiety-boosting effects and its ability to help protect muscle tissue from breakdown, especially between meals or during sleep. Its slow absorption sets it apart from faster proteins like whey, offering a steady protein supply for several hours.

Casein Protein vs. Whey Protein

While both casein and whey come from milk, they differ significantly in how the body digests and uses them. Whey is absorbed quickly, spiking blood amino acid levels and making it excellent for post-workout muscle repair. In contrast, casein digests slowly due to its gel-forming properties, providing a prolonged release of amino acids to support muscle maintenance and help curb hunger. 

• Whey is ideal for those who want rapid protein absorption after exercise to ignite muscle growth, thanks to its higher content of muscle-building BCAAs. 
• Casein suits people seeking overnight recovery, appetite control, or who want to prevent muscle breakdown during longer periods without eating. Some athletes use both, timing whey for after workouts and casein before bed for 24-hour muscle support.

How We Tested and Selected the Best Casein Protein Powders

To ensure every pick is safe and effective, our team collaborated closely with a certified nutrition coach throughout the evaluation process. Here’s a bit more about our process and selection.

Formula

Each casein protein was analyzed for clinically backed dosages or ingredients that fit the recommended daily values, with a preference for formulas that provide real benefits for muscle support. We also prioritized products without unnecessary artificial sweeteners, colors, or additives, focusing on those that use simple, recognizable ingredients to promote clean nutrition and minimize the risk of negative side effects.

Taste and Texture

We believe that flavor is a major factor in long-term supplement use. For each casein protein, we conducted blind taste tests when possible to avoid bias and get an authentic feel for the flavor and mouthfeel. Our team also took close of the sweetness, opting for products that weren’t too sweet and left little to no artificial aftertaste. Our tester also paid close attention to how the protein mixed—whether it was creamy, smooth, or if there were any unwanted aftertastes or artificial notes. 

Mixability 

Each casein protein was mixed exactly as instructed by the manufacturer, whether with water, milk, or a milk alternative. We paid attention to how easily the powder dissolved and sought to avoid gritty, clumpy, or chalky textures. Good mixability means less hassle and a more enjoyable drinking experience, so we prioritized casein proteins that delivered smooth, lump-free consistency with minimal effort.

Third-Party Testing

With supplements, safety and trust are vital. That’s why we placed strong emphasis on casein proteins that are third-party tested—a process where an independent lab verifies the purity and label accuracy of the supplement before it hits the market. Since supplements aren’t regulated by the FDA in the same way as food or medicine, third-party testing provides extra assurance that a product really contains what it claims, without unsafe contaminants or misleading ingredient lists.

Value

Finally, we weighed each factor above against the casein protein’s cost per serving to identify the best value overall. We looked for the right balance between ingredient quality, taste, efficacy, and price, spotlighting products that offer the most benefits for your investment.

How to Find the Best Casein Protein for You

Navigating the world of casein protein can feel overwhelming with all the brands, flavors, and claims. Here’s how to sift through the choices and pick the one that fits your lifestyle and fitness goals.

Your Fitness Goals

Different athletes and individuals have unique objectives, which can help shape the perfect casein pick. If you’re focused on building muscle, choose a formula with a higher protein content per serving. Folks looking for weight management might prioritize casein’s impressive satiety benefits, which can help curb hunger between meals. Endurance athletes and late-night snackers may value slow-digesting casein for overnight muscle recovery and all-day nourishment.

Flavors

If you’re planning to drink your casein protein powder daily, finding a flavor you genuinely enjoy is essential. Look for a product with positive reviews for taste or start with a smaller tub to sample before committing to a larger size. Enjoying the flavor ensures you’ll stick with it, whether you’re sipping it straight or mixing it into a recipe.

Formula

Each person has unique dietary requirements, so review the casein protein’s formula carefully before purchasing. Some formulas are higher in protein; others include added digestive enzymes, vitamins, or minerals, and some are made for specific dietary needs like gluten-free or non-GMO. Consider the full macronutrient breakdown—protein, carbs, fats—and make sure it fits your health goals and any recommended daily values (RDVs). Clean ingredient lists with minimal artificial additives are ideal for most users.

Cost

Supplements, especially cleaner formulas, can be expensive. It’s important to factor the price per serving into your decision—higher prices often reflect higher-quality ingredients and better manufacturing practices. 

Third-Party Testing

When selecting any supplement, third-party testing should be near the top of your checklist. This means an independent laboratory has verified the product’s quality and ingredient claims, adding a level of safety and transparency that the FDA doesn’t require for supplements the way it does for food and drugs. Prioritizing third-party tested proteins helps ensure you’re getting exactly what’s listed without harmful contaminants, undisclosed fillers, or inaccurate ingredient lists.

Benefits of Casein Protein Powder

Adding casein protein powder to your routine offers a number of unique benefits. Here are a few:

• Digests slowly, which may be more helpful for some folks than whey
• Supports overnight muscle recovery, feeding your muscles a steady stream of amino acids while you sleep 
• Helps prevent muscle breakdown during fasting or long periods between meals 
• Promotes satiety, keeping you feeling fuller for longer and reducing unnecessary snacking 
• Can aid in fat loss while preserving lean muscle, especially during calorie-restricted diets

How to Take Casein Protein

Casein protein works well as a shake—just mix with water, milk, or your favorite milk alternative and blend or shake thoroughly. But don’t stop there: its thick texture makes it a great option to stir into yogurt or blend into smoothies for a creamy boost. Many people enjoy making casein protein “pudding” by mixing the powder with a small amount of liquid until smooth; it can also be used in baking protein-rich pancakes, muffins, or bars for a tasty snack, too.

When to Take Casein?

The best time for casein is typically before bed, as its slow release keeps muscles nourished throughout the night, supporting muscle repair and growth. It’s also a solid choice between meals or as a late-night snack to stave off hunger, though you could also try a meal replacement shake.

Frequently asked questions

Which casein protein is the best?

Transparent Labs Casein Protein powder is our pick for the best casein protein overall because it’s made from 100% grass-fed micellar casein, is third-party tested for purity, and it avoids artificial sweeteners and fillers. With 25 grams of protein per serving, it’s ideal for athletes and health-conscious folks wanting reliable, slow-release protein to fuel muscle growth and keep hunger in check between meals.

Does casein affect testosterone?

There is no strong evidence that casein protein negatively affects testosterone levels when used as directed in healthy adults. Like all supplements, it should be part of a balanced diet and not exceed recommended dosages.

Is it better to take whey or casein?

Whey protein is rapidly absorbed and best immediately after exercise for quick muscle recovery, while casein digests slowly, making it ideal for overnight recovery or extended periods without food. Many athletes use both: whey for post-workout, casein for nighttime.