8 best casein protein powders 2024, expert reviewed | Fortune Recommends

Nov 05, 2024

By Meghan Novoshielski, MS, RDN

Expert Contributor Chris Mohr, PhD, RD

Reviewed by Joana Neziri, MS, NASM-CPT

Fact Checked by Kelly Uhler

Using the expertise of registered dietitians, our team scrutinized product ingredients, brand integrity, safety practices, value, taste, and customer experience to ensure we brought you options you can count on to help you achieve your health goals.

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Chris Mohr, Ph.D., RD, a renowned sports nutritionist, provided his insight to help ensure this story’s medical accuracy. Lily Moe and Joana Neziri, two seasoned nutrition editors, also reviewed the story. Lastly, Kelly Uhler provided fact-checking.

Casein protein is derived from milk, like whey, and is a complete protein known for its slow digestion, which takes several hours to absorb fully. This slow digestion rate may help support muscle growth during long periods without food, like overnight, and it may help manage hunger during weight loss. ( 1 ) Additionally, many casein-rich foods are high in calcium, supporting bone health. ( 2 )

Most dairy foods will give you a healthy dose of this protein, with dairy milk, for example, providing about 80% casein and 20% whey. Casein protein powders can also be a convenient way to maximize your intake within a specific diet plan. So which one is best to get you to your goals? Our team of dietitians and fitness experts did a deep dive into some of the best protein powders . We evaluated ingredient quality, safety, value, taste, customer satisfaction, and more. Using these insights, we compiled the following list of best casein protein powders to help you decide what might work best for you.

Legion Casein+ stands out as our editor’s choice due to its well-rounded nutritional profile and high-quality sourcing. Here’s why we think it’s a top pick:

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.

When choosing a casein protein powder, focus on more than just total protein content. Check the calories, sugar, fat, and carbohydrate content to ensure the slow-digesting formula fits into your daily nutrition goals, especially if you’re using it as a nighttime supplement.

Opt for casein products that fully disclose their ingredients. Look for minimal additives, and avoid those with unnecessary fillers or artificial components that might cause digestive issues or reactions.

Ensure your casein protein is third-party tested for potency and purity. This is the only way to know for sure that what is on the label is what you’re getting, and nothing else.

Make sure you pick a flavor you enjoy and a product that fits your budget for long-term use. Consistency is key to reaping the benefits of this slow-releasing protein.

Legion Casein+ provides a well-rounded nutrition profile in a clean-label formula. Four flavors are available, helping to add variety to your supplement routine. Plus, third-party testing is conducted to provide peace of mind that you’re getting quality ingredients.

Legion Casein+ stands out as the best natural casein protein powder due to its clean, well-rounded formulation that supports optimal protein intake. Each scoop provides 24-26 grams of micellar casein protein and 50-60% of your daily calcium needs with no added sugars, two to five grams of carbohydrates, and 110-140 calories, depending on which flavor you choose. Its low carbohydrate content, ranging from two to five grams per serving, makes it an excellent choice for those mindful of their macros.

Experts often prefer micellar casein since it maintains the natural structure of casein protein, which coagulates in the stomach and slows digestion. Other forms of casein, like casein hydrolysates, are processed into smaller molecules, losing some slow-digesting benefits. While micellar casein is more popular, there’s no clear proof that one type is better than the other. ( 3 , 4 )

“Casein has always been marketed as the slower digesting protein that fitness enthusiasts could benefit from consuming overnight or other times they may have a long time without food. While this benefit was heavily marketed many years ago, it’s interesting to see that research has caught up and data are suggesting at least 40 grams of casein protein, post-exercise and around 30 minutes before sleeping can help sustain muscle during the overnight fast.” ( 1 )

Chris Mohr, PhD, RD, Fortune Recommends Advisor

Although Legion’s nutrition profile is comparable to that of the other products on our list, it stands out for a few reasons. First, it uses only naturally derived flavors, sweeteners, and food coloring. It’s also soy-free, gluten-free, and non-GMO project verified, meeting many people’s dietary needs.

Legion goes the extra mile to pursue best practices in sourcing. Their casein is sourced from Truly Grass Fed ®, a brand of Irish dairy products committed to sustainability and animal welfare. According to their website, they guarantee that their cows live on pasture and eat grass 95% of the year. None of their products contain hormones or antibiotics.

Finally, for safety and integrity, Legion sends its products for third-party testing to check for ingredient potency and harmful contaminants. They also avoid making sensational claims on their website, providing realistic information about what this product can help with. Best of all, they stand behind their products with a 100%, no-questions-asked money-back guarantee. They don’t even require you to send the product back to them, so there’s very little risk in trying it.

Related: The best clean protein powders

Legion Casein+ has a few downsides to consider. At $2 per serving, it costs more than most of the other brands on our list. The good news is that their subscription program discounts their products to $1.80 per serving, which is more in line with the average cost of casein protein powder.

You should also be aware that Legion products contain stevia as well as sugar alcohol, which can cause digestive symptoms in some people. ( 5 )

Also, our testers noted that Legion Casein+ works best when mixed with milk rather than water. When mixed with water, it leaves an unappealing chalky taste that will coat the inside of your mouth. Also, if it sits too long, the mixture will start to separate.

1,094 reviewers on Amazon have rated Legion Casein+, and overall, customers are happy with the taste and quality of the casein powder.

“It’s tasty, has a really nice smooth and creamy texture, mixes well, and has a great protein for calories ratio. On the pricier side, but I find this to be of an excellent quality, and it justifies the price for me.”

Alicia H., Amazon

Jeff D adds, “What I really like is that the marketing does match what their products are. They don’t have as many random ingredients with questionable data behind them and are more simple. Some people look at that as a negative, but I would rather use quality products that are intentionally designed than the kitchen sink ones.”

Among the few complaints, customers recommend handling the product carefully, as the fine powder can easily make a mess. And, if you don’t like stevia, you won’t like this product.

“This may not apply to anyone else, but I, personally, can’t handle Stevia as a sweetener,” James writes. “To me, it tastes just like aspartame—a very chemical-like aftertaste. I’m sure this is just a matter of taste (or perhaps how I’ve trained my taste buds), but I wasn’t a huge fan of this stuff in the amount necessary to make a shake. Just too much Stevia flavor for me.”

Transparent Labs provides 25 grams of 100% grass-fed micellar protein for just 120 calories per serving. With rich chocolate flavor and a healthy dose of calcium , Transparent Labs is an excellent choice, but you’ll want to be aware it contains a fair amount of sodium at 300 milligrams per serving.

Transparent Labs is known for creating quality supplements with straightforward formulations, and their casein protein powder is no exception. Transparent Lab’s casein gets extra recognition for its great taste. The only available flavor is chocolate, but our testers raved about it. They love its rich chocolate taste with a subtle hint of saltiness from the Himalayan rock salt.

A popular recommendation is to use this powder to make chocolate pudding. To do so, simply add less water than instructed. One tester compared it to a classic Jell-O pudding cup, highlighting its smooth texture and authentic chocolate flavor.

Beyond its flavoring, it offers many other perks. One-scoop serving delivers a substantial 25 grams of 100% grass-fed micellar casein and 60% of the daily value of calcium with no added sugars, only four grams of carbohydrates, and 120 calories.

This casein protein powder’s simple ingredient list is free of soy, gluten, artificial sweeteners, and dyes. Plus, sourcing from grass-fed cows may help boost this product’s nutrient content while limiting exposure to hormones and antibiotics, according to some data. ( 6 ) Additionally, this supplement is Informed Choice Certified, meaning a third party tests it for harmful and banned substances.

With Transparent Labs 100% Grass Fed Casein, it’s worth noting that this product has the highest sodium content on our list, with 300 milligrams per scoop, slightly over 10% of the daily value. Note that it does use stevia, which some customers may wish to avoid.

At $2 per serving, Transparent Labs 100% Grass Fed Casein is our list’s second most expensive product. However, if you crave a chocolate treat, it just may be worth it.

Nutricost offers 24 grams of micellar casein at about half the cost of comparable products, making it a more affordable option for those needing multiple servings to meet higher protein targets for muscle gains.

Nutricost provides 24 grams of micellar protein in each serving for about half the cost of comparable products. This affordability is a plus for people trying to build muscle mass who may need more than one serving daily to meet their protein goals.

Research suggests that to gain muscle strength, you need about double the recommended daily allowance (RDA) for protein intake, approximately 1.6 grams per kilogram of body weight. ( 7 , 8 ) To maintain these gains, casein is often recommended as a bedtime supplement because its slow digestion can help support muscle growth and recovery overnight. However, these benefits are only seen with doses of at least 40 grams taken post-exercise and about 30 minutes before sleep. ( 1 ) Nutricost can help you hit these high-protein targets without breaking the bank.

Nutricost’s vanilla casein is also versatile. It works well in chocolate peanut butter protein waffles and high-protein cookie dough, meaning you don’t have to drink multiple protein shakes to hit your protein targets. (You can find these recipes and more on Nutricost’s website.) Plus, its lean nutrition profile allows you to create recipes that are dialed in to your specific nutrient parameters. One serving contains just 110 calories, one gram of carbohydrates, 190 milligrams of sodium, and 45% of the daily value of calcium.

Another perk Nutricost offers is convenience. The Nutricost casein comes in a five-pound tub with 71 servings. If you take two servings a day, this will last you well over a month.

Related: The best low-carb protein powders

It’s worth noting that this product does contains artificial flavors and sucralose, which some people may wish to avoid. On the bright side, it’s third-party tested, so you can rest easy knowing it’s monitored for harmful substances like heavy metals and contaminants.

To learn more, check out our full Nutricost protein powder review or our complete guide on the best protein powders for muscle gain .

Nutricost Vanilla Casein has garnered over 1,800 customer reviews on Amazon. Most appreciate its versatility and affordability and think the flavor is decent.

“This is really good stuff. High quality, low calorie, pretty good flavor. It mixes well with almond milk and frozen fruit for a smoothie to curb cravings.”

Andrew, Verified Amazon Buyer

Another customer, Tom F., describes it as a “good product” at a “great value.”

However, other reviewers think it’s just okay due to the gritty texture. Nathan S. writes, “It’s not the best tasting, but it’s great for long-digesting protein.”

Promix unflavored casein provides 25 grams of grass-fed micellar casein per serving with no artificial additives , chemical aftertaste, or non-calorie sweetness. Its simple formula delivers excellent nutrition, while its versatility and convenience make it an ideal choice for various uses.

Promix offers a great unflavored casein protein powder because of its minimal ingredients, versatility, and affordability. Each two-scoop serving provides 25 grams of grass-fed micellar casein with no artificial sweeteners or additives, making it a good fit for people seeking a simple and versatile casein protein powder.

With Promix’s unflavored casein protein powder, you can create recipes with flavors you enjoy instead of being stuck with chalky, artificially sweetened protein powder. Our favorite ways to use unflavored casein powder include adding it to pancake batter, mixing it into oatmeal with cinnamon, or blending it with vanilla almond milk, bananas, and ice. Promix’s formula reportedly works well with these types of recipes, adding a creamy texture without an artificial aftertaste.

Still, a major advantage of Promix’s unflavored casein is its straightforward formula, containing only two ingredients: micellar casein and sunflower lecithin. This simplicity results in an impressive nutritional profile with just 105 calories, 45 milligrams of sodium (the lowest on our list), no sugar, and 63% of the daily value of calcium per serving.

Promix’s pared-down formula also keeps it affordable; at $1.14 per serving, it’s one of the best values available. Additionally, it comes in a five-pound package that lasts over two months, offering extra convenience and cost savings.

Despite its reasonable price, the company commits to ensuring ingredient quality. This casein is ultra-filtered to remove lactose for easy digestion, and each batch undergoes third-party testing.

Upon testing, we learned Promix doesn’t dissolve well in plain milk or water. Instead, it leaves a gritty texture and an unpleasant aftertaste. The same issue occurs when mixed with plain liquid in a shaker bottle.

Upon testing, we learned Promix doesn’t dissolve well in plain milk or water. Instead, it leaves a gritty texture and an unpleasant aftertaste. The same issue occurs when mixed with plain liquid in a shaker bottle.

Promix Casein has received 610 customer reviews on Amazon. Customers praise this product for its quality and simplicity.

“It’s what the casein does NOT have that should get your attention!” After searching for a quality protein powder without additives or sweeteners for a while, she feels “Promix nails it! In fact, I am so impressed that I recommended it to health food stores in my area.”

Username “VibrandRebel,” Amazon

Ddfusc, another verified customer, feels similarly, writing, “I wanted a casein protein without any artificial sweeteners (aspartame, sucralose…). I didn’t know if I would like something that has no flavor but when I mixed this (very easy to mix, no clumps) with almond milk it just tastes like regular milk which is great. In smoothies I’ll use different frozen berries and it is awesome. Also doesn’t have any weird chemical aftertaste like you get with other proteins.”

Most negative reviews complain of a gritty texture, undissolved clumps, and chalky aftertaste when shaken or stirred into plain liquid.

Optimum Nutrition Platinum Rebuild is designed to help serious athletes reach their performance goals. It combines fast-acting whey protein with slow-digesting casein to cover all the bases for muscle growth and recovery. Creatine and glutamine are also included to help amplify these results.

Optimum Nutrition’s Platinum Rebuild provides 24 grams of protein from casein and whey sources, plus other ingredients to help maximize muscle performance and recovery. When it comes to optimizing muscle gains, getting enough total protein is the most important factor. However, different protein sources play different roles in muscle health, and you may be able to fine-tune your results by leveraging the advantages of each. ( 9 )

“This product contains whey and casein, the two types of protein found in milk. Both are complete proteins, meaning they contain all of the essential amino acids needed to support muscle growth; however, they act differently due to how they are digested,” says Mohr.

Whey is considered a “fast protein” because it digests quickly. This makes it best to consume after a workout, as it rapidly replenishes muscle protein stores, aiding muscle growth. Conversely, casein digests slowly, gradually releasing amino acids into circulation. This helps prevent muscle breakdown. By combining these protein sources, Optimum Nutrition gives you the best of both worlds. ( 10 )

Two additional ingredients are included in this product to help enhance your results: creatine monohydrate and L-glutamine.

Creatine is an amino acid shown to help improve muscle strength and performance. According to the International Society of Sports Nutrition (ISSN), three to five grams of creatine are needed daily to see benefits. Optimum Nutrition provides three grams in each serving. ( 11 )

L-glutamine is another amino acid thought to improve muscle recovery, but so far, research shows minimal effects. ( 12 ) Nonetheless, each serving of Optimum Nutrition’s formula contains three grams of this amino acid.

A full-size tub only provides 20 servings, so be prepared to order frequently. Two flavors are available: dark chocolate and vanilla buttercream.

If sustainability and clean labels are a priority for you, this may not be the best option. The ingredient list includes artificial flavors, gums, sucralose, and acesulfame-K, and there’s no indication that it’s sourced from sustainable or grass-fed sources.

At $3 per serving, Optimum Nutrition Platinum Rebuild is the most expensive on our list. However, Optimum Nutrition is highly regarded by athletes, especially for its Gold Standard whey protein, which is often considered one of the best.

Finding the right supplement that meets health goals and delivers on promised claims requires time and research. On top of that, you need to consider product safety and price.

Dedicated to helping you find the best protein powder for muscle gain, we do the leg work for you. Our team tested, evaluated, and fact-checked dozens of protein powders on the market, including over 30 casein protein powders, taking many key factors into consideration, including effectiveness, quality, safety, and price, looking for supplements that rank high in several key areas to create our list of recommendations. Learn more about our whey protein powder scoring methodology and plant-based protein powder methodology here.

We used the following criteria to score each protein powder:

The protein source is important because it affects the product’s digestibility, nutrient profile, and environmental impact. We consider the origin of the protein to ensure it meets vegan standards and provides a high-quality, sustainable option.

Here’s what we look for:

Whether the protein is complete is crucial for determining if it provides all nine essential amino acids needed for muscle repair and overall health. We consider this to ensure that the product can serve as a reliable, sole protein source without requiring additional supplementation.

The balance of macronutrients per serving is important for managing energy levels, weight, and overall nutrition. We consider these calories to evaluate if the product supports specific dietary goals, such as high-protein or low-carb diets.

Our factors in this rating include:

Our factors in this rating include:

Understanding the cost efficiency is important for those who want to manage their budget while meeting their nutritional needs. We consider the price per gram of protein to compare the value of different products.

These are the ranges we consider:

Sweeteners play a significant role in the taste, caloric content, and health impact of the product. We consider the type and amount of sweeteners used to evaluate their impact on flavor, their suitability for low-sugar diets, and any potential health implications.

Here are the common ones we evaluate:

Getting enough protein is important for overall health. According to the Recommended Daily Allowance (RDA), most people need a minimum of 0.8 grams of protein per kilogram of body weight daily, which equates to about 65 grams of protein daily for a 180-pound person. ( 7 )

However, recent research indicates that more protein may be needed to optimize health. A 2019 review suggests 1.2 to 2.0 grams of protein daily per kilogram of body weight supports athletic performance, weight management, and muscle maintenance during aging. This equals 98 to 163 grams per day for the same 180-pound person. ( 8 )

Protein powders offer a convenient way to increase your protein intake, and casein protein powders offer specific advantages. The following are a few that stand out:

To build and maintain muscle, your body needs to grow more muscle than it breaks down. Tough workouts, weight loss, aging, or illness can cause muscle breakdown. Eating enough protein helps repair and build muscles, keeping this balance in check. ( 8 )

Casein is a high-quality protein powder choice because it contains all nine essential amino acids, including branched-chain amino acids crucial for muscle building. Unlike whey protein, which acts fast, casein’s slow digestion releases amino acids steadily into the bloodstream. ( 1 )

This slow digestion ensures your muscles receive protein for up to six hours, helping to prevent muscle breakdown and safeguard muscle mass, especially during periods of fasting such as sleep. ( 1 ) For this reason, people often take it before bed to aid with overnight muscle recovery.

Research backs this up. A 2021 review showed that taking 20 to 40 grams of casein 30 minutes before bed increased overall protein production in young and elderly men overnight. Similarly, a 2020 review found that consuming at least 40 grams of casein before bed enhances muscle recovery and performance the next day. However, more research is needed to solidify these findings. ( 14 , 1 )

Due to its slow digestion, casein might be especially good at managing hunger, but studies are mixed. ( 15 )

While it’s unclear if casein is better than other proteins for hunger control, high-quality proteins like casein are known to reduce hunger, the desire to eat, and hunger-stimulating hormones. Therefore, incorporating casein into your diet can contribute to overall satiety and better appetite management. ( 16 )

Protein intakes above the RDA of 0.8 grams per kilogram of body weight per day from any source may help reduce bone density losses and the risk of features, particularly in older adults. ( 17 )

Casein protein powders can be rich in calcium, further supporting bone health. ( 2 )

Casein protein is a good choice for anyone looking to build muscle mass or increase their overall protein intake; however, it may be ideal for specific groups of people.

Due to its slow and steady release of amino acids, it may be particularly helpful to people who work out in the evening and want to promote muscle recovery overnight or who have multiple training sessions throughout the day and want a steady supply of essential amino acids.

Additionally, casein may be helpful for people who need to manage their hunger during weight loss or between long periods of eating because of scheduling demands or intermittent fasting diets. Its slow digestion may help you feel fuller longer.

If you’re looking for a protein powder to keep you full during your weight loss journey, check out our best protein powders for weight loss .

A high-quality casein protein powder should contain at least 20 grams of protein per serving, if not more. The International Society of Sports Nutrition recommends that active individuals should supplement with 20-40 grams of protein, up to every three to four hours. ( 18 ) Some research has shown that a casein protein powder dose of 40 grams taken 30 minutes before bedtime may be beneficial in helping with muscle recovery. ( 1 )

Casein protein powder may not be well tolerated by some individuals and may cause gastrointestinal side effects such as gas, bloating, and stomach pain. People who are allergic to dairy should not consume casein protein powder since it is derived from milk and would cause an allergic reaction.

Typically, a two-pound container of casein protein powder with 30 servings costs around $50 to $60. The average cost of the casein protein powders featured in our list is $1.68 per serving. The cheapest casein protein powder featured here costs $0.94 per serving, while the most expensive costs $3.00 per serving. The cost of a casein protein powder can depend on the brand and quality of ingredients.

Micellar casein is the least processed version of casein and, therefore, more likely to maintain casein’s slow-digesting benefits, though research is ongoing in this area. ( 3 , 4 ) According to our team of experts, Legion Casein+ is the best casein protein powder on the market.

One to two scoops, or 20 to 40 grams, after a workout or before bed for muscle recovery is typical. However, your ideal dose will depend on your health and fitness goals. Make sure you’re getting a variety of different proteins in your diet, and speak with your doctor about how much protein you need.

Casein protein powders are not a good choice for anyone with dairy allergies or for people looking for a vegan protein powder . Additionally, certain casein supplements may not align with Kosher or Halal diets.

Both casein and whey are quality options for increasing protein intake . Each supplies the nine essential amino acids your body requires. However, they serve different roles in your fitness regimen.

Whey is fast digesting, spiking amino acid levels quicker and higher than casein. It also contains more leucine, which triggers muscle building. ( 19 ) For this reason, it may be best used immediately post-workout to replenish fatigued muscles.

On the other hand, casein digests more slowly, providing a steady protein supply to muscles, which helps protect against breakdown and can aid in managing hunger. Due to its gradual release, it’s best suited for periods of fasting, such as overnight or during calorie-restricted diets. ( 11 )

Casein can be taken anytime, but research suggests taking it 30 minutes before bed can provide muscle health benefits overnight.

Yes, casein protein powder is generally safe, unless you are allergic to dairy. Those who are not allergic to dairy may still experience mild gastrointestinal side effects. But casein protein powder is generally well tolerated by most people. Look for a casein protein powder that is third-party tested and manufactured in a GMP or cGMP certified facility in order to ensure there are no unsafe levels of contaminants, like heavy metals, or banned substances.

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.

Chris Mohr, Ph.D., RD

Dr. Chris Mohr is an internationally recognized subject matter expert and speaker and performance coach. Through his facilitation and online resources, he works closely with some of the largest corporations in the world including Deloitte, Delta Airlines, Johnson & Johnson and more to help busy executives all over the world, develop the energy to thrive personally and professionally.

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.

MS, RDN, Fortune Recommends Nutrition Writer

Meghan is an expert Registered Dietitian Nutritionist (RDN) with a Master’s degree in Nutrition Science and over 15 years of experience in the nutrition and wellness field. A sought-after health writer, she’s committed to empowering people to lead their healthiest lives by delivering trustworthy, practical, and engaging nutrition content.