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Casein is the most predominant type of protein in milk. In fact, it represents about 80% of milk’s total protein content (1).
It’s widely used as a pre-sleep protein supplement because it’s a more slowly digested protein source, which may allow for increases in overnight muscle protein synthesis and help prevent muscle degradation while you sleep (2, 3).
Two forms of casein are commonly found in casein supplements: micellar casein, which is milk’s natural casein form, and sodium, potassium, or calcium caseinates, which are more rapidly digested.
Aside from being a more natural form of casein, micellar casein has traditionally been preferred over caseinates because of its slower digestion rate, which sustains blood amino acid concentrations overnight. However, the research is mixed (4).
Keep reading for our picks of the 12 best casein protein powders.
A quick look at the best casein protein powders
- Best overall: Optimum Nutrition Gold Standard 100% Casein
- Best with multiple flavors: Dymatize Elite Casein
- Best for blending: Kaged Muscle Kasein
- Best for sustainability: Legion Casein+
- Best certified gluten-free: Ascent Native Fuel Micellar Casein
- Best for baking: NOW Sports Micellar Casein
- Best without sugar substitutes: Promix Casein Protein Powder
- Best for post-workout recovery: BioSteel Recovery Protein Plus
- Best sugar-free: Nutricost Casein Protein Powder
- Best grass-fed: Muscle Feast Micellar Protein
- Best unflavored: Naked Casein
- Best personalized blend: Gainful
How we chose
All the products included have been vetted to ensure that they align with Healthline’s brand integrity standards and approach to well-being. You can read more about our vetting process.
Each casein protein powder in this article:
- adheres to allowable health claims and labeling requirements, per Food and Drug Administration (FDA) regulations
- is manufactured in facilities that adhere to current good manufacturing practices (CGMPs) established by the FDA
- is produced by a medically credible company that follows ethical, legal, and industry best standards
- is made by a company that provides objective measures of trust, such as having its supplements validated by third-party labs
Additional factors we considered included:
- Quality testing: We included products that are rigorously tested for quality and purity, ideally by a third-party organization.
- Casein type: The products below contain micellar casein, which research shows has a slower rate of digestion.
- Ingredient quality: We looked for products that are made with quality ingredients and contain few additives and preservatives.
- Price: We included casein powders to accommodate a range of budgets.
A note on price
General price ranges with dollar signs ($–$$$) are indicated below. One dollar sign means the product is rather affordable, whereas three dollar signs indicate a higher price range.
Generally, prices range from $1.02–$2.80 per serving, or $39–$100 per tub, though this may vary depending on where you shop and which tub size you buy.
Pricing guide
- $ = under $1.25 per serving
- $$ = $1.25–$2.00 per serving
- $$$ = over $2.00 per serving
Healthline’s picks of the best casein protein powders
Best overall
Optimum Nutrition Gold Standard 100% Casein
- Price: $
- Available flavors: Chocolate Crème and French Vanilla
Optimum Nutrition is known for being a reputable, high quality supplement brand. It’s no surprise, then, that Optimum Nutrition’s casein powder is one of the most highly recommended casein supplements.
This casein powder provides 24 grams of protein per serving, along with 4.8 grams of naturally occurring branched-chain amino acids (BCAAs) — three amino acids that help increase the rate of muscle protein synthesis (5).
In addition to being manufactured in CGMP-compliant facilities, Optimum Nutrition Gold Standard 100% Casein is Certified for Sport by NSF International, a third-party testing organization that guarantees the absence of substances banned by many major athletic organizations.
Nutrition stats for 1 scoop (37.5 grams) of the Chocolate Crème flavor (6):
- Calories: 130
- Fat: 1 gram
- Protein: 24 grams
- Carbs: 7 grams
- Added sugar: 2 grams
Pros
- made with 100% micellar casein
- free of artificial flavors, sweeteners, and colors
- available in two sizes: 2 or 4 pounds (lbs.) (900 grams or 1.8 kg)
- NSF Certified for Sport
Cons
- contains soy ingredients
- French Vanilla flavor contains inulin, which may cause gastrointestinal upset in some people
- available only in two dessert-inspired flavors
Best with multiple flavors
Dymatize Elite Casein
- Price: $$
- Available flavors: Cinnamon Bun, Rich Chocolate, Smooth Vanilla, and Cookies & Cream
If you’re looking for a protein powder that comes in dessert-inspired flavors, then you may want to consider Dymatize Elite Casein.
In addition to Rich Chocolate and Smooth Vanilla, the powder is available in Cinnamon Bun and Cookies & Cream flavors.
It’s also third-party tested by Informed Choice and manufactured in CGMP- and sport-certified facilities. However, the protein powder itself isn’t third-party tested.
Nutrition stats for 2 scoops (36 grams) of the Rich Chocolate flavor (7):
- Calories: 130
- Fat: 2 grams
- Protein: 25 grams
- Carbs: 3 grams
- Added sugar: 0 grams
Pros
- made with 100% micellar casein
- free from added sugars
- certified gluten-free
- available in two sizes: 2 or 4 lbs. (900 grams or 1.8 kg)
- available in four flavors
- third-party tested
Cons
- contains soy ingredients
- contains artificial sweeteners
- artificial flavors used in all varieties except Rich Chocolate
Best for blending
Kaged Muscle Kasein
- Price: $$
- Available flavors: Chocolate Peanut Butter, Chocolate Shake, and Vanilla Shake
According to online reviews, Kaged Muscle Kasein blends easily and has an enjoyably smooth texture.
Plus, it’s available in three dessert-inspired flavors, so it’s a great option if you’re looking for a protein powder that tastes like a milkshake.
Kaged Muscle Kasein is a good option for competitive athletes because it’s third-party tested and Informed Sport certified.
Nutrition stats for 1 scoop (35.6 grams) of the Chocolate Shake flavor (8):
- Calories: 130
- Fat: 0.5 grams
- Protein: 26 grams
- Carbs: 4 grams
- Added sugar: 0 grams
Pros
- 100% micellar casein
- contains less than 1 gram of lactose per serving
- available in three dessert-inspired flavors
- Informed Sport and Informed Choice certified
Cons
- available only in a 2-lb. (900-gram) tub
- not suitable for people with coconut allergies
- contains artificial sweeteners
Best for sustainability
Legion Casein+
- Price: $$
- Available flavors: Dutch Chocolate, Vanilla, Strawberry, and Banana Cream Pie
Legion takes pride in producing a casein protein powder — Casein+ — that’s made from milk sourced from small, sustainable Irish milk farms.
The brand works with farms that are certified by Ireland’s Sustainable Dairy Assurance Scheme, which requires adherence to high standards for animal welfare, traceability, and soil and grass management practices.
Legion Casein+ is manufactured in an FDA-approved, CGMP-certified facility.
What’s more, each product page on the company’s website includes a link to the third-party testing results, making it easy to see exactly what’s in each product before purchasing.
Nutrition stats for 1 scoop (34 grams) of the Dutch Chocolate flavor (9):
- Calories: 110
- Fat: 0.5 grams
- Protein: 25 grams
- Carbs: 3 grams
- Added sugar: 0 grams
Pros
- 100% micellar casein
- doesn’t contain artificial food dyes
- available in four flavors
- free worldwide shipping when you order through Legion’s site
- third-party testing results available online
Cons
- Strawberry flavor contains erythritol, a sugar alcohol that may cause gastrointestinal upset in some people
- not NSF Certified for Sport or Informed Sport certified
Best certified gluten-free
Ascent Native Fuel Micellar Casein
- Price: $$
- Available flavors: Chocolate, Vanilla Bean, and Chocolate Peanut Butter
While some protein powders state that they’re made without gluten, Ascent Native Fuel Micellar Casein stands out because it’s certified gluten-free by the Gluten-Free Certification Organization, which requires that tested products contain 10 or fewer parts per million of gluten.
This certification guarantees that the product is free from gluten and cross contamination — an important distinction for those who require a gluten-free diet for the management of gluten-related disorders such as celiac disease.
Ascent supplements are known for being the benchmark of product purity. They’re also Informed Sport certified, so they’re a good option for competitive athletes.
Nutrition stats for 1 scoop (36 grams) of the Chocolate flavor (10):
- Calories: 120
- Fat: 1 gram
- Protein: 25 grams
- Carbs: 4 grams
- Added sugar: 0 grams
Pros
- 100% micellar casein
- certified gluten-free
- free from artificial ingredients
- available in two sizes: 2 or 4 lbs. (900 grams or 1.8 kg)
- available in three flavors
- Informed Sport certified
Cons
- produced on equipment shared with peanuts and tree nuts, which may be a concern for those with a tree nut or peanut allergy
- on the pricier side
Best for baking
NOW Sports Micellar Casein
- Price: $
- Available flavors: Unflavored
Made from high quality casein powder and available in an unflavored variety, NOW Sports Micellar Casein is one of the best options if you prefer to add protein powder to your favorite baked goods.
For example, you can try adding this protein to pancakes, waffles, or muffins for a protein-rich breakfast. It can also be used in sweet snacks and treats, such as your favorite energy bites or edible raw cookie dough.
NOW Sports Micellar Casein is manufactured in CGMP-compliant facilities and is Informed Sport certified.
Nutrition stats for 1 scoop (24 grams) (11):
- Calories: 90
- Fat: 0.5 grams
- Protein: 19 grams
- Carbs: <1 grams
- Added sugar: 0 grams
Pros
- made from micellar casein
- does not contain artificial sweeteners or other additives
- Informed Sport certified
- works well for baking and mixing into other foods
Cons
- only one size available
- available only in an unflavored variety
Best without sugar substitutes
Promix Casein Protein Powder
- Price: $$
- Available flavors: Unflavored, Chocolate
This casein powder is unique because it’s made without sugar substitutes.
The Unflavored option is sugar-free, while the Chocolate flavor is sweetened with organic coconut sugar.
Users report that the powder is gentler on the stomach than other powders, though some also mention that it has a grainier texture.
Promix protein powders are third-party tested for purity and potency. In fact, the company’s website offers a search feature that allows you to see where each batch of protein powder was tested.
However, while the company’s creatine and vegan protein powders are NSF Certified for Sport, its casein protein powder is not.
Nutrition stats for 2 scoops (29 grams) of the Unflavored version (12):
- Calories: 105
- Fat: 0 grams
- Protein: 25 grams
- Carbs: 0 grams
- Added sugar: 0 grams
Pros
- 100% micellar casein
- free of soy, gluten, and artificial sweeteners
- available in two sizes: 2 or 5 lbs. (900 grams or 2.3 kg)
- offers refill packaging when ordered from the Promix website
- third-party tested
Cons
- not NSF Certified for Sport or Informed Sport certified
- limited flavor options
Best for post-workout recovery
BioSteel Recovery Protein Plus
- Price: $$$
- Available flavors: Chocolate, Vanilla
BioSteel offers a recovery protein blend made up of whey protein isolate and micellar casein.
The blend also contains added leucine, an essential amino acid that plays a role in muscle protein synthesis, as well as carbohydrates, which may help with recovery and glycogen repletion (13, 14).
The powder contains digestive enzymes, which may be beneficial for certain populations, such as those who lack sufficient digestive enzymes. However, the research on the benefits of these enzymes is limited and inconclusive (15).
BioSteel Recovery Protein Plus is NSF Certified for Sport and comes in Vanilla and Chocolate flavors.
Nutrition stats for 2 scoops (72 grams)of the Chocolate version (16):
- Calories: 250
- Fat: 1 gram
- Protein: 24 grams
- Carbs: 37 grams
- Added sugar: 0 grams
Pros
- NSF Certified for Sport
- certified gluten-free
- contains whey and casein
- higher in calories than others on this list
Cons
- high in added sugar with 14 grams per serving
- available in only two flavors
- expensive
Best sugar-free
Nutricost Casein Protein Powder
- Price: $$
- Available flavors: Chocolate, Vanilla, and Unflavored
If you’re looking for a sugar-free protein powder and don’t mind artificial sweeteners like sucralose, then Nutricost Casein Protein Powder is worth considering.
Both the Chocolate and Vanilla flavors are artificially flavored and sweetened, though they still get positive customer reviews for their taste and texture.
This powder from Nutricost is manufactured in a CGMP-compliant, FDA-registered facility. It’s also third-party tested, though the name of the testing organization isn’t disclosed.
Nutrition stats for 1 scoop (30 grams) of the Unflavored version (17):
- Calories: 110
- Fat: 0 grams
- Protein: 24 grams
- Carbs: 0 grams
- Added sugar: 0 grams
Pros
- 100% micellar casein
- certified gluten-free
- available in two sizes: 2 or 5 lbs. (900 grams or 2.3 kg)
- third-party tested
Cons
- artificial flavors and sweeteners in the Chocolate and Vanilla flavors
- not NSF Certified for Sport or Informed Sport certified
Best grass-fed
Muscle Feast Micellar Casein
- Price: $
- Available flavors: Chocolate, Vanilla, and Unflavored
Muscle Feast Micellar Casein is a certified gluten-free product that’s made in a CGMP- and FDA-compliant facility. It comes in three varieties: Chocolate, Vanilla, and Unflavored.
Most notably, the product is sourced from grass-fed cow’s milk, which Muscle Feast defines as “grass and forage feed only” throughout the animal’s lifetime.
Muscle Feast products are third-party tested and made in an FDA-compliant facility.
Nutrition stats for 1 scoop (24 grams) of the Chocolate flavor (18):
- Calories: 88
- Fat: 0.5 grams
- Protein: 19 grams
- Carbs: 1.2 grams
- Added sugar: 0 grams
Pros
- 100% micellar casein sourced from grass-fed cow milk
- comes in two sizes: 2 or 4 lbs. (900 grams or 1.8 kg)
- certified gluten-free
- third-party tested
Cons
- contains sugar substitutes
- not NSF Certified for Sport or Informed Sport certified
Best unflavored
Naked Casein
- Price: $$
- Available flavors: Unflavored
Naked casein is made from 100% micellar casein and is our pick for best unflavored option because it contains no additional ingredients.
If you need to steer clear of soy, artificial ingredients, and sugar substitutes, then this casein powder is for you.
Additionally, Naked Casein is a certified gluten-free product, so it’s suitable for those who need to follow a strict gluten-free diet.
While Naked Casein is third-party tested, this product is not certified safe for sport.
For those who prefer a flavored protein powder, Naked Casein also comes in Chocolate and Vanilla flavors, both of which are naturally sweetened with coconut sugar and contain minimal ingredients.
Nutrition stats for 2 scoops (30 grams) of the Unflavored version (19):
- Calories: 110
- Fat: 0 grams
- Protein: 26 grams
- Carbs: 0 grams
- Added sugar: 0 grams
Pros
- also comes in Vanilla and Chocolate
- contains just one ingredient
- third-party tested
- certified gluten-free
Cons
- not certified safe for sport
Best personalized blend
Gainful
- Price: $–$$$
- Available flavors: unflavored with the option to select from nine flavor boosts: Strawberry Cream, Madagascar Vanilla, Rich Chocolate, Caffè Mocha, Cookies & Cream, Chocolate Peanut Butter, Matcha Green Tea, Cinnamon Toast, and Sea Salt Caramel
Gainful is a personalized protein powder company that uses the results of an online questionnaire to create a protein powder blend designed to meet your unique nutritional needs and fitness goals.
Gainful protein powders are unflavored and come with four flavor boosts, allowing you to easily change the taste of your protein shake each day.
The company’s products are manufactured in a CGMP-approved facility, though they aren’t third-party tested or certified safe for sport.
The nutrition facts vary depending on your customized blend. However, the company’s website states that most powders contain 19–27 grams of protein per serving.
Pros
- fully customized based on your needs and preferences
- includes access to a registered dietitian
- unflavored powder that comes with four flavor boosts
Cons
- more expensive than other protein powders
- custom blend may not be 100% casein-based
- not NSF Certified for Sport or Informed Sport certified
- not third-party tested
Comparison of the best casein protein powders
Here’s a quick look at how our top picks compare:
-Price rangeFlavorsProtein per servingThird-party testedCertified safe for sportGood forOptimum Nutrition Gold Standard Naturally Flavored 100% Casein$• Chocolate Creme• French Vanilla24 gramsyesyesserious athletes looking for an NSF Certified for Sport productDymatize Elite Casein$$• Rich Chocolate• Cinnamon Bun• Cookies & Cream• Smooth Vanilla25 gramsyesnobudget-conscious athletes and fitness enthusiastsKaged Muscle Kasein Isolate$$• Chocolate Peanut Butter• Vanilla Shake• Chocolate Shake25–26 gramsyesyesblending into a smoothie or dessert shakeLegion Casein+$$• Milk Chocolate• Strawberry• Vanilla• Banana Cream Pie25–26 gramsyesnopeople who are eco-consciousAscent Native Fuel Micellar Casein$$• Chocolate• Vanilla Bean• Chocolate Peanut Butter25 gramsyesyespeople who follow a gluten-free diet and are looking for a high quality, Informed Sport-certified casein powder Now Sports Micellar Casein$Unflavored19 gramsyesyespeople who prefer to mix casein powder into baked goodsPromix Unflavored Casein Protein Powder$$• Unflavored• Chocolate25–26 gramsyesnoa naturally sweetened powder without sugar substitutesBioSteel Recovery Plus$$$• Chocolate• Vanilla24 gramsyesyesmuscle building and post-workout recoveryNutricost Casein Protein Powder$$• Chocolate• Vanilla• Unflavored24–25 gramsnonopeople looking for an affordable optionMuscle Feast Micellar Casein$• Chocolate• Vanilla• Unflavored 19 grams yesnopeople who follow a gluten-free diet or prefer casein sourced from grass-fed cowsNaked Casein$$• Chocolate• Vanilla• Unflavored26–27 gramsyesnopeople who prefer an unflavored powder with only one ingredientGainful$–$$$unflavored with optional flavor boosts:• Strawberry Cream• Cinnamon Toast• Sea Salt Caramel• Madagascar Vanilla• Caffè Mocha• Chocolate Peanut Butter• Cookies & Cream• Matcha Green Tea• Rich Chocolate19–27 gramsnonopeople looking for a personalized formula with expert guidanceHow to choose a casein protein powder
There are several factors to consider when shopping for a casein protein supplement:
- Third-party testing: Choosing a casein protein powder that has been third-party tested is the best way to ensure purity and potency. While third-party testing doesn’t guarantee product safety, it does help ensure that the label accurately reflects the contents.
- Safe for sport: Competitive athletes should choose a product that’s Informed Sport certified or NSF Certified for Sport to ensure that the supplement is free from substances that are banned by most sporting organizations (20).
- Form of casein: If you’re looking for a protein powder that digests slowly, it may be worth choosing one with micellar casein. While results are mixed, some research suggests that micellar casein is more slowly digested than other forms of casein, though processing and storage may greatly impact the rate of digestibility (4).
- Presence of additives: Casein powders vary widely in composition. Some may contain food additives or other ingredients, such as added sugars, probiotics, or artificial sweeteners. Consider these ingredients in the context of your diet as a whole.
- Quantity of protein: Check the grams of protein per serving of casein, as this can vary among brands. Research suggests that a dose of at least 30 grams of casein is optimal for muscle growth (2, 21).
- Calorie content: Casein supplements vary widely in total calorie content. Choose a supplement that best fits your calorie needs and weight goals.
Benefits of casein protein powder
The primary benefit of casein protein powder supplements is to provide a source of protein that’s easy to consume.
Casein supplements are often marked as being beneficial for muscle repair and recovery when taken before bed. However, the overnight benefits of casein have recently been called into question.
A recent study of resistance-trained men found that pre-sleep casein supplementation did not enhance muscle recovery but did reduce feelings of hunger the morning after supplementation (22).
“While this study was a small and short duration study, it certainly points to the limited benefits of casein before bed,” explains Dr. Rachele Pojednic, PhD, assistant professor and program director of exercise science at Norwich University.
Despite this, Pojednic says there is still a benefit to taking casein: “Casein has an excellent essential amino acid profile, is highly digestible, and is still a great source of overall protein.”
While research is mixed on the benefits of casein for muscle protein synthesis, casein can still offer all the benefits protein provides. “Protein is essential for life and critically important for physiologic functions outside of muscle protein synthesis,” explains Pojednic.
In addition to being an excellent source of protein, casein is a good source of BCAAs.
“The BCAAs, particularly leucine, have been shown to be critically important for muscle protein synthesis,” Pojednic says.
Still, keep in mind that leucine needs to be paired with a regular resistance training regimen for optimal effectiveness.
Additionally, taking BCAAs alone is not as effective as consuming BCAAs along with all the essential amino acids.
“When examining the BCAAs in isolation compared to complete proteins such as whey or casein, those that contain all of the EAAs have much more beneficial and synergistic effects overall,” says Pojednic.
This is another reason that choosing a casein protein powder is more beneficial than taking BCAAs alone.
Potential side effects
Casein protein powders are generally considered safe. However, the FDA does not regulate the safety, quality, and accuracy of supplements as strictly as it does for other products, such as pharmaceuticals.
Third-party testing is the most important consideration when choosing any supplement to ensure that the product contains what is listed on the label and is free of other contaminates.
Concerns have also been raised about heavy metal presence in protein powders. A study by the Clean Label Project found that 40% of the 134 protein powders tested contained high levels of heavy metals (23).
However, these results were called into question, and further investigation found that the amounts of heavy metals in the protein powders tested do not pose a risk to human health in quantities normally consumed (24, 25).
As is the case in much of nutrition science, more isn’t always better when it comes to nutrients.
While there is limited research on the effect of taking casein in excess, some research suggests that general protein intake in excess of daily needs does not provide a benefit to muscle protein synthesis or recovery (26).
Finally, keep in mind that some people do have casein allergies, which can result in symptoms such as hives and vomiting.
Frequently asked questions
Is casein protein powder safe?
Casein protein powder is generally considered safe for healthy adults.
However, people who are currently taking medications, have a medical condition, or are pregnant or nursing should talk with a healthcare professional before taking any new supplements.
Does casein make you gain weight?
Casein protein powder could lead to weight gain if adding it to your diet causes you to regularly consume more calories than you burn.
However, simply consuming casein protein powder is unlikely to cause weight gain on its own.
What happens if you take too much casein?
Any protein consumed in excess, including casein, will be stored as fat or excreted depending on total energy needs and daily intake.
Additionally, casein protein powder is not intended to act as a weight loss supplement or meal replacement. Therefore, there’s a potential risk of nutrient deficiencies if you’re regularly consuming casein supplements in place of nutrient-rich foods.
The bottom line
Casein is a slowly digested protein that may allow your body to repair your muscles while you sleep, which could promote muscle recovery.
Milk and other dairy products contain varying amounts of casein. If you’re looking for a whole-food source of casein, drinking milk may be the easiest and least expensive way to add it to your diet.
Pojednic also recommends an unexpected source of casein: cheese.
“Casein is the protein that causes milk to produce curds, the precursor to making cheese,” she says. “So, if you want an all-natural source of casein you can carry with you as a snack, just go find those yummy, salty, squeaky cheese curds in the dairy aisle!”
If you’re looking to add casein via a casein protein powder, make sure to choose a product that meets your specific preferences and needs regarding flavor, quality, and calorie content.