Is a Casein Protein Powder Supplement Beneficial?

Protein needs vary based on a number of factors, including age, gender, activity level, and health status. However, most Americans get adequate protein through diet alone—which looks like 46-56 grams of protein per day, or about 0.8 grams of protein per kilogram of body weight. Those who benefit from casein protein powder may include the following:

• Athletes: Many athletes need more protein than the average person due to their high activity level. The additional protein in an athlete’s diet helps support muscle growth and recovery—sometimes taken in conjunction with creatine to boost muscle growth. Because of this, athletes are the main group of people who may benefit from taking a casein protein powder supplement if they cannot get enough protein in their diet.
• Those who prefer protein supplements later in the day: Research shows that consuming milk-based protein after a workout can help promote muscle growth and recovery. Whey protein may be a better option if you want to take your protein supplement right before or after a workout since it gets broken down and absorbed faster than casein. If you prefer to have your protein supplement later in the day or before bedtime, we recommend opting for casein due to its slow absorption rate.

Who May Not Benefit from Casein Protein Powder

These groups may not benefit from taking a casein protein supplement:

• Healthy adults meeting their protein needs through diet: For the average person who is meeting their protein needs with food, a protein powder supplement is not necessary and won’t provide noticeable benefits.
• People on protein-restricted diets: There are certain medical conditions that require a person to eat a low protein diet, including chronic kidney disease and inherited metabolic disorders like phenylketonuria, homocystinuria, maple syrup urine disease, and tyrosinemia. If you need to limit protein in your diet, you should avoid using protein powder in general.
• Older adults: As we get older, we naturally lose muscle mass and strength. One way to combat this is by increasing protein intake as we age, which is particularly effective when combined with resistance training. When it comes to protein supplementation for older adults, faster-absorbing protein sources (like whey protein) may promote muscle growth more effectively than casein, a slow absorbing protein. For this reason, we recommend whey over casein for older adults. You may find it helpful to explore our roundup of the best whey protein powders.
• People with a milk allergy: A milk allergy is an immune system reaction to milk proteins and is treated by avoiding milk and products that contain milk proteins. Since casein is one of the main proteins in milk, those with a milk allergy should avoid using casein protein powder. 
• People on a vegan diet: Casein is an animal-based protein, so it does not fit into a vegan diet. If you are following a vegan diet, choose one of the many types of vegan protein powders instead of casein protein.

How We Select and Test Supplements

Our team works hard to be transparent about why we recommend certain supplements. We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest-quality products. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend. You can read more about our dietary supplement methodology here. 

In addition to our research, we tested 25 of the top casein protein powders, preparing and serving them as directed by the manufacturer. When testing, we evaluated each product for the following six critical criteria:

• Nutrition: Our nutrition editors analyzed each product based on the quality of ingredients, amount of protein and type, and other nutrients added. We also considered independent verification and associated certifications.
• Flavor: We tasted each product, noting how accurate it was to the flavor advertised on the packaging and if the flavor corresponded to the color of the drink. We also took notes on whether the flavor was good or bad, how strong each flavor was, and if we felt it was overly sweet or salty.
• Texture: We reviewed the texture of each product, noting if it was thin and smooth, clumpy, grainy, separated, or otherwise unpleasant. We reviewed the dissolubility of the product, noting how long it took to dissolve in water or milk (and if it dissolved completely), how much stirring was required, and if there was any product left at the bottom of the glass. We also tested some products in different scenarios, like when mixing into oats or pancake/waffle mixes.
• Aftertaste: We tested to see if any of the products left an aftertaste in the mouth after drinking it and noted if it was unpleasant, how long it lingered, and if we had to eat or drink something afterward to mask the aftertaste.
• Smell: Upon opening the product, we noted how it smelled, including if there were any salty, sweet, or chemical smells. We also noted any pleasant or unpleasant aromas. We reviewed if the smell was consistent with the flavor listed on the packaging and if the smell impacted the taste when we drank it.
• Value: We assessed the value, analyzing the cost in the context of the quality of the product, use and taste experience, the number of servings per container, and the shelf life.
  

What to Look For in Casein Protein Powders

• Independent verification: Protein powders that are independently verified are sent to a lab where they are tested to ensure they contain what they say they contain and are not contaminated with specific high-risk, common contaminants. Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here. If you are an athlete, look for a product that is certified NSF for Sports or Informed Sport Certified. Most protein powders naturally contain heavy metals in trace amounts, and consumers have expressed concern about heavy metal contamination when using these supplements. However, a recent study shows that consuming one to three servings of protein powder per day is unlikely to cause adverse health effects. A casein protein that has been independently verified helps ensure heavy metals do not exceed the FDA-established levels for contamination.
• Form: You might have noticed that four of the five recommended products on this list are made with “micellar” casein. This means that the milk used to make it has been microfiltered, which leads to a better-tasting product with a more pleasant consistency. Most casein protein powders are made with micellar casein because of this, so you get a more palatable product for protein shakes, smoothies, and more.
  
• Other ingredients: If you are sensitive to certain sugars, flavors, additives, or preservatives, you'll want to check the ingredient list before making your pick. Some people may experience digestive upset or bloating when consuming sugar alcohols, so be mindful of this.

Ingredients and Potential Interactions

It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking. While some combinations may yield health benefits, such as mixing creatine with protein supplements, others may have the opposite effect.

Because casein is a milk product, you should avoid it if you have a milk allergy.

Dosage

The Recommended Dietary Allowance (RDA) for protein for an average adult is 0.8 grams of protein per day per kilogram of body weight or about 46 grams of protein per day for women and 56 grams of protein a day for men. Research shows that Americans, on average, are getting more than enough protein in their diets—women are getting about 69 grams a day, and men are getting 100 grams a day, on average.

Though people meet their protein needs through food alone, individual needs vary based on different factors. Casein protein powder can help supplement your protein intake if you find it difficult to meet your protein requirements through your diet.

How Much Is Too Much?

There is no Tolerable Upper Limit (UL) for protein intake. The risk appears to be very low for consuming excess protein from food. But with such limited data to show any adverse effects of a high-protein diet from food and supplements, it is not recommended to consume more than the recommended range of protein for the average person.

Other Casein Protein Powders We Considered

• Transparent Labs Casein Protein: This powder has a great taste, no added sugars, and 100 percent grass-fed cattle as its only source of casein, but some flavors have higher contents of sodium, and it’s pricey compared to similar options.
• Optimum Nutrition Gold Standard 100% Micellar Casein Protein Powder: This powder is formulated with 24 grams of protein and 9 grams of essential amino acids per serving, plus magnesium and 100 percent of your daily value of zinc. However, the flavor options are limited, and it contains artificial sweeteners, soy, and gums.
• Muscle Feast Micellar Casein: This gluten-free and vegetarian powder has 21 grams of protein per serving, but it contains artificial sugars.

Our Experts

• Shushy Rita Setrakia, MS, RD: a Registered Dietitian and one of our nutrition and supplement editors. Shushy is passionate about converting nutrition science into meaningful dietary recommendations. She has an eye for spotting the latest nutrition trends, research, and breaking down what that can mean for your supplement and food choices.
• DJ Mazzoni, MS, RD, CDN, CSCS, a registered dietitian and certified strength and conditioning specialist

Frequently Asked Questions

What are the drawbacks of using casein protein powder over other options?

The choice to use casein protein powder over other options mostly comes down to the timing and when you plan to use the protein powder. For the same reason that casein is a slow-digesting protein, “it's a suboptimal choice for pre-workout or mid-workout protein supplementation. It won't be metabolized as quickly as other types of protein like whey, and won't be able to deliver nutrition that enhances workouts as optimally as other types of protein,” says Mazzoni.

What are the benefits of using casein protein powder over other options?

Since casein is a milk protein, it contains all nine essential amino acids—this makes it a higher quality protein source than some incomplete proteins like rice protein powder. It’s also an excellent source of calcium, an important mineral for bone and teeth health, muscle and nerve functioning, and more.

Compared to whey protein, casein is digested and absorbed much more slowly. This “makes it an optimal choice for post-exercise muscle recovery. Consuming casein protein at night before sleep helps the muscles recover from an intense workout and be better prepared for a workout the following day,” says Mazzoni.

What can I make using casein protein powder?

Casein can be used like other protein powders to make protein shakes when mixed with water or milk. It will also blend well into smoothies. 

Casein protein powder is quite absorbent and thickens when mixed with liquid to make a thick protein pudding. Because casein is so absorbent, it isn’t the best protein powder to bake with. It will work best for no-bake options like shakes, protein pudding, yogurt, or overnight oats.

Is casein protein powder better than vegan protein powder?

This depends largely on the type of vegan protein powder and what you want from a protein powder. If the vegan protein powder you use is a complete protein source with all nine essential amino acids, it will be of a similar quality to casein protein powder.

Similar to whey protein, vegan protein powders are digested and absorbed more quickly than casein. So vegan protein powder may provide some advantage over casein if you plan to use it pre-, mid-, or directly post-workout.

How expensive is casein?

Casein protein powder pricing can fluctuate based on the global supply and cost of milk. As milk pricing increases, the cost of casein protein can increase. Currently, a general range of cost per serving for casein protein powder can be around $0.90 per serving to $2 per serving.

Why Trust VeryWell Fit

Alex Aldeborgh, MS, RD, is a Verywell Fit writer and a registered dietitian with her own private practice. Alex spends her time developing healthy recipes and nutrition content for her successful blog and Instagram page, Daisybeet. Alex inspires readers to get in the kitchen to prepare healthy, inexpensive, and simple recipes. Through her experience taste-testing in recipe development, she has also developed a keen taste for different protein powders on the market.

Eliza Savage, MS, RD, CDN, is the former Editorial Director of Verywell Fit, a registered dietitian, and a published author. She used to manage all content at Verywell Fit and helped ensure that the recommended nutrition and ingestible products were dietitian-approved.

Both authors considered testing insights while creating this list.