The 5 Best Casein Protein Powders of 2022, According to a Registered Dietitian

How We Select Supplements

Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here. 

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. We prioritize products that are third-party tested and certified by one of three independent third-party certifiers: USP, NSF, or ConsumerLab. When relevant, we also prioritize non-GMO, organic, and products free of unnecessary and potentially harmful additives. 

It's important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.

What to Look For in Casein Protein Powders

Third Party Testing

 Supplements that are third-party tested 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. However, it’s important to note:

• Third-party testing does not test to see if a product is effective or safe for everyone, and it does not ensure the supplement will not interact with other supplements or medications.
• Not all third-party testing is created equal. It is not uncommon for supplement companies to pay labs for certificates after conducting minimal to no testing. 
• The third-party certifications we can trust are: ConsumerLab, NSF, and USP. However, these certifications are difficult to obtain and/or expensive for manufacturers, so many companies choose not to get their products tested by one of these three organizations. 
• Sometimes products tested by these three companies are more expensive to try to offset the cost they pay for certification.
• Just because a supplement is not tested by one of these three companies, it does not mean it’s a bad product. We recommend doing some research on the reputability of the manufacturer and calling up the manufacturer and their testing lab to determine their protocols and decide if you feel comfortable consuming the supplement.

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.

Heavy metal contamination is only a concern if the amount ingested is over a certain limit. It’s helpful to note that many foods in our diet naturally contain heavy metals that we consume every day at safe levels. A casein protein that has been third-party tested 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.

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.

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.