Mixing Protein Powders Together: Avoid These 3 Things

I test and review a lot of whey protein powders for FeastGood.com. 

After those articles get published, I have a kitchen filled with random bottles of protein.

So sometimes, I like to mix different brands together. 

However, when my husband saw me doing that, he wondered if that was safe or not.  

Here’s my quick take:

You can mix protein powders together if you want to reap the benefits of two different types of protein (whey + casein), improve the taste of your protein shake, or improve the amino acid profile of your shake.

With that said, there are definitely a few things to avoid when mixing whey proteins together, which I’ll share below.

Key Takeaways

  • Ensure you’re using products that you trust and that have been third-party tested.
  • When you’re mixing protein powders together it should always be to elevate the quality or taste of your protein.
  • The best combination of proteins for those who want a protein right after working out is Whey Hydrolysate + Whey Isolate

Is It Safe To Mix Two Different Protein Powders?

Yes, it is safe to mix two different protein powders as long as you’re using protein powders that genuinely contain the ingredients that they claim to have in the doses indicated on the label.

Here are two tips to follow to ensure you’re being safe when mixing protein powders:

Make Sure Both Are 3rd Party Tested

Protein powders are not regulated by the FDA so many supplement companies cut corners by using cheap fillers rather than high-quality ingredients. 

For this reason, I always recommend going for protein powders that have been third-party tested for ingredients quality and label accuracy.

If a product is Third-party certified it means that the protein is tested by an outside party and has been confirmed to be exactly what it claims to be.

You can tell if your protein powder is tested if the tub of protein has a logo that states that it is third-party tested or by reaching out to the company directly and asking them whether it is third-party tested. 

Some supplement companies, like Transparent Labs, actually let you see the testing results from your specific tub of protein.

Make Sure You Try Each Separately First

I also recommend trying each product separately first to ensure that you can tolerate it without any digestive issues before combining them.

This is because you may have sensitivities to certain types of sweeteners that are used in protein powder and each protein brand may include more or less of certain sweeteners.  

The same thing goes for lactose. If you have a lactose sensitivity, know that different types of protein powders can have anywhere from zero to moderate amounts of lactose.  

The higher the ‘whey protein concentrate’ content vs ‘whey protein isolate’ content, the more lactose there will be.  

Are There Benefits of Mixing Protein Powders?

Are there benefits of mixing protein powders?

There are many benefits to mixing protein powders together, including:

1. Reaping The Benefits Of Each Type Of Protein

The main benefit of mixing different types of protein is that each type of protein has slightly different benefits, so combining them can increase the benefits.

By mixing proteins from different sources, you can safely harness the benefits from each individual protein source.

Jim Stoppani, Exercise Physiologist

For example, whey is known for being fast-absorbing to supply the body with amino acids more quickly, whereas casein is known for being slower-absorbing to provide a more steady stream of amino acids over a longer period.

By combining the two you get the benefits of both fast and slow-digesting proteins. 

This is ideal if you’re someone who works out before going to bed because you’ll begin repairing muscle damage quickly thanks to the whey, but you’ll also encourage muscle protein synthesis (muscle growth ) overnight thanks to the casein.

Many supplement companies have started to take advantage of this by manufacturing blends of casein and whey. 

My favorite is PEScience’s whey + casein blend called Select Protein (click to read my review).

2. Forming Complete Proteins

One of the main reasons why you should consider mixing protein powders is if you’re using plant-based protein powders because many of them aren’t “complete proteins”. 

This means they don’t have all the amino acids that your body needs to build muscle effectively.

Protein sources are made up of amino acids that your body uses to build muscle and support other bodily functions. There are 9 essential amino acids that your body doesn’t produce on its own and therefore must get from food. 

Foods that are considered “complete” contain all 9 of these amino acids in sufficient quantities. Foods that are considered “incomplete” do not contain all of the 9 essential amino acids in sufficient quantities.

Animal-based proteins like meat, fish, and dairy are complete proteins so they are used more effectively by the body for muscle-building.

Plant-based proteins like pea and brown rice proteins aren’t complete proteins on their own so they will not stimulate muscle protein synthesis (a precursor for muscle growth).

However, when mixed with other incomplete sources or complete plant-based proteins that contain the amino acids they’re lacking, they can become complete.

Some common plant-based proteins that form complete proteins are:

  • Pea Protein (incomplete) + Brown Rice Protein (incomplete)
  • Pea Protein (incomplete) + Hemp Protein (complete)
  • Brown Rice (incomplete) + Hemp Protein (complete)
  • Pea Protein (incomplete) + Soy Protein (complete)
  • Brown Rice Protein (incomplete) + Soy Protein (complete)

It should be noted that if you’re using a “complete” plant-based protein powder, like hemp or soy protein, then you wouldn’t need to mix it with other protein powders but you may want to if you have an incomplete protein on hand that you want to use up.

3. Improving The Taste Of Your Protein Shake

Another benefit of mixing protein powders together is that it can improve the taste of your protein shake if you have a protein on hand that you don’t enjoy or that you’re getting tired of.

I found myself doing this recently because I was reviewing Naked Protein, which doesn’t taste as good as I wish it did but has solid ingredients. 

So rather than wasting a high-quality tub of protein, I mixed it with another protein that I love the taste of (Alani Nu) to make it more enjoyable.

You could even do this with two flavors of protein that you really like just to create a different flavor profile for more variety. 

I really like combinations of: 

  • Coffee and chocolate
  • Chocolate and cookies & cream
  • Cookie dough and cinnamon.

The vessel (liquid or food) you mix with your protein powder also plays a role in how good your protein tastes, for more ideas check out my article “What To Mix Protein Powder With”.

4. Getting A Full Serving Of Protein When You’re Running Low

Lastly, mixing protein powders can be really helpful if you’re finishing a tub of protein and don’t quite have enough left of that particular brand or type of protein to get a full serving. 

For example, if you’re scraping the bottom of the bottle and only get ½ scoop of protein, you can combine it with ½ scoop of another protein to get the full serving you need.  

Avoid These 3 Things If You’re Going To Mix Protein Powders

Although there are plenty of benefits to mixing protein powders, there are 3 things you should avoid:

  • Avoid mixing incomplete proteins with other proteins that don’t form complete proteins. If you’re mixing plant-based proteins that don’t complement one another then you’re not doing your muscles any favors.  Stick to the combos I mentioned above.
  • Avoid mixing low-quality protein powders with other low-quality protein powders. If you’re going to use a lower-quality protein, like Six Star, then you should at least be mixing it with a protein powder that elevates the quality of your protein shake.
  • Avoid mixing flavors that don’t go together. Although switching up the flavor profile of your shake can keep you from getting bored, if you’re pairing two flavors that just do go together then it could make for a disgusting shake (i.e. fruity pebbles + coffee flavors)

Best Types of Protein Powders To Mix 

The best types of protein powders to mix depend on when you take your protein and your dietary preferences.

The best combination of proteins for those who want a protein right after working out

  • Whey Hydrolysate + Whey Isolate. Combining the two fastest-digesting types of protein is ideal for delivering amino acids to your muscles at a faster rate to encourage muscle recovery.

The best combination of proteins for those who want a protein powder to keep them full and encourage muscle growth

  • Whey Protein (any type) + Casein. Whey protein digests fast to deliver amino acids quickly, and the casein protein digests slower to keep you satisfied for longer and provides a steadier stream of amino acids to your muscles.

The best combination of protein for those who can’t tolerate dairy or those who want a lower-calorie protein blend

The best combination for those who require or prefer plant-based protein

  • Pea protein + Brown Rice Protein. These two plant-based proteins combined form a complete protein that is ideal for those who want to stick to plant-based protein sources.

One Drawback of Mixing Protein Powder Together

The one major drawback of mixing protein powders together is that it could mess with the texture of your protein shake. 

When you’re mixing two different products together it could cause more chunkiness or grittiness than you want in a protein shake.

Although this could probably be avoided by mixing your protein shake with a frother or in a blender, if you’re mixing your protein by stirring it in or in a shaker cup then it may not be enough to keep your shake from clumping.

Other Protein Powder Resources


Emily Arentson-Lantz and others, A Moderate Serving of a Lower-Quality, Incomplete Protein Does Not Stimulate Skeletal Muscle Protein Synthesis, Current Developments in Nutrition, Volume 5, Issue Supplement_2, June 2021, Page 487, https://doi.org/10.1093/cdn/nzab041_002

About The Author

Amanda Parker

Amanda Parker is an author, nutrition coach, and Certified Naturopath.  She works with bodybuilders, Olympic weightlifters, and powerlifters to increase performance through nutrition and lifestyle coaching.

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