What causes protein shake diarrhea? 

If you are wondering what causes protein shake diarrhea, you have come to the right place. Learn how to supplement your dietary protein intake without upsetting your stomach.

This article was written by Jack Schrupp.

Protein shakes and diarrhea

Can protein shakes cause diarrhea?

If you find yourself rushing to the bathroom after drinking a protein shake, you are not alone. Many people experience what commonly known as protein shake diarrhea, or loose and watery bowel movements shortly after consuming a protein shake.

While these symptoms typically subside within a few hours, some folks have reported dealing with protein shake diarrhea for several days. The good news is that despite being a common side effect, protein shake diarrhea is entirely avoidable. Keep reading to learn how to pick a protein supplement that will not cause diarrhea.


How to avoid protein shake diarrhea

Here are the ingredients that, when avoided, significantly decrease the likelihood of protein shake diarrhea and other digestive issues:

Avoid food additives

Food additives like emulsifiers, thickeners, and flavors tend to draw water into the colon, thereby increasing the liquid content of the stool. This happens because additives are hard to digest and create something called a high osmotic load.

When the osmotic load is high, there is more osmotic pressure, which is the pressure exerted by a solvent (usually water) as it moves across a semipermeable membrane (in this case the colon) in order to balance the concentration of solutes on each side of the membrane. 

Here is a list of the most common food additives in protein supplements:

acacia fiber, acacia gum, artificial flavors, ascorbic acid, aspartame, calcium carbonate, carrageenan, cellulose gum, dextrin, dicalcium phosphate, dipotassium phosphate, gellan gum, guar gum, gum arabic, inulin, locust bean gum, maltodextrin, mono- and diglycerides, ‘natural’ flavors, rice bran extract, rice dextrin, rice hulls, rosemary extract, silica, silicon dioxide, sodium alginate, sodium bicarbonate, soluble corn fiber, soy lecithin, sunflower lecithin, tocopherols, tricalcium phosphate, xanthan gum, zinc oxide

Avoid dairy-based proteins

Dairy-based proteins like whey and casein can cause protein shake diarrhea because they contain lactose, a sugar most adults cannot fully digest.

Avoid artificial sweeteners and sugar alcohols

Artificial sweeteners and sugar alcohols also resist digestion and can therefore have a laxative effect. Common artificial sweeteners include sucralose and acesulfame potassium. Common sugar alcohols include erythritol, sorbitol, and xylitol. 

Limit insoluble fiber intake

Insoluble fiber adds bulk to the stool, so if you eat a lot of it at once, it can cause diarrhea. Most vegan protein supplements naturally contain insoluble fiber.

Some protein shakes and powders, especially those intended to help with weight loss, contain added insoluble fiber. These are what you really need to look out for as the added fiber they use is usually guar gum or inulin, which also happen to be used as laxatives! 

Be mindful of preexisting gut issues

When you eat dietary protein, it enters the stomach where stomach acid and enzymes start to break it down into smaller components. From there, the partially digested proteins move to the small intestine, where enzymes called proteases break them down into amino acids. Amino acids are then absorbed through the intestinal lining and enter the bloodstream, which transports them throughout the body.

If any part of this complex process is not working properly due to preexisting gut issues, then the protein you eat will not be fully broken down and absorbed. Not only will this deprive you of the amino acids you need to stay strong and healthy, but it can also cause painful side effects like diarrhea.


What should you do if you have protein shake diarrhea?

If you have diarrhea after drinking a protein shake, there are several steps you can take to manage it:

Stay hydrated

Diarrhea can lead to dehydration due to fluid loss. Drink plenty of clear fluids and avoid caffeinated and alcoholic beverages.

Eat bland foods

Stick to bland, easily digestible foods such as bananas and rice. These foods can help firm up stools without aggravating your stomach.


Give your body time to recover by getting plenty of rest. Avoid strenuous activities that can further deplete your energy levels.

Seek medical attention if necessary

If your diarrhea persists for more than a couple of days, you should consult a healthcare professional. They can help determine the underlying cause and provide appropriate treatment. Similarly, while managing protein shake diarrhea at home, it is essential to monitor your symptoms closely and seek medical advice if you are unsure about the best course of action.

Protein Powders

Collagen Protein Powder Starter Kit

Starting at $94.97

Protein Powders

Egg White Protein Powder Starter Kit

Starting at $94.97

Protein Powders

Vegan Almond Protein Powder Starter Kit

Starting at $94.97


drink wholesome does not cause diarrhea

Our protein powder does not cause diarrhea because we use a short list of simple ingredients free from food additives, dairy-based proteins, and protein concentrates and isolates. 

Our ingredients

egg whites

egg whites





monk fruit

monk fruit

NOT our ingredients

  • acacia gum

  • acesulfame potassium

  • artificial flavors

  • carrageenan

  • erythritol

  • guar gum

  • inulin

  • maltodextrin

  • 'natural' flavors

  • silica

  • soy lecithin

  • sucralose

  • xanthan gum

  • xylitol

Note that instead of using protein concentrates or isolates, we use whole food protein sources like collagen, egg whites, and almonds, which are easier to digest and absorb. Whole food protein sources also have unique digestive benefits: collagen can reduce bloating and improve digestive symptoms, egg whites can help restore your mucosal intestinal barrier, and almonds can improve the composition of your gut microbiome.

It follows that our customers experience fewer digestive issues with our protein powder than with any other type of protein supplement. Order samples to see for yourself. 



1 week ago

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For Egg White Protein Powder


2 weeks ago

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For Egg White Protein Powder


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Frequently asked questions

Collagen vs egg white vs almond protein powder?

You may have noticed that we make three types of protein powder: collagen protein powderegg white protein powder, and vegan almond protein powder. As long as you are eating a balanced diet, any type of protein powder can help you boost your protein intake. Just pick the type that best suits your dietary needs and personal preferences.

Protein powder vs meal replacement powder?

You may have noticed that we make protein powders and meal replacement powders. The difference between protein powders and meal replacement powders is the nutrition content. Protein powders are high in protein and low in everything else, whereas meal replacement powders contain fats, carbs, and protein because they are intended to replace the nutritional value of a healthy meal.

Learn more

My name is Jack and I created drink wholesome because I was sick of protein powders that upset my stomach. Read my story, check out my short list of simple ingredients, and browse reviews from other customers to learn more.



Protein Rice Krispies Treats


15 min


0 min




In a large pot, melt the butter over low heat. Add the marshmallows, and stir until the mixture is smooth. Remove the pot from the heat, and incorporate the protein powder. Add the Rice Krispies, stirring until combined. Transfer the mixture to a 9×13 inch greased pan. Let your Protein Rice Krispie Treats sit for 30 minutes before eating.


This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. drink wholesome is not intended to diagnose, treat, cure or prevent any disease.