What causes protein shake diarrhea? 

If you are sick of protein shake diarrhea, you have come to the right place. In the article below, I will explain what causes protein shake diarrhea, and how to avoid this common side effect.


Protein shake diarrhea has several causes.

Written by Jack Schrupp & endorsed by Baylee Reller, RDN

Can protein shakes cause diarrhea?

If you find yourself rushing to the bathroom after drinking a protein shake, rest assured, 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 powder that will not trigger diarrhea.

How to avoid protein shake diarrhea.

Choose a protein shake that is dairy-free.

Dairy-based proteins like whey and casein, which are byproducts of cheese and yogurt production, are notorious for causing diarrhea, especially among individuals with lactose intolerance. Lactose intolerance, which afflicts over one in three adults, stems from an inability to fully digest lactose, the sugar in dairy. When lactose is only partially digested, it acts as a magnet for water, drawing it into the colon due to its high osmotic load.

High osmotic load refers to a situation where the concentration of solutes (in this case, unabsorbed lactose) in a solution is high. With a high osmotic load, there is increased osmotic pressure, which is the force exerted by a solvent, typically water, as it moves through a semipermeable membrane (in this case, the colon) to balance the solute concentrations on both sides of the membrane. Essentially, unabsorbed lactose increases the liquid content of stool, leading to diarrhea.


Choose a protein supplement that is sugar alcohol-free.

A lot of protein powders are sweetened sugar alcohols, which are a type of carbohydrate that resists digestion. Similar to lactose, sugar alcohols have a laxative effect because they are not absorbed efficiently, and as a result, draw water into your colon. Some commonly used sugar alcohols you might encounter include erythritol, sorbitol, and xylitol.

Choose a protein supplement that is low in fiber.

Certain plant-based protein powders pack a hefty dose of fiber. Now, he is the thing about fiber: it is great for softening stool and making it move through the digestive system with ease because it soaks up water. But, as you might guess, an excess of fiber can actually lead to diarrhea. It is worth noting that some protein powders, especially those designed for weight loss, toss in extra fiber. As a general rule, if a serving clocks in at more than 10 grams of fiber, it is likely a bit too much.

Choose a protein supplement that is additive-free.

Most protein powders contain a cocktail of food additives, which look nothing like real food, and are therefore really hard to digest. For this reason, they pull water into the intestines, soften stool, speed up colonic transit, and cause diarrhea. 

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

acacia gum, acesulfame potassium, artificial flavors, aspartame, carrageenan, cellulose gum, dextrin, dextrose, erythritol, gellan gum, guar gum, gum arabic, inulin, locust bean gum, “natural” flavors, maltodextrin, rice syrup solids, soy lecithin, silica, sucralose, sunflower lecithin, xanthan gum


Why drink wholesome

Our protein powder does not cause diarrhea because it is dairy-free, sugar alcohol-free, low in fiber, and additive-free.

the alternative:

Protein Matrix Comprised of (Whey Protein Concentrate,  Whey Protein Isolate, Calcium Caseinate, Micellar Casein, Milk Protein Isolate, Egg Albumen, Glutamine Peptides), Polydextrose, Sunflower Creamer (Sunflower Oil, Corn Syrup Solids,  Sodium Caseinate, Mono- and Diglycerides, Dipotassium Phosphate, Tricalcium Phosphate, Soy Lecithin, Tocopherols), Natural and Artificial Flavor, MCT Powder (Medium Chain Triglycerides, Nonfat Dry Milk, Disodium Phosphate, Silicon Dioxide), Lecithin, Cellulose Gum, Salt, Yellow 5, Sucralose, Acesulfame Potassium, Papain, Bromelain

Moreover, unlike nearly every other protein supplement, drink wholesome is made with real foods, not protein isolates or concentrates. Protein isolates and concentrates are foods stripped of everything but the protein. They undergo extensive mechanical and chemical processing, and in many cases, chemical solvents like hexane are used to extract the protein. This means that what you put into your protein shake looks nothing like real food.

vanilla protein powder 28 servings lifestyle image 1
vegan vanilla protein powder lifestyle image 2

Your gut is meant to digest unprocessed or minimally-processed real foods, not protein concentrates or isolates. This is why more and more research is finding that regularly eating processed ingredients like these can alter the composition of your gut microbiome – the collection of microorganisms living in your gut. Your gut microbiome helps you digest food, and alterations to its composition can make it harder for you to break down and absorb what you eat. This, as you now know, can cause side effects like diarrhea.

vegan chocolate protein powder lifestyle image 1
chocolate protein powder 28 servings lifestyle image 2


easy to digest

“Thank you thank you thank you. This tastes great, mixes well, and does not make me run to the bathroom like most protein powders. I will be ordering again!” – Henry

Read more reviews or take the quiz.


vegan chocolate protein powder

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3 protein powder samples


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.


The Protein Shake Diarrhea Dilemma: Exploring Causes and Solutions


Protein shakes have become a popular dietary supplement for athletes, fitness enthusiasts, and those looking to boost their protein intake. However, many individuals have reported experiencing an unpleasant side effect known as “protein shake diarrhea.” In this comprehensive blog post, we will delve deep into the causes of protein shake diarrhea, its variations, and why some protein sources like egg white protein powder and almond protein powder are less likely to cause this issue.

Understanding Protein Shake Diarrhea

Protein shake diarrhea, also known as “protein-induced diarrhea,” is a common problem that some individuals encounter after consuming protein shakes. It is characterized by loose or watery stools, cramping, and an urgent need to visit the bathroom shortly after consuming a protein shake. While it may not affect everyone, it can be an uncomfortable and embarrassing experience for those who do.

Common Causes of Protein Shake Diarrhea

  1. Lactose Intolerance: Many commercial protein shakes contain whey protein, a dairy-derived protein source. Individuals with lactose intolerance lack the enzyme needed to digest lactose, the sugar found in dairy products. Consuming whey-based protein shakes can lead to gastrointestinal discomfort, including diarrhea, in these individuals.
  2. Artificial Sweeteners: Some protein shakes are sweetened with artificial sweeteners like sorbitol, mannitol, or sucralose. These sweeteners can have a laxative effect on some people, leading to diarrhea and digestive upset.
  3. High Fiber Content: Some protein shakes contain added fiber, which can be beneficial for digestion in moderate amounts. However, excessive fiber intake, especially in the form of insoluble fiber, can lead to diarrhea as it passes through the digestive tract quickly.
  4. Poorly Tolerated Protein Sources: Some protein sources used in shakes may not be well-tolerated by certain individuals. This can include specific plant-based proteins or low-quality protein powders that may contain impurities or allergens.

Why Egg White Protein Powder Doesn’t Cause Protein Shake Diarrhea

Egg white protein powder is a protein supplement made from the whites of eggs. It is known for its high protein content and bioavailability, making it a popular choice among fitness enthusiasts. Here are some reasons why egg white protein powder is less likely to cause protein shake diarrhea:

  1. Lactose-Free: Egg white protein powder is naturally lactose-free, making it suitable for individuals with lactose intolerance.
  2. High Digestibility: Egg white protein is highly digestible and typically gentle on the stomach, reducing the likelihood of digestive discomfort and diarrhea.
  3. Minimal Additives: High-quality egg white protein powders often contain minimal additives, reducing the risk of ingesting artificial sweeteners or excess fiber that could trigger diarrhea.

Why Almond Protein Powder Doesn’t Cause Protein Shake Diarrhea

Almond protein powder is another plant-based protein source that is less likely to cause protein shake diarrhea when compared to some other plant-based options. Here’s why almond protein powder is a better choice for individuals prone to digestive issues:

  1. Low in FODMAPs: Almond protein powder is low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs), which can trigger digestive symptoms, including diarrhea, in some people.
  2. Nutrient-Rich: Almonds are naturally rich in fiber, healthy fats, and vitamins, making almond protein powder a more balanced and nutritious choice.
  3. Allergen-Friendly: Almond protein is less likely to cause allergic reactions compared to some other plant-based protein sources like soy or pea protein.

How to Prevent Protein Shake Diarrhea

If you’ve experienced protein shake diarrhea or want to avoid it altogether, here are some strategies to consider:

  1. Choose the Right Protein Powder: Opt for high-quality protein powders that are free from artificial sweeteners, excessive fiber, and allergens. Consider lactose-free options like egg white protein or almond protein powders.
  2. Gradual Intake: If you’re new to protein shakes, start with a smaller serving size and gradually increase it to allow your digestive system to adapt.
  3. Stay Hydrated: Ensure you’re drinking enough water throughout the day, as insufficient hydration can exacerbate digestive issues.
  4. Monitor Fiber Intake: Be mindful of the fiber content in your protein shakes. Excessive fiber intake can lead to diarrhea, so choose products with a moderate fiber content.
  5. Track Ingredient Tolerance: Keep a food diary to identify specific ingredients or additives that trigger digestive discomfort, and avoid products containing them.
  6. Consider Digestive Enzymes: Some individuals find relief from protein shake-related digestive issues by taking digestive enzyme supplements with their shakes to aid in protein digestion.


Protein shake diarrhea is a common issue that can be uncomfortable and inconvenient for those who experience it. However, by choosing the right protein sources and being mindful of additives and fiber content, you can minimize the risk of this problem. Egg white protein powder and almond protein powder are two excellent options for individuals seeking protein supplementation without the associated digestive discomfort. Remember to consult with a healthcare professional if you continue to experience severe or persistent digestive issues after consuming protein shakes.