Can Protein Shakes Cause Constipation? – A Review of Protein Shakes and Constipation

how protein shakes can impact your digestive system

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Hello, thank you for visiting my website! Please note, I am not a doctor, and I do not provide medical advice. However, I am a Certified Personal Trainer, a Professional Basketball Player, and I am currently completing my Masters Degree in Nutrition Education from American University. Also, this website contains affiliate links. Please read my Medical Disclaimer and Review Disclaimer for more information.

Many people wonder, “do protein shakes cause constipation,” since there are so many reports of people having upset stomachs or other stomach issues after drinking protein shakes. Protein shakes can cause constipation due to some of their ingredients, but protein shakes as a whole definitely don’t cause constipation you just have to find one with the right ingredients!

Constipation is a common digestive problem and affects many people, and it can occur for many different reasons. According to The Cleveland Clinic, common causes of constipation are,

  • Eating foods low in fiber
  • Not drinking enough water (dehydration)
  • Not getting enough exercise
  • Changes in your regular routine, such as traveling or eating or going to bed at different times.

As you can see, there are a lot of causes of constipation, so having to deal with it because of your protein shakes is the last thing you want because you can easily avoid this issue.

Keep reading below to learn more about what ingredients in protein shakes cause constipation, and the best alternatives!

Why Do Protein Shakes Cause Constipation?

Generally speaking, protein shakes themselves don’t cause constipation, but many of them contain the ingredients that can lead to it. The common ingredients in protein drinks that cause constipation include:

Lactose and Casein

If you drink whey protein powder or casein protein, you might be causing constipation or other stomach issues for yourself.

Most people are intolerant to lactose in one way or another, and constipation often results from lactose intake. Yet, many protein shakes use casein and whey protein concentrates as their sources of protein, which are difficult for the stomach to digest.

One of the “benefits” of casein protein powders is that they take a long time to digest, and provide your body with protein for an extended period. This is great if your stomach can handle it, but it’s bad if it cannot.

Both casein and whey protein supplements usually retain considerable amounts of lactose, and may expose you to the adverse effects of consuming it.

If you have stomach issues, avoiding lactose and casein protein is a good idea!


Soy is another contributor to constipation that is often overlooked. Frequently included in protein shakes as a non-dairy form of protein, soy is a phytoestrogen that can slow down digestion. According to a study published in Gastroenterology,

“Slow transit chronic constipation in women may be caused by down-regulation of contractile G proteins and up-regulation of inhibitory G proteins, probably caused by overexpression of progesterone receptors.”

The slower the work of the digestive tract gets, the more difficult stools become for the bowel to pass efficiently.


Many protein shakes available on the market today contain considerable amounts of sodium. In excessive amounts, sodium causes body wide retention of fluids, depriving the digestive tract of fluids to perform its functions.

As a result, the digestive tract takes missing fluids out of stools, causing them to harden and leading to constipation.


Serving as a source of carbohydrates for bodybuilders or athletes, oats and dextrins are a mainstay of many protein shakes. Both, however, they are prone to contamination by gluten during the manufacturing process. Since gluten is a known allergen that disrupts the work of the entire gastrointestinal tract, it can easily cause constipation.


Artificial sweeteners and sugar alcohols is what gives so many protein shakes on the market rich flavors. Sadly, these compounds are capable of undermining the health of the entire gut flora over time. As a result, popular sweeteners like sucralose and sugar alcohols like sorbitol are often direct contributors to constipation.

Alternatives to Protein Shakes that Cause Constipation

If your protein shake or protein supplement is causing you digestive system issues such as constipation, switching to a vegan protein powder such as Your Super Muscle Power can usually make a huge difference!

Your Super Muscle Power is a great option because it contains pea protein, which can actually stimulate your digestion instead of causing constipation. This is the protein powder I use, and I am confident you will enjoy it as well.

Your Super Muscle Power Superfood Mix - Plant Based Protein Powder, Workout Boost with All 9 Essential Amino-Acids, Whey Alternative, Non-GMO, Organic Maca, Lucuma - 14.1 Ounces, 26 Servings
101 Reviews
Your Super Muscle Power Superfood Mix - Plant Based Protein Powder, Workout Boost with All 9 Essential Amino-Acids, Whey Alternative, Non-GMO, Organic Maca, Lucuma - 14.1 Ounces, 26 Servings
  • PLANT PROTEIN FOR ENERGY: The perfect combination of plant protein and energizing superfoods. This...
  • CONTAINS 9 ESSENTIAL AMINO ACIDS: Including Vitamin C, B6, Iron, Niacin and Copper.
  • POWERFUL ORGANIC INGREDIENTS: Naturally dried ingredients to preserve all micronutrients; tested by...
  • NO SWEETENERS OR FILLERS EVER: No stevia, thickeners or artificial flavoring – Made with 5 energy...
  • EASY TO USE: Simply add two tablespoons of the mix to smoothies, water, breakfast, snacks or...

Concluding Thouhts – Are Your Protein Shakes Causing Constipation?

If your meal replacement supplement or protein shakes doesn’t seem to contain the above ingredients, you need to address other factors. Not eating enough fiber and foods rich in probiotics, dehydration, and lack of movement are all popular causes of constipation.

Often, maintaining control over these subtle causes of constipation can be enough to prevent this digestive problem from occurring, and allow you to enjoy your protein shakes without ever having to go through the trouble of experiencing it.

Read Next: Visalus Shake Recipes with Almond Milk


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