Can Protein Powder Cause Constipation?

📌 Overview and Key Takeaways

Protein powder can cause constipation.

Discover what causes protein powder constipation and how to avoid this common side effect.

Last Updated
Jul 21, 2026

Author and Medical Reviewer

Written by Jack, CNC

Jack is a National Academy of Sports Medicine Certified Nutrition Coach.

Disclaimer: This communication is for general informational purposes only and is not a substitute for personalized medical advice. Consult a licensed healthcare professional before making changes to your diet.

Protein Powder Constipation

Does Protein Powder Cause Constipation?

Yes, protein powder can cause constipation.

While many people experience diarrhea from protein shakes and powders, others find that protein shakes and powders make them constipated.

Constipation means having fewer than three bowel movements per week with stools that are hard and difficult to pass.

Common symptoms include bloating, nausea, and stomach pain.

While constipation usually resolves on its own, you should always talk to a healthcare professional if your symptoms persist.

Why Does Protein Powder Cause Constipation?

Protein powder constipation is rarely caused by the protein itself.

Protein powders typically lead to constipation because they contain added ingredients that are hard to digest.

Here are the protein powder ingredients that can make you constipated:

Food Additives

Emulsifiers, thickeners, and other ultra-processed additives look nothing like real food, making them hard to digest.

They therefore feed your gut bacteria, which produce gas as they eat.

Excess intestinal gas can cause bloating and constipation.

Eating certain food additives regularly can also change the makeup and function of your gut microbiome – the community of bacteria and other microorganisms living in your digestive tract (North Clin Istanb, 2020).

These shifts, called gut dysbiosis, contribute to constipation through several mechanisms (Appl Microbiol Biotechnol, 2022).

For example, gut dysbiosis disrupts the production of key compounds like short-chain fatty acids, bile acids, and tryptophan metabolites, which help regulate intestinal movement and fluid secretion.

⚠️ Here is a list of the most common food additives in protein shakes and powders:

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

As a rule of thumb, if you cannot find it in nature or make it at home, it is probably a food additive.

🚫 Avoid Dairy-Based Proteins

Dairy-based proteins like whey and casein, although not a problem for everyone, can cause digestive issues too.

This is usually because they contain lactose – a sugar many individuals with sensitive stomachs cannot fully digest.

But you might be sensitive to dairy-based proteins even if you are not lactose intolerant.

For starters, the digestion of some caseins releases a bioactive peptide that has been linked to digestive issues (Adv Nutr, 2017).

Casein also forms a gel-like substance in your stomach that slows down digestion (Crit Rev Food Sci Nutr, 2023).

For sensitive individuals, particularly true for those with cow’s milk protein allergy or intolerance, slower digestion can contribute to bloating, constipation, and other side effects.

🚫 Avoid Protein Concentrates and Isolates

If you have a sensitive stomach, you might also want to avoid protein concentrates and isolates.

Most protein shakes and powders are made from one or both of these ultra-processed protein sources, which have been mechanically and/or chemically stripped of everything but the protein.

This includes the enzymes, fiber, and other natural digestive aids that help you break them down.

You therefore do not digest them in the same way that you do whole foods, which could affect your gut health.

For example, one study shows that regularly consuming protein concentrates and isolates might disrupt your gut microbiome (Nutrients, 2018).

Another study shows that it could cause the formation of toxic byproducts in your gut (Mol Nutr Food Res, 2024).

Although further research is needed, individuals with sensitive stomachs can play it safe by choosing protein shakes and powders made from minimally-processed protein sources like egg whites and almonds.

They are more gut-friendly.

Order Samples to see for yourself.

What Should I Do if Protein Powder Makes Me Constipated?

If you are constipated and need relief, try these remedies:

1. Drink water. Drinking lots of water softens your stools. Try warm or hot water in the morning.
2. Exercise. Movement stimulates the muscles in your colon.
3. Eat fiber. Fiber increases stool size and helps it move through your digestive tract. It also softens stool, making it easier to pass.
4. Drink coffee. Caffeine stimulates muscle contractions in your colon.
5. Use a laxative. If nothing else works, try an over-the-counter laxative. Laxatives can have side effects like allergic reactions, vitamin deficiencies, and dehydration, so use them as a last resort.

Remember that everyone is different, so what works for someone else might not work for you.

Be patient too – most remedies take 12 to 72 hours to work.

Finally, it is important to note that occasional constipation is normal.

If protein powders regularly make you constipated, however, then it might be time to switch brands.

If you do, start with a smaller serving size to see how your body responds.

Then, gradually increase the serving size over time as your tolerance allows.

Sources

1. Northern Clinics of Istanbul (North Clin Istanb). Food additives and microbiota. 2020.
2. Applied Microbiology and Biotechnology (Appl Microbiol Biotechnol). Gut microbiota: a new avenue to reveal pathological mechanisms of constipation. 2022.
3. Advances in Nutrition | Journal (Adv Nutr). Systematic Review of the Gastrointestinal Effects of A1 Compared with A2 β-Casein. 2017.
4. Critical Reviews in Food Science and Nutrition (Crit Rev Food Sci Nutr). Milk proteins: Processing, gastric coagulation, amino acid availability and muscle protein synthesis. 2023.
5. Nutrients (Nutrients). Effect of a Protein Supplement on the Gut Microbiota of Endurance Athletes: A Randomized, Controlled, Double-Blind Pilot Study. 2018.
6. Molecular Nutrition & Food Research (Mol Nutr Food Res). In Vitro Fermentation of Animal and Plant Protein Isolates by the Human Gut Microbiota Under High and Low Carbohydrate Conditions. 2024.

Editorial Guidelines

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This article was written by a Certified Nutrition Coach and reviewed by a Registered Dietitian. We rely on peer-reviewed research and trusted medical sources, and regularly update our content to ensure accuracy and clarity.