Is whey protein powder bad for you?

Written by Jack Schrupp and reviewed by Ella McGonagle, M.S. Nutrition

Is whey protein powder bad for you? Whey protein is not a healthy choice for many people. Keep reading to learn more about whey, how it is made, and possible side effects.

“If you have a sensitive gut, you need simple ingredients.”

-Brittany Carpenter, MS, RDN/LDN

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2 reasons why whey protein powder is bad for you.

Whey protein can cause acne.

Whey protein can upset your stomach. 

Why drink wholesome?

Whey protein can cause acne.


Dairy-based proteins like whey and casein can cause acne. Dairy indirectly stimulates insulin production, which regulates sebum production. Sebum, an oily, waxy substance produced by your body’s sebaceous glands, can clog your pores and cause pimples. Dairy can also hinder your ability to process blood sugar efficiently, which can cause inflammation in your skin. Clinical evidence shows that inflammation occurs at all stages of acne development.

Whey protein can upset your stomach. 


Dairy-based proteins are also known to cause digestive issues, especially for people with lactose intolerance and irritable bowel syndrome (IBS). Over one in three Americans are lactose intolerant, and the prevalence of IBS is somewhere between 10 and 15 percent in the United States. It follows that you may be lactose intolerant or have IBS and not even know it. Irritable bowel syndrome (IBS) is a poorly understood condition, and it is unclear why dairy triggers symptoms.

Lactose intolerance, on the other hand, is clearly understood. People with lactose intolerance are unable to fully digest lactose, the sugar in dairy. Partially digested food sits in your gut for longer than food should, which gives your gut bacteria more time to eat. As they eat, these bacteria produce gas, which causes bloating and stomach pain. Gas also slows colonic transit (the amount of time it takes food to travel through the colon), and can lead to constipation. 

Most whey protein powders are made with protein concentrates and/or isolates, foods stripped of everything but the protein. They are listed on the ingredient list as “pea protein” and “whey protein” as opposed to “peas” and “whey.” I will not go into the details, but protein concentrates and isolates undergo heavy mechanical and chemical processing before becoming protein powder. Sometimes, manufacturers use chemical solvents like hexane to isolate (separate) the protein from the food. This means that what you end up putting into your body looks nothing like real food.

If you think about it, your gut was designed to digest naturally occurring foods, not laboratory formulated imitations, so if you feed it anything but real food, it might get upset. The long term implications of eating processed foods are still not well understood, but more and more research is finding that it can alter the composition of your gut microbiota, and lead to permanent damage to the gut microbiome. Keep reading to learn more about why whey protein causes digestive distress.

Why does whey protein cause gas?

As you just learned, some people, especially those with lactose intolerance and irritable bowel syndrome (IBS), can only partially digest whey protein. Whey protein therefore feeds the bacteria in their gut for longer than it should, which produces excessive gas.

Why does whey protein make me bloated?

Bloating occurs when the gastrointestinal (GI) tract is filled with gas. Because whey protein can cause gas, it can also cause bloating.

Why does whey protein hurt my stomach?

Stomach pain is often a symptom of bloating. Since whey protein can cause bloating, it can also cause stomach pain.

Why does whey protein make me sick?

Side effects like excessive gas and bloating are often accompanied by nausea, the feeling of discomfort that makes you feel as though you might vomit. Since whey protein can cause excessive gas and bloating, it can also make you feel sick. 

Why does whey protein make me poop?

Partially digested whey protein sometimes passes through the colon more quickly than it should, which can cause diarrhea. 

When buying protein powder for sensitive stomachs, one ingredient to avoid in particular is artificial sweeteners. Artificial sweeteners are among the most harmful food additives in the long term as they alter the composition of your gut microbiota (the collection of microorganisms that help you digest food). This can lead to serious, chronic GI problems, widespread inflammation, and permanent damage to the gut microbiome. Some sweeteners, especially sugar alcohols like xylitol, are also poorly absorbed by the gut (meaning they feed those hungry gut bacteria), and cause diarrhea because they draw water into your intestine. Now you finally have something to blame for those post-protein shake trips to the bathroom!

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, xylitol

When it comes to identifying food additives, go with your gut. 😉 As a rule of thumb, they are the ingredients that you cannot pronounce. Food additives are not the only thing to look out for when buying protein powder for sensitive stomachs, however. There are several other ingredients that can upset your stomach.

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.

*This is the actual ingredient list of one of the best-selling whey protein powders in the United States.

We make the best whey protein alternatives with egg whites and almonds. Egg whites are simply pasteurized and dried before becoming protein powder. Almonds are just roasted, pressed, and ground. Minimally-processed ingredients like these are an easy to digest, gut-friendly alternative to dairy-based protein concentrates and isolates. Unless you have a sensitivity or allergy to eggs, egg white protein is the best protein for your gut. Egg whites are low in fiber, low-FODMAP, naturally alkaline, and have the highest protein digestibility-corrected amino acid score (PDCAAS) of any whole food. Our customers have experienced fewer digestive issues with egg white protein than with any other type of protein. If you cannot eat eggs, try our almond protein powder. Unlike protein concentrates or isolates, almonds contain lots of healthy fats, fiber, and other nutrients like calcium and vitamin E. We prefer almonds to other minimally-processed plant protein sources because they are more gut-friendly. Research suggests that almonds possess prebiotic properties and can improve the diversity and composition of the gut microbiome.

★★★★★

easy to digest

“I’ve had Crohn’s disease for 20+ years and it’s always been hard to find a protein powder my stomach can handle. I’ve had no problem digesting drink wholesome AND it tastes great. I highly recommend this protein powder if you have IBS or Crohn’s.” – Jesse

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Whey protein powder is bad for you.

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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.

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