How to Find the Best Protein Powder for Lactose Intolerance

📌 Overview and Key Takeaways

This is a Dietitian’s guide on how to find the best protein powder for lactose intolerance.

Discover how to safely supplement your protein intake without lactose.

Last Updated
Jan 8, 2026

Author and Medical Reviewer

Written by Kayla Kamen, MS, RD

Kayla Kamen is a Registered Dietitian with a MS in Nutrition.

Medically reviewed by Jennifer Fossett, PA-C

Jennifer Fossett is a Physician Assistant with a BA in Nutritional Sciences.

Protein Powder for Lactose Intolerance

Which Protein Powders Are Lactose-Free?

Lactose is a sugar in milk and dairy products such as yogurt, ice cream, and whey protein.

It is created when two other sugars, glucose and galactose, combine.

To digest lactose, you need an enzyme called lactase; lactose intolerance happens when your body does not produce enough of this enzyme.

About two-thirds of the world’s population suffers from some degree of lactose intolerance.

It is so common because humans no longer “need” to digest milk after breastfeeding, so they begin to produce less lactase.

If you are lactose intolerant, you might experience bloating, diarrhea, and other side effects after consuming dairy.

If something is lactose-free, it has no lactose in it.

Lactose-free does not necessarily mean dairy-free, however.

This distinction is important to understand, especially if you have a dairy allergy.

On the flip side, dairy-free always means lactose-free.

Cow’s milk-based proteins like whey and casein, which are byproducts of cheese and yogurt production, contain lactose.

If you are lactose intolerant, avoid protein powders made from whey and casein.

If you have severe lactose intolerance, you should avoid goat’s milk-based protein too.

Goat’s milk contains less lactose than cow’s milk, but it can still upset your stomach.

It is important to note that dairy-based food additives like sodium caseinate contain small amounts of lactose.

To be safe, people with severe lactose intolerance should therefore use a protein powder that is dairy-free.

What Is the Best Protein Powder for Lactose Intolerant People?

There are several types of lactose-free protein powder.

Some of the most common include egg white, beef, and plant-based protein powders.

Some people will tell you that plant-based protein powders are inferior to whey because they are not “complete” proteins, which is misleading.

Whey protein is a complete protein, meaning it contains all of the essential amino acids, but 99% of people easily meet 100% of their essential amino acid needs without protein supplements (J Nutr, 2023).

And excess amino acids are either excreted as waste, used for energy, or stored as fat.

In other words, most people do not benefit from the superior amino acid profile of whey protein.

This is why research shows that supplementing your dietary protein intake with plant-based proteins is just as effective as supplementing with whey, or any other animal-based protein (J Int Soc Sports Nutr, 2015).

As long as you are eating a balanced diet – getting your dietary protein from a variety sources – the type of protein powder you use does not matter.

Ingredients do matter, however, especially if you have a sensitive stomach.

For example, many lactose-free protein powders contain ingredients that might cause painful side effects and even long-term digestive issues.

Among the top offenders are ultra-processed food additives and protein concentrates and isolates.

🚫 Avoid Food Additives

Regularly eating emulsifiers, thickeners, artificial sweeteners, and other ultra-processed additives can alter the composition and function of your gut microbiome (North Clin Istanb, 2019).

These shifts, known as gut dysbiosis, have been linked to the development of chronic digestive issues like IBS (JGH Open, 2021).

Dysbiosis can disrupt intestinal barrier function, modulate immune responses, and affect gut motility, all of which contribute to digestive symptoms.

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

• 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 an issue for everyone, can cause digestive issues.

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.

This is particularly true for casein protein, which forms a gel-like substance in your stomach that slows down digestion.

🚫 Avoid Protein Concentrates and Isolates

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

Most protein supplements 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 your gut break them down.

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

Studies show that regularly eating protein concentrates and isolates might disrupt your gut microbiome (Nutrients, 2018) and cause the formation of toxic byproducts in your gut (Mol Nutr Food Res, 2024).

Individuals with pre-existing digestive issues should thus look for protein supplements made from whole food protein sources like egg whites and almonds, which are easier to digest and absorb.

Order Samples to see for yourself.

Sources

1. The Journal of nutrition (J Nutr). Amino Acid Intake and Conformance With the Dietary Reference Intakes in the United States: Analysis of the National Health and Nutrition Examination Survey, 2001-2018. 2023.
2. Journal of the International Society of Sports Nutrition (J Int Soc Sports Nutr). Pea proteins oral supplementation promotes muscle thickness gains during resistance training: a double-blind, randomized, Placebo-controlled clinical trial vs. Whey protein. 2015.
3. Northern Clinics of Istanbul (North Clin Istanb). Food additives and microbiota. 2019.
4. JGH Open: An Open Access Journal of Gastroenterology and Hepatology (JGH Open). Gut microbiota dysbiosis in functional gastrointestinal disorders: Underpinning the symptoms and pathophysiology. 2021.
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 Registered Dietitian and reviewed by a Physician Assistant. We rely on peer-reviewed research and trusted medical sources, and regularly update our content to ensure accuracy and clarity.