5 Protein Powders That DON’T Cause Bloating (Expert Tested)

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A common concern when purchasing protein powder is whether it will cause side effects like gassiness, bloating, or constipation. 

The good news is that the quality of whey protein powders has improved significantly over the past few years. They are much more digestible and have fewer side effects than past products. 

I’ve been a supplement store manager and nutrition coach for over a decade, allowing me to test dozens of brands and products in my career. I also have a dairy sensitivity, which makes me especially susceptible to side effects from protein powder. 

Based on my experience, I’ll cover the best protein powders that DON’T cause bloating. 

In a Hurry? Here’s My Top Pick: 

Transparent Labs Whey Isolate is my #1 pick for a protein that doesn’t cause bloating.  It’s a naturally flavored protein that doesn’t use artificial sweeteners, colors, or preservatives. Transparent Labs also has a 100% money-back guarantee, so if the protein doesn’t digest well, you can get a full refund.

At A Glance

Best Overall

Transparent Lab Whey Protein Isolate

Transparent Labs Grass-Fed Whey Isolate

  • Grass-fed Whey Isolate
  • 28g of protein per scoop
  • Third party tested with publicly disclosed results
  • Available in 15 Flavor
  • Gluten Free
  • No Artificial flavors or colors

Best Unflavored

BulkSupplements.com Whey Isolate

  • Whey Isolate Protein
  • 26g protein per scoop
  • Unflavored
  • Only 2 ingredients
  • Third Party Tested

Best Plant-Based

Vega Sport

  • Blend of pea, pumpkin seed, brown rice, and alfalfa protein
  • 30g protein per scoop
  • Has added probiotics to support digestion
  • Third party tested and Non-GMO Project Verified

RANKED: Protein Powders That Don’t Cause Bloating

Best Overall: Transparent Labs Grass-Fed Whey Isolate

Check out our video review of Transparent Labs Protein Powder

Overall rating: 

  • 4.75/5

Key Features:

  • Price: $$ ($1.75-$2.00 per serving)
  • Calories: 120
  • Protein Content: 28g (93% calories from protein)
  • Sugar: 0-1g 
  • Protein Source: Grass-fed whey isolate
  • Potentially Constipating Ingredients: Whey (dairy), Stevia
  • Likelihood to cause constipation on a scale of 1(low) to 5(extreme): 1

Our Thoughts:

Transparent Labs Grass-Fed Whey takes the top spot for individuals looking for a great-tasting protein powder that can be mixed with just water and doesn’t cause bloating. 

Transparent Labs adheres to some of the strictest quality and testing standards in the industry and offers 28g of protein per scoop, which makes up approximately 93% of its calories. 

With more than 14 flavors to choose from, Transparent Labs uses only natural flavors and stevia to sweeten their products. It contains no artificial sweeteners, colors, or gluten. 

While stevia can potentially cause digestive upset for some individuals, artificial sweeteners like sucralose and acesulfame potassium have been shown to be more disruptive to the gut and could be worse for causing constipation. 

Therefore, stevia is a safer bet than how most protein powders are sweetened. 

Most flavors have 0g of sugar and, as such, can be assumed to be lactose-free and safe for people with lactose intolerance.  I am lactose intolerant, and this is a protein powder I use daily, sometimes several times per day, with no issues. 

When comparing Transparent Labs Grass-Fed Whey Isolate to the average market cost of protein powder, it appears to be a more expensive option with a cost of $1.73 to $2.00 per serving compared to the average of $1.34. 

What’s important to note, though, is that the $1.34 average is established looking at the entire spectrum of protein powders on the market, from the lowest quality to the highest. 

To prevent constipation from your protein powder, you’ll need to look for a higher quality whey isolate or non-dairy protein that uses natural flavors and has the fewest additives possible.

When comparing Transparent Labs Isolate to other protein powders in that category, Transparent Labs is actually one of the most affordable options (as you’ll see later on this list).

If you believe stevia causes constipation for you, Transparent Labs does offer an unflavored option that skips the sweetener. 

If you are leaning this way, however, I suggest trying our second option below, BulkSupplements.com Whey Isolate, which has similar quality standards but at a lower cost per serving for the unflavored version. 

Finally, if you do end up buying Transparent Labs, and you get bloated, you can return the product and get a full refund. They have a 100% money-back guarantee!

Check out my complete review of Transparent Labs Whey Protein


  • High quality ingredients with no additives
  • Great taste with lots of variety
  • Great mixability
  • 0g of sugar makes this a suitable option for individuals with a lactose sensitivity


  • As a flavored dairy protein, it may still cause constipation in a small percentage of individuals 

Best Unflavored: Bulk Supplements Whey Isolate

Check out our video review of Bulk Supplements Whey Isolate

Overall rating: 

  • 4.6/5

Key Features:

  • Price: $ ($1.15-$1.45 per serving)
  • Calories: 110
  • Protein: 26g (94.5% calories from protein)
  • Sugar: 0g 
  • Protein Source: Whey Protein Isolate
  • Potentially Constipating Ingredients: Whey (dairy)
  • Likelihood to cause constipation on a scale of 1(low) to 5(extreme): 1

Our Thoughts:

BulkSupplements.com whey isolate is a colorless and flavorless whey protein isolate.

It has one of the highest protein percentages in the industry, with protein making up 94.5% of the product’s total calories. 

BulkSupplements.com Whey Isolate has 0g of sugar, making it virtually lactose-free. As such, it should be non-reactive in lactose-intolerant individuals. 

As an unflavored protein, it mixes easily into oatmeal or smoothies, where you can integrate extra fiber and fluids. This should eliminate any potential constipating side effects from this product. 

This is not the ideal protein powder for anybody looking for something they can just mix with water. Even though the product is “unflavored,” this doesn’t mean it’s tasteless. When mixed with just water, the product will have an undesirable taste. 

Aside from protein, the only ingredient is some sunflower lecithin to help the protein powder dissolve. The lack of additional ingredients or cheap fillers further reduces the likelihood that this protein powder will cause constipation.

Overall, BulkSupplements.com offers a great and inexpensive option (as low as $1.15 per serving) for anybody looking for a clean, high-quality whey protein powder.

Check out my complete review of BulkSupplements Whey Protein


  • Third-party tested with certificates of analysis available
  • No sugar (lactose)
  • No flavors, colors, sweeteners, or preservatives
  • It can be easily mixed into any recipe or smoothie
  • Inexpensive ($1.15-$1.45 per serving)


  • Doesn’t taste good just mixed with water
  • Doesn’t come with a scoop (you have to measure 4 tbsp to get 30g of protein)

Best Plant-Based: Vega Sport Premium Protein

Overall rating: 

  • 4/5

Key Features:

  • Price: $$$ ($2.22-$3.24 per serving)
  • Calories: 170
  • Protein Content: 30g (71% calories from protein)
  • Sugar: 1g
  • Protein Source: Pea protein, pumpkin seed protein, organic sunflower seed protein, alfalfa protein
  • Potentially Constipating Ingredients: Stevia
  • Likelihood to cause constipation on a scale of 1(low) to 5(extreme): 1

Our Thoughts:

Vega Sport is a vegan protein powder, which means it is completely dairy-free. It is the best option for anybody who suspects they have a dairy allergy or lactose sensitivity. 

It contains a massive 30g of protein powder per scoop, with protein making up approximately 71% of its total calories. While this is considered low for most whey protein powders standards, this is one of the highest protein percents of calories for a plant-based protein. 

The blend of plant-based ingredients provides 2-3g of fiber per serving. Fiber can be an important factor in preventing or alleviating constipation. Most protein powders contain no fiber at all, giving Vega Sport one more advantage over other options for people looking to prevent constipation.

Vegan protein powders have a more gritty texture and require more effort to help them dissolve. 

They also have a slightly more “natural” or “earthy” taste than whey proteins. 

For individuals who have experienced constipation from protein powders, though, the taste and texture are a welcome sacrifice to avoid those uncomfortable side effects. 

You can mix Vega Sport into a milk substitute like almond milk or blend it in a smoothie to provide a creamier texture and better flavor. You can also add it to recipes like oatmeal for added daily fiber.

Vega Sport is third-party tested, Non-GMO Project Verified, and Informed Choice certified. This means that the products and facilities undergo regular testing to ensure that they are free of banned substances and safe for elite athletes.

However, it does come with a premium price tag, ranging from $2.22 to $3.24 per serving, depending on which size tub you buy. This makes it the most expensive option on this list, but it is also the product least likely to cause constipation.


  • A blend of 4 plant-based proteins
  • 30g of protein per scoop
  • 3-4g of fiber per serving
  • NSF Certified, meaning each batch undergoes strict quality testing
  • The protein on this list that is least likely to cause constipation


  • Expensive ($2.22-$3.24 per serving)
  • Has a grittier texture and taste compared to whey protein

Best Beef Isolate: ATP Supreme Beef

ATP Supreme Beef

Overall rating:

  • 4/5 

Key Features:

  • Price: $$$ ($2.39 per serving)
  • Calories: 110
  • Protein Content: 24g (87% calories from protein)
  • Sugar: 0.1g
  • Protein Source: Grass fed Bovine Collagen Hydrolysate, Beef Bone Broth Protein
  • Potentially Constipating Ingredients: Stevia
  • Likelihood to cause constipation on a scale of 1(low) to 5(extreme): 1

Our Thoughts:

Feastgood.com hasn’t done an official in-depth review of ATP Supreme Beef Protein, but it’s the top-selling dairy-free protein powder in my store, and I’ve sampled a bottle previously. 

ATP Supreme Beef Protein uses a blend of beef collagen and beef bone broth protein to deliver a product that is dairy free and certified Gluten-Free. 

This makes it a perfect option for people who can’t have dairy or lactose, but don’t want the grittiness of earthiness that comes with a vegan protein powder. 

This high-quality beef protein is paleo friendly and uses only natural and organic sweeteners. These ingredients combine to create a product that is unlikely to cause constipation or digestive upset. 

ATP Supreme Beef is the second most expensive protein powder on this list, costing around $2.39 per serving. Similar to Vega Sport mentioned above, the high cost can be justified for individuals who can’t have or don’t want any dairy in their diets and want the highest-quality products. 

ATP’s beef protein is available in chocolate and vanilla. The vanilla is versatile and mixes easily into smoothies, water, oatmeal, and other recipes. The chocolate is a decadent rich cocoa flavor that tastes great just mixed with water, and also lends itself well to baking and oatmeal.


  • Informed Sport Certified, meaning each batch undergoes strict quality testing
  • Dairy-free, Gluten-Free, GMO-Free
  • Paleo Friendly
  • Better taste and texture than vegan proteins


  • On the expensive side (more than $2.00 per serving)
  • Only available in 2 flavors

Enter code FEASTGOOD10 at checkout to get 10% off.

Best Tasting: Rule 1 Whey

Check out our video review of Rule 1 Whey

Overall rating:

  • 3.9/5 

Key Features:

  • Price: $ ($1.07-$1.57 per serving)
  • Calories: 130-140 (depending on flavor)
  • Protein Content: 24g (69-74% calories from protein)
  • Sugar: 1g
  • Protein Source: Protein Blend: Whey Concentrate, Whey Isolate, Hydrolyzed Isolate
  • Potentially Constipating Ingredients: Whey (dairy), Lactose, Artificial Sweeteners
  • Likelihood to cause constipation on a scale of 1(low) to 5(extreme): 2

Our Thoughts:

Rule 1 Whey Blend has found the perfect balance between quality, taste, and value for whey proteins. 

They use a blend of 3 total types of whey protein. 

Two of these are whey isolate and hydrolyzed whey isolate, which contain virtually no sugar (lactose) but are more expensive sources of whey. 

They pair this with a third type, whey concentrate. It’s a less expensive whey protein but can contain unfiltered lactose. 

Because of the addition of whey concentrate, this product will likely contain more lactose than the isolate proteins outlined above and may be more reactive to people with lactose intolerances. 

In my experience, the total amount of sugar is still very low (1g or less), making it unlikely that this protein powder will cause constipation. I have included it on this list as someone with a dairy sensitivity who hasn’t had any issues using this product. 

Rule 1 Whey blend mixes up with a deliciously creamy texture and is available in 15 different flavors including Campfire S’mores, Cafe Mocha, and Chocolate Hazelnut. 

Rule 1 Whey uses sucralose and acesulfame potassium instead of stevia. If you find that you tend to be more reactive to stevia or find it to have a bitter aftertaste, then Rule 1 Whey may provide a more palatable and appealing option. 

At as low as $1.07 per serving, it provides the best value of any protein powder mentioned on this list. 

Don’t mistake a good value for poor quality, though. Rule 1 Whey is still Informed Choice Certified, which means the products and facility undergo regular testing for quality and purity. 

Check out my complete review of Rule 1 Whey Protein


  • Great taste and mixability
  • Inexpensive
  • A blend of 3 proteins, 2 of which are isolates, makes it more likely that this product contains very little lactose


  • Does use whey concentrate which typically has some lactose that hasn’t been filtered out
  • Uses artificial sweeteners and some flavors use food dyes which have potential adverse effects

Honorable Mention: Egg White Protein

I want to briefly mention another type of protein powder, egg white protein. 

This is another great option for people who are sensitive to dairy but don’t like the taste or texture of vegan protein powders. 

I am not including a specific recommendation because it has been many, many years since I have tried egg white protein powder, and neither I nor anyone else on the Feastgood.com team has tried the most popular ones available online.

Some are available from trusted brands, including BulkSupplements.com Egg Protein, but is only available in an unflavored option. 

What Causes Constipation From Taking Protein?

While there are a few reasons why protein powder might cause constipation, it’s becoming less and less common. 

The quality of protein powders has improved significantly over the past several years, and consumers have pushed for products with fewer cheap fillers and additives, which were some of the main causes of constipation and digestive upset in the past. 

In fact, even though I have lactose sensitivity, I can still digest most whey protein powders without issue. 

Furthermore, most people on social media complaining about constipation as a side effect of protein intake were from sources that were trying to sell vegan protein powders. There is an obvious bias here because the vegan sites will benefit from you thinking dairy-based protein is bad for you. 

That being said, if you are experiencing constipation from your protein powder, here are four potential culprits:

1. Lactose Intolerance

A lactose intolerance occurs when the body doesn’t produce the enzyme lactase required to break down lactose (milk sugar). 

Symptoms of lactose intolerance can include abdominal pain, bloating, or gassiness, but as many as 30% of individuals with lactose intolerance do experience constipation. 

If you suspect this might cause your constipation, try choosing a non-dairy option (like Vega Sport or ATP Supreme Beef Protein) or find a whey protein with 0g of sugar. 

2. Dairy Allergy

A dairy allergy, also known as Cow’s Milk Allergy, is a rare immune response in which the body mistakenly reacts to the proteins found in cow’s milk

While this affliction usually presents typical allergic reactions, ranging from rashes and digestive upset to difficulty breathing, it is technically a possible cause of constipation if you are consuming dairy-based proteins. 

If you suspect you might have a dairy allergy, avoid any dairy-based protein powders, including whey and casein proteins. Instead, try a vegan or beef protein powder like the ones outlined in this article. 

3. Low Fibre Intake

High-protein diets can promote feelings of satiety or fullness. As a result, individuals following a high protein diet might consume fewer other types of foods, which can result in lower total fiber intake. 

Along a similar thread, individuals following a high-protein diet with the goal of reducing body fat might purposely consume fewer carbohydrates, which could also contribute to a lower daily fiber intake. 

If you are certain you don’t have any of the dairy issues outlined above, track your daily fiber intake over a week (adults should aim for around 30g of fiber per day). 

To increase your fiber intake, incorporate a variety of fruits, vegetables, and whole grains into your diet or easily add ground psyllium husk to your protein shakes. 

4. Low Fluid Intake

Without going too deep into human physiology, protein digestion influences water levels in the body

Protein is broken down into amino acids, but for these amino acids to be used, the body first has to remove nitrogen from them. 

This nitrogen is initially released as toxic ammonia. The liver converts this ammonia into urea, which is then sent to the kidneys and excreted in the urine. 

As such, more protein consumption = more urea production = more urination, which can cause dehydration. 

While researchers did find that as individuals’ protein intake increased, the hydration status of these individuals decreased, the overall effect was interpreted as minimal. 

This can be easily mitigated by increasing your water intake throughout the day, with women aiming for around 9 cups (72oz) and men aiming for around 13 cups (104oz) of water daily. 

Possible Disruptor: Stevia and Artificial Sweeteners or Colors

The research around stevia, artificial sweeteners like sucralose, and food dyes is next to impossible to draw firm conclusions from. 

Whether you want to find research for or against using non-nutritive sweeteners, you can find research to support your position. 

Most of the studies are low-quality, meaning that they either have a low number of participants, didn’t control for many outside variables, or weren’t even done on humans at all but were done on rats or in vitro (e.g., in test tubes or culture dishes).

It is possible that consistent intake of stevia or artificial sweeteners can disrupt gut bacteria and cause symptoms like constipation.

 If you have tried all of the suggestions above (removing lactose/dairy, increasing fiber, and increasing water intake) but are still experiencing symptoms, choose a completely flavorless and colorless option like BulkSupplements.com Isolate

How Can I Incorporate Protein Powders Into My Diet Without Causing Constipation

I briefly covered a few different methods above to help prevent constipation when adding protein shakes to your diet, but here’s a quick summary of my top tips:

  • Take smaller, more frequent servings: For example, instead of taking two scoops of protein powder for breakfast or after a workout, cut back to a half scoop or a single scoop and space those out throughout the day. Research has shown that how much total protein you take in over the course of the day is more important than taking it at specific times (e.g. post-workout).
  • Mix your protein with enough water: Since protein can have an overall dehydrating effect due to the way amino acids are broken down and utilized, make sure to have at least 6-8oz of fluid per scoop when taking your protein powder.
  • Focus on daily fiber intake: You might be eating a lower calorie or lower carbohydrate diet in conjunction with your high protein diet. To help prevent constipation, adult women should aim for around 25g of fiber daily with men aiming for 30-38g.

Our Testing Methodology Explained 

At Feastgood.com, we pride ourselves on being honest and transparent in our reviews. Our team of Registered Dietitians, Nutrition Coaches, and Personal Trainers personally test any products we recommend. 

With regard to protein powders, we test them under various circumstances, including different times of day and mixed in different ways (e.g., with water, milk, yogurt, oatmeal, in recipes, etc.). 

We evaluate our products from multiple angles, including straightforward criteria like taste, quality, and mixability to unique aspects like ease of purchase, shipping, and presentation. 

Frequently Asked Questions

Can probiotics in protein powders help prevent constipation?

It’s unlikely that the probiotics in your protein will prevent constipation. 

Some probiotic strains may help alleviate constipation, but this is usually seen after multiple weeks of daily supplementation at high doses (10 Billion Cultures), whereas most proteins only contain 1-2 Billion cultures per scoop, if any. 

Are organic protein powders easier on the digestive system?

There is no significant difference in digestion between an organic protein powder and a non-organic protein powder. 

That said, plant-based protein powders can be easier on the digestive system than dairy-based proteins like whey and casein.

How do fiber supplements interact with protein powders?

Protein and fiber work well together to promote overall feelings of satiety and fullness. 

Pairing a fiber source with a protein powder can be a good way to prevent constipation or other negative digestive symptoms like bloating and gassiness and support overall health and well-being.


Spencer M, Gupta A, Dam LV, Shannon C, Menees S, Chey WD. Artificial Sweeteners: A Systematic Review and Primer for Gastroenterologists. J Neurogastroenterol Motil. 2016 Apr 30;22(2):168-80. doi: 10.5056/jnm15206. PMID: 26932837; PMCID: PMC4819855.

Leszkowicz J, Plata-Nazar K, Szlagatys-Sidorkiewicz A. Can Lactose Intolerance Be a Cause of Constipation? A Narrative Review. Nutrients. 2022 Apr 24;14(9):1785. doi: 10.3390/nu14091785. PMID: 35565753; PMCID: PMC9105309.

Pesta DH, Samuel VT. A high-protein diet for reducing body fat: mechanisms and possible caveats. Nutr Metab (Lond). 2014 Nov 19;11(1):53. doi: 10.1186/1743-7075-11-53. PMID: 25489333; PMCID: PMC4258944.

Liu M, Li M, Liu J, Wang H, Zhong D, Zhou H, Yang B. Elevated urinary urea by high-protein diet could be one of the inducements of bladder disorders. J Transl Med. 2016 Feb 16;14:53. doi: 10.1186/s12967-016-0809-9. PMID: 26879937; PMCID: PMC4755000.

Vadi S, Yim K. Hypernatremia due to Urea-Induced Osmotic Diuresis: Physiology at the Bedside. Indian J Crit Care Med. 2018 Sep;22(9):664-669. doi: 10.4103/ijccm.IJCCM_266_18. PMID: 30294134; PMCID: PMC6161575.

Martin WF, Cerundolo LH, Pikosky MA, Gaine PC, Maresh CM, Armstrong LE, Bolster DR, Rodriguez NR. Effects of dietary protein intake on indexes of hydration. J Am Diet Assoc. 2006 Apr;106(4):587-9. doi: 10.1016/j.jada.2006.01.011. PMID: 16567155.

Schoenfeld, B.J., Aragon, A.A. & Krieger, J.W. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr 10, 53 (2013). https://doi.org/10.1186/1550-2783-10-53

National Academies of Sciences, Engineering, and Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. https://doi.org/10.17226/10925.

About The Author

Jennifer Vibert

Jennifer Vibert is a Certified Strength and Conditioning Specialist, Nutrition Coach, and supplement store manager. She has a Bachelor of Kinesiology with a major in Fitness and Lifestyle and a minor in Psychology from the University of Regina. She is a Certified Nutrition Coach through Precision Nutrition, with a passion for helping clients learn the fundamentals of nutrition and supplementation in order to build healthy, sustainable habits.

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