Side Effects of Protein Supplements

Does Too Much Whey Protein Cause Side Effects?

Whey Protein Sport NutritionWhey protein is one of the most popular supplements on the planet.

But despite its many health benefits, there’s some controversy surrounding its safety.

Some claim that too much whey protein can damage the kidneys and liver.

The key difference between the three main types of whey protein is how they are processed.

Whey protein concentrate: Contains 70–80% protein.

It’s the most common type of whey protein and has more lactose, fat and minerals from milk.

Whey protein isolate: Contains 90% protein or more.

It’s more refined and has less lactose and fat, but it also contains fewer beneficial minerals.

Whey protein hydrolysate: This form is predigested, allowing your body to absorb it faster.

Whey protein is the most popular choice among athletes, fitness enthusiasts and people wanting to build muscle or lose weight.

Does It Cause Digestive Issues?Bloated Belly

Some people have problems digesting whey protein and experience symptoms such as bloating, gas, stomach cramps and diarrhea.

Most of these side effects are related to lactose intolerance.

Lactose is the main carbohydrate in whey protein.

People who are lactose intolerant don’t produce enough of the enzyme lactase, which your body needs to digest lactose.

If you are lactose intolerant, try switching to a whey protein isolate powder.

Whey protein isolate is more refined, with a much smaller amount of fat and lactose than whey protein concentrate. People with lactose intolerance can usually safely take whey protein isolate.

Other options would be a non-dairy protein powder, such as egg, soy, pea, rice or hemp protein.

Could You Be Allergic To Whey Protein?

People with a cow’s milk allergy may be allergic to whey protein.

However, it is very rare for adults to have cow’s milk allergies, since up to 90% of people with cow’s milk allergies outgrow them by the age of three.

Symptoms of a cow’s milk allergy may include hives, rashes, facial swelling, throat and tongue swelling and a runny or stuffy nose.

In some cases, a cow’s milk allergy may trigger anaphylaxis, a severe, life-threatening allergic reaction.

A lactose intolerance could very easily be confused for an allergic reaction.

Constipation and Nutritional Deficiencies Caused By Whey Protein…?

Whey protein cannot be blamed for any constipation that may result when someone has removed fruit and vegetables from their diet in favor of whey protein when they are on a low-carb diet.

Fruits and vegetables are a great source of fiber, which helps form stool and promotes regular bowel movements.

Whole foods, especially fruits and vegetables, are nutrient-rich and contain a variety of minerals necessary for optimal health.

It’s important to keep eating a balanced diet while you’re taking whey protein.

Kidney or Liver Damage…??Kidneys

Eating a high-protein meal can raise the pressure inside the kidneys and cause them to filter more blood than usual.

But, this does not mean that a high-protein meal harms the kidneys of healthy people.

That said, there is evidence that a high-protein diet can be harmful for people with kidney disease.

A high-protein diet in those with kidney disease may further damage the kidneys.

It is always advised to check with your doctor before beginning a supplement to make sure it is safe for them…that goes for everyone!

The liver needs protein to repair itself and convert fats to lipoproteins, which are molecules that help remove fats from the liver.

There is no evidence that too much protein can damage the liver in healthy people. However, people with liver disease should check with their doctor about whether whey protein is safe for them.


Whey protein is safe and many people can take it without any problem.

It may cause digestive symptoms in those with lactose intolerance, and those allergic to cow’s milk may be allergic to it.

If you experience side effects, try a whey protein isolate or non-dairy protein alternative.

Whey protein is one of the best supplements on the market. It has a wide range of benefits in strength and muscle building, recovery and weight loss.

If you have any questions or comments, please feel free to leave them below.

Thanks for reading!




  1. Good information to know. I had issues with it this past summer. But didn’t really discover what t was till later on. I’m happy to see you’re putting this info out there.

  2. It seems that if one can take the whey protein in moderation then it will be safe for them. This is like anything that we consume. Once we over indulge it ma cause some negative effects. Thanks for the information rich article.

  3. I have used whey protein for years and did not know that there are three different types until I read your post! This was very enlightening. Do you think that plant based protein powders are as effective as whey protein? Is there any benefit switching to plant based proteins if I do not have any allergies or negative effects from whey?

    • Hi Mike!
      Thanks so much for the post! Great questions. Lots of opinions out there about which protein is more effective – plant-based or whey. I think it is personal preference. As far as any benefits to switching to a plant-based protein…maybe less bloat, or gas, if that was an issue with whey protein…??

  4. Hi Chris,
    Great article. Thank you for writing this to help dispel some of the myths of protein and educate people. I still hear people talking about high protein diets causing health problems even though they’ve never tried it. I have found over the years that most who thought they had problems with whey protein were using a low quality form of it and felt great once they switched to one that wasn’t filled with garbage.

    • So true Dan…it’s all about the quality. Don’t even waste your money on poor quality protein powder. Stick with the reputable names. They aren’t even the most expensive ones out there;) Just do your research.

  5. I am such a newbie when it comes to this! I really did not realize that there was so much lactose in whey protein.

    I have just started using a protein powder in my shakes in the morning and I really like it. It makes me full for most of the day and I get a lot of energy too.

    I haven’t taken anything out of my diet – so from your post I should be safe from the side effects you have listed.


  6. I tried whey protein supplements before and like you say, had some stomach problems.

    I’m usually not allergic to milk products although I don’t consume a lot of those. That is why some time ago I wanted to try whey supplements.

    I’ll try the isolated version now. Before reading this here I didn’t think of that, thanks.

  7. Very interesting article. I decided to enroll myself to a fitness gym, I wanted to go on a diet and I was told about taking whey protein will help me build muscle (Ihave more fat than muscle unfortunately).

    Because of that, I also wonder if taking whey protein will be fine for I am a lactose intolerance. So reading your post answered my question! Thank you so much.

    I think I’ll be checking your site often.

Leave a Reply to admin Cancel reply

Your email address will not be published. Required fields are marked *