15 Side Effects Of Whey Protein You Should Be Aware Of

While this dietary supplement may be beneficial for your health, beware of its ill effects too.

Reviewed by Mayuri Aavula, MSc (Nutrition)
By Tanya Choudhary, ISSA Certified Specialist In Fitness & Nutrition

Whey protein is commonly used as a supplement to build muscles and keep your cholesterol levels under control. While the benefits of whey are many, a lot of people do not know about the several side effects of whey protein on your health. In this article, we take a deeper look at the adverse effects of consuming too much whey protein.

Whey Protein – A Brief

Whey protein in a measuring scoop


Although whey protein is considered to be a supplement that is safe, it is best not to go overboard with it. When you consume it more than you should, it can lead to a number of health problems. This risk is even higher when your intake of carbohydrate is low. Milk contains two types of protein; one of them is whey protein. It is water soluble and is used to meet the daily protein requirements. It also provides large amounts of L-cysteine, the amino acid. This amino acid helps in the alleviation of deficiencies that come with conditions such as diabetes aging (1).

Experts call whey protein the “complete protein” as it is rich in all the amino acids required by the human body to repair muscles, bones, tissues, organs, etc. Other complete proteins are foods such as eggs, meat, dairy, etc. One of the pros of whey protein is that it is easy to digest quickly.

[ Read: Side Effects Of Protein Supplements ]

Benefits Of Whey Protein

Although whey protein is consumed as a supplement, it is much more than that. It is a functional “super food” that helps immensely in the regulation of your body weight. It also helps in increasing muscle mass, and comes with many other health benefits. The health benefits that this nutrient provides are linked directly to the amino acid profile it has. This complete protein is also highly rich in antioxidants, making it an effective fighter against various diseases and a great promoter of overall health.

Here is a look at some of the benefits that you can gain by moderately consuming whey protein supplement of high quality on a regular basis:

  1. It helps in promoting weight loss.
  2. It helps in increasing muscle mass in the body.
  3. It helps in the treatment of cancer.
  4. It helps in reducing the symptoms that come with HIV.
  5. It helps in increasing the levels of glutathione in your body.
  6. It helps in lowering triglyceride levels in the body.
  7. It helps in lowering cholesterol levels while increasing good cholesterol or HDL.
  8. It helps in boosting the proper function of the immune system.
  9. It helps in increasing power while playing sports.
  10. It helps in lowering recovery time and the symptoms that come with over-training.

As you can see, there are quite a few benefits to gain from whey protein intake. The trick is to make sure that you do not take too much of it. Instead of gaining its goodness, you can end up with side effects that may not seem too severe but can be highly uncomfortable. If you have kidney, liver or heart problems, it is especially important to moderate your intake of whey protein and also get your doctor’s advice before you start making it a part of your daily diet.

When Should One Take Whey Protein?

Woman adding a scoop of whey protein to her milk


This is a question that is often asked by many people who are interested in consuming whey protein but do not know how to go about it properly. It is not tough to learn when to take this protein to reap its benefits.

Firstly, if you want to take whey protein on its own, you should do it within half an hour to an hour after a workout that is based on strength training. This is because this protein gets digested very quickly. During other times, you should eat it with other foods so that digestion can be slowed down. For instance, for extra protein in your breakfast without foods like eggs, you can add whey protein to your oats in powder form.

Secondly, if you want to have a healthy snack while you are in the office, you can have a whey protein-shake combined with a bit of fish oil or nuts. This again will help in slowing down the digestion process of the protein. The fat combination is what helps slow down digestion and this in turn benefits you greatly by allowing the levels of insulin in your body to stay even. It also aids in the stimulation of CCK, which is a hormone that lets your body know when it is full.

Protein that is digested after a workout gives your body the amino acids that it needs for the repairing and building of new muscles. According to experts, consuming whey protein as soon as you complete a workout could be especially beneficial as it has a rich content of Leucine, an amino acid that is easily absorbed by the body.

Whey Protein Side Effects

Although whey protein has many benefits, it does come with quite a few side effects as well. Here is a look at fifteen of the adverse effects that this protein can have on your body:

1. Excessive Fat Gain:

In many cases, whey protein supplements have extra carbohydrates in the form of sugars. There are some that have fats as well. This means that weight can be gained in fat form, which is unhealthy. You can also gain weight when you overeat while consuming whey protein at the same time.

2. Kidney Stone Formation:

When you consume whey protein, there is a risk of kidney stone formation. While it may not be a direct cause, experts believe that this protein can make the condition worse if you are already suffering from it. To prevent this, you should take adequate quantities of dietary fiber and water.

3. Digestive Problems:

Woman suffering from digestive problems as a side effect of whey protein


Lactose is present in whey protein, and if you are sensitive to it, you could end up having problems with digestion. It is not only people who are lactose intolerant that suffer from this problem. If you do have digestive problems, opt for a whey protein concentrate as it does not contain as much lactose. Whey protein isolate, which is more refined, can deplete good bacteria in your gut and might cause digestive problems such as constipation, gas, bloating and stomach pain.

[ Read: Side Effects Of Soy Proteins ]

4. Risk Of Gout:

Although there is no evidence that whey protein is a direct cause of gout, it can worsen the problem if you already have it. It is also best to consult a physician before you start taking whey protein if there is a history of gout in your family.

5. Kidney Problems:

Excessive intake of whey protein can cause renal problems, especially if you already suffer from them. Experts recommend monitoring your whey protein intake and also consulting your physician before you start taking it. This way you can avoid any long-term damage to your kidneys.

6. Liver Problems:

Consuming whey protein excessively can worsen liver problems (2). This is why it is important to make sure that you consume the protein moderately at all times. It is also advisable to consult your doctor before taking whey protein, as it may interfere with the effects of the medication you are taking for your liver condition.

7. Risk Of Heart Disease:

Experts believe that consuming too much whey protein can have dangerous effects on people who suffer from heart disease. It can cause cardiac arrest, heart rhythms that are abnormal, and as well as complete loss of heart functionalities.

8. Blood Acidity Increase:

Another side effect of whey protein consumption is an escalation of pH in blood. When there is too much protein in your blood, the kidney has problems in metabolizing it. This results in the increase of blood acidity.

9. Development Of Osteoporosis:

This disorder has been linked to excessive intake of whey protein. This is especially risky with long-term intake of the protein. Consuming whey protein in high amounts can cause mineral imbalance in the bones which in turn can lead to the depletion of the density of bone minerals.

10. Fatigue And Weakness:

Due to the digestion problems that some people suffer from when they consume whey protein, they can also go through adverse effects such as extreme fatigue as well as weakness. They may also suffer from bloating, gas, cramps, etc. This is because some people’s bodies can’t process or break down the protein that they consume.

11. Development Of Ketosis:

This is another common side effect of whey protein consumption. This is a condition that occurs when abnormal levels of ketone bodies are present in the blood (3). If you put yourself on a diet that is low in carbohydrate and high in protein, energy is burnt in the body using fat. When there is no fat, protein is used. This puts immense pressure on the liver and causes damage over time.

12. Diarrhea:

Woman suffering from diarrhea as a side effect of whey protein


Another side effect of excessive whey protein consumption is diarrhea. It is a part of the effect that this protein has on the digestive system. There can even be blood in the stool, especially among infants.

13. Wheezing:

Many people often have an allergic reaction to whey protein, especially if they are lactose intolerant. Such people can have difficulty breathing and may suffer from symptoms like wheezing. If you go through this symptom, you should consult a physician immediately.

14. Swelling Of Throat, Mouth, Lips:

Another symptom that comes with an allergic reaction to whey protein is the swelling of the throat, mouth, and lips. Although it may not be painful, it can be extremely uncomfortable, and it is best to see a doctor to make sure that no severe damage has been done.

15. Nausea:

This is one of the common side effects of taking whey protein. In quite a few cases, people also suffer from vomiting. The key to avoiding this uncomfortable side effect is to cut down on your intake of the protein.

How Safe Are Whey Protein Supplements?

Are you aware of the serious side effects of whey protein supplements? It has been established that the amount of whey protein supplements you consume has a direct influence on whether you gain from its benefits or not. Over-consumption of this protein is the reason many people suffer from adverse effects. In fact, excessive consumption of any protein is bad for the body as it gets stored in the body in the form of fat. This in turn increases the risk of dehydration.

There is also the chance that whey protein may have an interaction with certain medications. For example, it has been found that supplements made with this protein can reduce the effectiveness of Levodopa, which is a drug used for Parkinson’s disease. Whey protein supplements may also lower the effectiveness of Alendronate, the drug prescribed to patients with osteoporosis. It may lower the body’s ability to absorb the drug, thereby making it less effective. It may also have an adverse effect on the effectiveness of the antibiotics Tetracycline and Quinolone. It should also be noted that diabetic patients may experience blood sugar changes when they consume protein supplements.

To make sure that whey protein supplements are safely consumed, experts recommend moderate doses on a short-term regimen. This way, the body gets the benefits of the protein without the risk of suffering from any of these whey protein side effects that have been mentioned above. They also recommend whey protein supplements for athletes or people who are physically active than for those who are not. This is because athletes or people who work out on a regular basis require more protein than people who are not physically active.

Infographic: The Components Of Whey Protein

Whey protein is a much-talked-about supplement amongst health and fitness enthusiasts. It is mostly available in powdered form and provides high-quality nutrition owing to its readily absorbable vital amino acids content. Rapid muscle healing and muscle growth are the main benefits of this protein source. In addition, it can also boost immune response. But what is whey protein composed of?

Check out this infographic to learn more about the individual components of whey protein and their role in maintaining overall health.

components of whey protein [infographic]

Illustration: StyleCraze Design Team

Whey protein is a popular dietary supplement with many health benefits. It is a complete source of protein and may help you build muscle, recover from exercise, and lose weight. However, there are some unexpected side effects of whey protein. Most people believe that consuming more protein supplements (more than the recommended dosage) may help them with faster results. But overconsumption of whey protein may cause excessive fat gain, kidney stone formation, digestive problems (especially in those who are allergic to cow milk or with lactose intolerance), gout formation, and renal issues. It may also worsen liver problems, cause cardiac arrest, increase blood acidity, increase osteoporosis risk, and lead to fatigue and weakness. Excess intake may also lead to drug interaction and increase the risk of dehydration. Consult your health care provider before using any whey protein supplements, especially with respect to the recommended dosage to avoid any adverse reactions. In addition, if you are under any medication, check your portions and ensure your whey protein is safe to consume. Consume whey protein in moderation to reap its maximum benefits.

Frequently Asked Questions

Can I drink whey protein without working out?

Yes, whey protein can be consumed even without working out. However, if consumed excessively, without a workout regimen, it may lead to weight gain.

Does whey cause hair loss?

No, whey protein does not cause hair loss. There is no scientific evidence to support this claim.

Can I take whey protein twice a day?

Yes, you may take whey protein twice a day. However, after reaching the desired weight, it is ideal to consume it once a day post-workout.

Was this article helpful?
The following two tabs change content below.
Tanya is an ISSA certified Specialist in Fitness & Nutrition. She specializes in writing articles on ingredients that benefit skin,... more

Mayuri Aavula

(MSc (Dietetics))
Mayuri Aavula is one of the top nutritionists in Hyderabad, India, and has won several awards and accolades. She started... more