Protein Shakes Side Effects

by on January 7, 2012


Side effects associated with protein shakes are extremely rare when this product is used responsibly and in moderation. The most common side effects are associated with lactose intolerance as many of these supplements contain whey protein from cow’s milk. Side effects with products such as these are nearly always associated with heavy use of the product in conjunction with an unhealthy diet.

Common Protein Shake Side Effects

protein shakes Protein shakes must be used carefully to get the benefits of this product without sustaining any damage. Protein shake side effects can range from mildly uncomfortable to very dangerous. The most common side effects include the following:

  • Cramping
  • Bloating
  • Weight gain
  • Dehydration
  • Acne
  • Diarrhea

When these side effects are mild, they can generally be managed by reducing consumption of the protein shakes and balancing the protein in your diet with more carbohydrates. If you experience severe instances of the above side effects, you should contact your healthcare provider.

Serious Protein Shake Side Effects

Many protein shakes are made with whey protein. This protein is obtained from cow’s milk. If you are lactose intolerant, you may react poorly to whey protein powder. You should be aware of the protein shake side effects associated with an allergic reaction and contact your doctor if you experience any of the following

  • Severe stomach cramps
  • Excessive bloating
  • Upset stomach
  • Gas
  • Nausea

Other serious side effects may include:

  • Hair loss or total baldness
  • Nutritional deficiencies associated with an imbalanced diet


Protein shake side effects in association with weight are difficult to define. The manner in which you use the protein shakes will ultimately determine the effect they have on your weight. Protein shakes can significantly increase your total calorie intake if you do not make alterations to the rest of your diet. Simply adding protein shakes as a beverage on top of your standard meals and snacks may result in serious weight gain since you will be consuming so many more calories. Though some individuals believe that weight gain from these shakes will occur in the form of muscle, there is no evidence to prove this theory.

On the opposite end of the spectrum, protein shake side effects may include noticeable weight loss if you are replacing meals with protein shakes. Protein shakes also cause dehydration which could quickly rid the body of water weight. This is not a healthy weight loss solution. You may shed extra pounds, but your body is not getting the nutrients or hydration it needs in this situation. Protein shakes should be accompanied by at least 8 to 10 glasses of water a day as well as a full balanced diet.


Osteoporosis is one of the many dangerous protein shake side effects you may experience with excess use of this product. High levels of protein in the body make the blood more acidic. The body will respond to this by leeching calcium from the bones and sending it into the bloodstream.

Without adequate protein, the bones and joints will become weak and prone to fractures. This is one of the most damaging protein shake side effects because osteoporosis is a long-term consequence that cannot be cured.

Kidney Stones

As mentioned above, side effects include highly acidic blood which causes the body to pull calcium into the bloodstream to compensate.

While your bones are suffering from the lack of calcium, your kidneys may be suffering from the excess. High levels of calcium can cause small crystallized calcium deposits known as kidney stones to form. These are then passed through the urine in a very painful manner.

Symptoms of side effects associated with kidney stones include the following:

  • Severe lower abdominal pain
  • Blood in the urine
  • Extreme pain passing urine
  • Night sweats
  • Night fevers

Consuming adequate amounts of water in conjunction with protein shakes may help decrease the likelihood of developing kidney stones. If you are experiencing problems with kidney stones, you should reduce or completely stop your use of protein shakes.


When used as part of a low carb diet, side effects may include ketosis. Health professionals disagree on the danger of ketosis occurring in the body. When the body does not receive enough carbs, it breaks fat down into ketones and essentially puts itself into starvation mode. Some doctors warn that this can lead to long term liver damage while others contend that this process is actually beneficial for the body. Discuss the matter with your doctor if you plan on switching to a high-protein low-carb diet.

Most protein shake side effects are not associated with the protein shakes themselves, but rather with the diet and exercise routine that often accompanies this product.

If you consume protein shakes in moderation along with plenty of water, a healthy exercise regimen and a balanced diet, you should not experience any adverse protein shake side effects. If you are concerned about how protein shakes will impact your body, discuss your diet with your doctor.