Whey Protein Side Effects

What is Whey Protein

whey protein side effectsWhey protein is actually a mixture of proteins extracted from whey. In case you didn’t know, whey is a by-product resulted after cheese production. Before I state here the whey protein side effects, here are the health effects of this supplement.

Whey Protein Health Effects

Whey protein is used in general as a dietary supplement for muscle building and for increasing athletic performance. However, various studies have shown that whey protein doesn’t only has minimal beneficial effects towards muscle growth. On the other hand, whey protein reduces the risk of heart disease. Also, various studies have shown that whey protein might have anti-cancer and anti-inflammatory properties, and there are ongoing studies regarding the positive impact of whey protein on the prevention of diabetes.

In general, due to the fact that whey protein is a good source of amino acids, especially branched-chain amino acids, it stimulates the synthesis of protein which the body uses to fuel up the muscles. From the branched-chain amino acids contained by whey protein, leucine has the most significant role in the protein synthesis. Therefore, by consuming a high amount of whey protein, the protein synthesis undergoes a much better stimulation, the body adapts better to physical stress and recovers much quicker after exercising, especially after lifting heavy weights.

Whey Protein Side Effects

Among the most common whey protein side effects are gastrointestinal problems, like nausea, gas, bloating, or and in worst cases diarrhea and blood in the stool. Whey protein side effects concerning the digestive tract occur mostly due to the lactose intolerance of the consumer. If consumed in high quantities, a big part of the whey protein might not be completely digested and in the colon, it will go through a bacterial fermentation process which leads to bloating, gas or diarrhea.

Other whey protein side effects that the user may experience are: fatigue, somnolence, headaches.

Individuals that are allergic to cows’ milk it’s likely to also experience an allergic reaction to whey protein, or to develop allergy symptoms. Whey protein side effects of this nature are: skin rash, hives, breathing problems, facial edema, or swelling of the lips, mouth or tongue. In general, allergic side effects like these occur between half an hour and two hours from the intake off whey protein. Anyway, in case you have lactose intolerance or you’re allergic to lactose, you shouldn’t consume this supplement.

Whey Protein Interactions

One of the whey protein side effects is that it can interfere with the absorption of certain drugs. Levodopa is one of them. This drug is usually prescribed to patients with Parkinson’s disease and dopamine-responsive dystonia. In any case, if under medication with this drug, you should ask for the advice of a physician if it’s safe to supplement with whey protein. Also, whey protein may diminish the absorption of tetracycline, quinolone and aledronate.


In general, whey protein side effects are rather rare. The most common side effects associated with this supplement are digestive issue, and these digestive issues are usually experienced by people who consume a high amount of this supplement.

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