Are there any side effects to over-consuming whey protein?

Doctor's Answer

This is a good question. Whey protein is the most common and popular supplement for fitness enthusiasts who want to increase their muscle mass asap.

Whey protein is generally safe and can be consumed by most people without side effects.

A commonly suggested dose is 1–2 scoops (25–50 grams) per day, but it’s recommended that you follow the serving instructions on the package.

Taking more than this is unlikely to offer more benefits, especially if you already eat enough protein in your normal diet.

Potential side-effects:

1. Digestive issues

Most of whey protein’s side effects are related to digestion.

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

2. It can worsen pre-existing kidney issues

There is evidence that a high-protein diet can be harmful for people with kidney disease.

On the other hand, whey protein is safe for those with normal kidney function. A detailed review of 74 studies on protein’s effects on the kidneys concluded that there is no reason to restrict protein intake in healthy people.

3. It can worsen pre-existing liver issues

There is no evidence to show that too much protein can damage the liver in healthy people.

However, a high protein intake may harm people who have cirrhosis, a chronic liver disease.


Whey protein is very safe in general. Especially for those who do not have any medical conditions.

If in doubt, please seek formal medical advice from a trusted doctor!

Hope this helps!

Warmest regards,

Dr Justin Boey

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