Whey protein is basically a risk-free supplement and has no known significant negative side effects. It is advised that you must adhere to the serving guidelines mentioned on the packaging of the product. If you are a lactose intolerant person and suffer from side effects after its consumption, then you must try switching to the whey protein isolate variant, as it is lactose-free and contains little to no sugar or artificial sweeteners. You can get your hands on the best quality isolate whey protein in order to extract the benefits of whey protein to the fullest.