Protein powder generally has no side effects if consumed in moderation. But there are certain side effects if it is taken in excess for a long period of time. Such as aggravating the burden on the liver and kidneys, causing indigestion, leading to calcium loss and so on. 1. Protein metabolism in the body will produce urea, ammonia, inosine and other nitrogenous substances, to be excreted through the kidneys. Overdose will aggravate the burden on the kidneys may lead to kidney failure. 2. Protein powder is a protein extracted from soybeans and contains a certain amount of estrogen, which may aggravate the condition of female patients suffering from breast hyperplasia and uterine fibroids if they consume too much. 3. Infants take a lot of it, it is easy to cause indigestion caused by diarrhea. 4. Excessive consumption of protein powder, easy to increase the loss of calcium in the urine because of excessive protein intake, which can damage the health of the bones, leading to osteoporosis and other diseases. Therefore, supplemental protein must be in moderation, the average person usually balanced diet can be, without additional supplemental protein powder, if you need to take please take under the guidance of professionals.