Usually the people who should not use collagen are as follows: first, the body primary metabolic dysfunction, such patients should not supplement too much protein, especially collagen, there will be protein intolerance, because the primary body lack of protein metabolism enzyme, there will be too much supplemental protein bloating, abdominal pain, nausea, vomiting, thin stools, etc., collagen will appear loss and excretion. Second, if the body protein is too high, biochemical examination of the body albumin, globulin, albumin ratio are too high should not eat collagen, otherwise the body protein content is too high, will lead to a series of cardiovascular disease, but also lead to hyperlipidemia. The third, gastrointestinal intolerance should not eat collagen, there is a serious upper gastrointestinal bleeding, gastric esophagogastric venous dilatation or serious peptic ulcer, should not eat collagen for a long time, or affect the gastric mucosa acid reflux, heartburn and other digestive tract symptoms.