Your good friend, collagen does have the function of firming the skin, and can't be used as an elixir at the same time. Any product has the same effect on anyone. Some people use it obviously, while others don't. This operating table is the same as surgery, the same surgery, the same doctor, some people can continue their lives healthily after surgery, and some people will stay on the operating table forever. Don't you think so? No one can 100% answer your question.