I've seen ads for enzyme supplements that are meant to be taken on an empty stomach, with claims that they act "systemically" to enhance all sorts of body functions. In particular they claim that such supplements help heal sports injuries and remove scar tissue (excess fibrin). Of course, they also claim their pills to be "proven effective by numerous clinical studies". The specific enzymes in one popular supplement include: pancreatin, papain, bromelain, trypsin, chymotrypsin, and rutosid. On the other hand, I've read that all enzymes taken orally are broken down (like any other protein) before entering the bloodstream, rendering such supplements worthless. So, are these enzyme supplements bogus? Or is there a grain of truth amidst the hype?