It's becoming quite usual that people older than ¿30-40? years old complement their diet with collagen for bones and specially articulations-related issues. I know some of them which use it as a preventive method.
My doubt arises when thinking that it's just a protein molecule, so as far as I know it will be subdivided into amino acids before reaching our bloodstream.
Since these amino acids are so ordinary and can be found in so many nutrients aside from collagen molecules, what's the point of ingesting pure collagen? Would it be really useful or completely unnecessary?
PD: Since the comment where I said it has "disappeared" I want to thank here @Nate Barbettini his appropriate help.