Can anyone advise me on Great Lakes colleges/ gelatin

Hi, I read somewhere on a previous post about how this had helped ease a few peoples stiff joints and it was recommended. I checked it out on Amazon where it was said the poster purchased it only to find a few bad comments on how it had never been tested and how the packet doesn't give a break down of what is in it. So you could be putting anything in your body.I was ready to buy it until I read this. Could any of you that has used it give me any feed back please.