41year old male, very athletic. I have no explanation for what has happened since I first began using this collagen, as I'm not a doctor, but I'm certainly not complaining. I'm an avid weight lifter and both of my shoulders had been absolutely killing me for months. The pain would come and go at times. It was so bad for those 3-4 months that I was completely unable to sleep on my side at all. I thought I needed surgery it was so bad. My doctor said it was most likely Bursitis that was flaring up and to just keep doing PT work with them and that was about it. Finally I decided to look into collagen. This one was the first one I came across. Reviews looked good so I placed an order. I began taking 3 servings a day. By the end of that first week my shoulder pain went from about an 8 down to a 1 or 2! I was absolutely shocked, and very much relieved. I ended up running out of collagen before ordering another and lo and behold the pain came right back while I anxiously awaited the arrival of my package. To this day I still don't know what's going on with my shoulders but all I do know is this stuff is a LIFE SAVER! 10/10 HIGHLY recommend