I purchased a 20 day bag of Advanced COLLAGEN . I'm a 77 year old man and purchased it mostly for my Joint health and rebuilding . Type ll and lll collagen is suppose to be for that. 20 days is a short trial period but I do think it has been helping . Having ALL 5 types of collagen is a PLUS for skin, nails etc, but my biggest concern is Joints / Knees etc. I have been using their " Advanced Amino's " for over a year and I do know they have been helping me , especially since I have been taking them twice a day away from meals hopefully on an empty stomach, I can feel / know they have been giving me more strength . I would probably be able to say more about the Collagen if I would have been taking it for a longer period of time.