This thread seemed to fade away, but I found a Vital Proteins Collagen Peptides at Costco. 1 scoop of the chocolate flavor one is 45 calories, fat is 0.25g, protein 10g, carbs 2g, 0 added sugar. The unflavored one has no carbs at all.

I put a scoop of it it in my egg white protein smoothies and don't see any weight gain effect from it. Undoubtedly there are probably other collagen powders that have more "stuff" and sugar, carbs etc. in them. This one seems benign. I don't know if I'd drink it all by itself, though, but it's certainly fine in a smoothie like I make.

Does it help anything? I have no idea, hopefully it does good things to skin and joints etc.