I am also trying to learn about collagen. I know who Dr McCormick is but who is Margie Bissinger?

I agree, Dr McCormick is extremely knowledgeable. I own both his books and am considering a consult with him. I have the utmost respect for him. On the subject of collagen, I think there are a lot of unanswered questions about what specific types are helpful. I actually contacted McCormick with questions about the product he sells and he said "great questions" but conceded that he wasn't sure which type of collage was best for bones, marine or bovine or if the bovine source in the product he sells is completely sourced from grass fed cows. I've contacted Gelita with those questions as I can't find that info on their website. More independent studies are definitely needed. I do take collagen with the hopes that it is helpful. I just don't know if there is anything particularly special about Fortibone.