I once had an acupuncturist tell me that if you have tendon problems, you can buy beef tendon at a Chinese grocery store and boil it for several hours (like bone broth; boil it until it dissolves) and then drink it like a broth. I believe it is very high in collagen. It doesn't taste bad, just like strong beef broth.
There is also a product called Arthred (made by Source Naturals) that is hydrolyzed collagen and that I believe is used for arthritis. I knew a very talented natural practitioner who used this in his practice. Unfortunately, the product is somewhat expensive, and you have to use it for quite a while before you know whether it is working. Of course, if it's not working, you've already spent quite a bit of dough by that point. I was using this product for some other issues (not arthritis), and I complained about the price to my acupuncturist, who told me to get the beef tendon from the Chinese grocery.
