Shark cartilage has a rather bad reputation. This link covers some of the concerns:-
http://en.wikipedia.org/wiki/Shark_cartilage
By all means try the various supplements, but I feel I ought to add that there are studies showing that advanced glycation end products, derived from cooking, negatively affect cartilage:-
http://www.ncbi.nlm.nih.gov/pubmed/11822407http://www.ncbi.nlm.nih.gov/pubmed/12483725http://ard.bmj.com/content/64/6/886.fullhttp://arthritis-research.com/content/6/S3/78/
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While I understand that you love to cook, it might be a good idea, given the above data, to cook at lower temperatures and, especially, to cook in moisture(ie boiling/marinating) as that helps to lower somewhat the amounts of advanced glycation end products in cooked foods. Oh, and avoid grainfed meats as these have higher levels of AGEs than grassfed or wild meats.
Geoff