Although also not without risk, my understanding is that Metacam is safer if you want to use a pharmaceutical product.
Others with more experience will be able to provide information on supplements.
My Rickie was on Metacam for awhile after joint fusion surgery and still, very occasionally, for a few days if he overdoes something and limps.
As a preventative I give him Cosequin which has recently been superseded by Flexadin - both are made by Nutramax Labs and my understanding is that there is a fair bit of clinical research behind the products. Not cheap though.