Cissus, chondroitin, glucosamine, fish oil and a diet high in Omega-3s have been helpful to me for joint pain.
Also, even if you're pretty solid you should do a form check and make sure that everything is looking good as far as form goes. I've found that in attempts to go heavy sometimes form will inadvertently be sacrificed, and although it may get you through a set in the short term, the long term risks are not fresh.
Good luck, brother.