I believe the researched doses are something like 1500mg glucosamine and 1200mg chondroitin. Adding MSM is a bonus factor.
If you try it for 3 months and do not notice any change, quit. Definitely give it the three months though.
I always suggest ditching the nightshades first and foremost for joint pain...joint inflammation (especially more than one site) is a sign that inflammation is going on elsewhere in places that don't have the capacity to send pain signals (like internal organs)...