I have been taking glucosimine for over 3 years now.
The other supplement is called condroitin. You can get a pill with both combined. I like EAS's version which is seperate pills. It is reccomended that you take 1500mg of one and 900 mg of the other, which is 3 pills a day.
I had walked with a limp caused by bursitis in my hip for over 3 years, and noticed great improvement in decrease of pain in just under 30 days.
It is not a overnight wonder drug, it takes a while for it to start working.
I heard about it from someone who played tennis, and had elbow pain, so it works on most joints.