I injured my left knee in a car accident many years ago. My knee would usually only hurt when the weather changed and got colder. A few years ago, though, it started hurting all the time. I couldn't sit on the floor or cross my leg without excruciating pain. I saw a knee doctor who told me to take glucosamine and chondroitin. The bottle says you have to take it for awhile before you get the full effects, but I noticed almost immediately after taking a pill that the pain was better. Now I only take them when the pain flairs up, which it hasn't done in awhile.
My mom suffers from really bad arthritis. She asked her arthritis doctor about taking it--Mom was told that her type of arthritis would not respond to glucosamine.
The only other affect that I ever noticed was that it made me have more bowel movements. I took the chewable kind, in raspberry flavor that I got from The Vitamin Shoppe
Hope you get to feeling better!