I used chondroitin/glucosamine for 5 years with zero results.  I was in such pain that I obtained a referral from my doctor to consult an orthopedic surgeon. I had to wait 3 months for an appointment. I did not want to endure the pain for that length of time and did not want to use prescription medications so I shopped around for other options. I ran across GLM.  I began taking it (double dose for the first 6 weeks) and by the time my appointment came around, I was pain free and much more mobile. I thought maybe it was just coincidental. So I quit taking the muscle and 4 weeks later the pain was back. So, I began taking it again and the pain was gone within 3 weeks. I still was not convinced. Once again I quit and the pain returned. By then I was a believer. I have been pain free now for 2 years. I have also used it for a extremely painful torn rotator cuff. And my son used it for a fractured clavicle. I would not be without it.  No side affects at all and it's very inexpensive.