Does move free really work

I've only experienced my knee pain since this March 2012, but it has been a constant pain. I tried OTC meds, rx drugs and pt. none worked. I finally tried Move Free, being very skeptical. I also started taking magnesium oxide. I don't know if it was either supplement or a placebo effect, but my pain was gone within two weeks. Whatever it is, I'm just happy to be pain free.