An Annals of Internal Medicine meta-analysis and an accompanying editorial argue strongly for the lack of efficacy of chondroitin for the treatment of osteoarthritis of the knee and hip. Last year, folks were talking about the GAIT trial which seemed to show that the hydrochloride form of glucosamine plus chondroitin did not help overall in that RCT but it might have helped in those with moderate or severe pain.An editorial paired with the NEJM article reporting on the GAIT trial reminded readers that previously data has suggested that the sulfate form of glucosamine seemed to work while the hydrochloride form perhaps did not.
Now it looks like there is little or no reason to add chondroitin to glucosamine sulfate even though many of the available preparations combine the two if we are to accept the results of the meta-analysis. But remember it is a meta-analysis and often it all turns on which studies you include and which you do not. The authors admit there was much heterogeneity and many of the trials the could have included were judged to be of such poor quality that they were excluded. One can hardly expect the truth to emerge from any type of analysis of trials that were poorly done to begin with so a case can be made for selectivity but... Meta-analyses are so common place now that editorial caveats about their weaknesses are generally no longer mentioned but they should be and my earlier blog on that topic contained a couple of good references.
The editorial paired with the GAIT trial suggested that one might still want to give the following advice: Try the combo of glucosamine sulfate with chondroitin for three months or so and if no better stop the pill. Now maybe it would be to just try the glucosamine sulfate.