Before embarking on this review, we generated a standard protocol for this and all other Cochrane Reviews performed by our group. The protocol was approved by the Editorial Board of the Cochrane Musculoskeletal Review Group (CMSG), but, as an update, did not result in a specific publication in the Cochrane database. We deviated from the standard protocol with respect to the selection of main outcomes and analysis. The main outcomes specified in the protocol were pain and function, as recommended for osteoarthritis trials. After approval of the standard protocol, the Editorial Board of CMSG reconvened several times to establish common views on how to conduct systematic reviews, and it was decided that the main outcomes of future reviews should reflect both effectiveness and safety. CMSG further agreed to recommend the use of a maximum of two main outcomes. Therefore, the CMSG Editorial Board and the authors of this review agreed to specify pain intensity and the number of drop‐outs or withdrawals due to adverse events as main outcomes for this update. Function was specified as one of the secondary outcomes. The protocol specified that our main analysis would be based on standardised mean differences (SMDs) derived from inverse‐variance random‐effects meta‐analysis. In view of the high degree of heterogeneity, the predominance of small trials of low methodological quality and the skewed funnel plot for pain intensity as one of the main outcomes, we refrained from presenting the SMD of pain as primary result in main body of text and summary of findings table, but reported results from uni‐variable meta‐regression analysis used to predict treatment effects in trials as large as the largest trials included in the meta‐analysis with the standard error as the explanatory variable. We acknowledge that this analysis is exploratory, however. In addition, we used 'Risk of bias' tables to present the methodological quality of included trials and a 'Summary of findings' table to present results.