CRD Summary: This review concluded that the present evidence does not support the use of Botulinum toxin A injections for trigger points in myofascial pain. This was generally a well-conducted review and the authors’ cautious conclusions are likely to be reliable.

CRD Commentary: The review question and inclusion criteria were clear and well-defined.  An appropriate search was carried out using multiple databases with no language restrictions applied, thereby minimising the likelihood of important studies being missed.  However, only published studies were eligible for inclusion, which introduces the risk of publication bias.  Study quality was assessed using two standardised scales, and aspects of study design affecting reliability and validity were also discussed in the text.  The study selection and validity assessment processes were carried out by more than one reviewer, but there is insufficient detail to determine whether the data extraction was carried out independently. The possibility of error and bias at this stage of the review process cannot, therefore, be ruled out.  There was a high level of heterogeneity between the included studies in outcome measures, dosages, inclusion criteria and location of TPs, thus the decision to combine the results in a narrative was appropriate. This was a generally well-conducted review and the authors’ cautious conclusions are likely to be reliable.