Evaluating sex differences in the formalin model of peripheral inflammatory pain – a systematic review and meta-analysis

More women are reported to suffer from chronic pain than men. It appears that women and men
process pain and respond to analgesics somewhat differently. However, preclinical research that
seeks to identify new analgesic targets in animal models of chronic pain has mainly used male
animals. Nevertheless, there is a substantial body of research that has used both sexes. Here, we
propose to systematically review these studies to establish the extent of sex differences. This review
will provide information that is essential to guide how we use data from animal models to identify
analgesics specific for both sexes.