However, findings from different laboratories, often from small studies, are inconsistent. Systematic reviews and meta-analysis are techniques to provide an unbiased and transparent summary of existing research [13, 14]. They can be helpful in the design of clinical trials [15, 16] and in understanding discrepancies between the results of preclinical and clinical trials . Here, we report a systematic review and meta-analysis to appraise d-galactose-induced brain ageing as a prevalent ageing model in rodent.