A systematic literature search was conducted on April 12th 2019 on Embase to identify meta-analyses of rodent studies. To these, we added one other meta-analysis retrieved from other sources. **Search string:** (rodent*[ti] OR "mice"[ti] OR "mouse"[ti] OR rat*[ti]) AND (meta-analys*[ti] OR metaanalys*[ti]) This is by no means a comprehensive search, but it is sufficient for our **aim**: to describe a distribution of sample sizes and effect sizes of preclinical literature. Given our search strategy, our description is biased towards those fields in which meta-analyses are performed. The following information were retrieved: 1. sample size 2. effect size (type and quantification) 3. year of publication 4. field of research (e.g. neuroscience, metabolism, cancer, drug research...) To the information extracted in text, we added data from available csv files, as well as a meta-analysis from our own group (at the time available only as preprint). Files description: - **embase_records_20190412.xlsx** : records as downloaded from embase - **embase_records_20190412_extracted.xlsx** : inclusion/exclusion with reasons. Contains 3 separate sheets: one for sample size (n), one for effect sizes, and one for meta-data on the articles. - **other_datasets** : contains all data files (.csv, .xsls ...) freely available from the identified meta-analyses The datasets of embase_records_201912_extracted.xlsx and other_datasets were then merged in three separate files: - meta_effectsize.csv - meta_n.csv These files can be found in the parent directory, and are the final files used for analysis.