We present a meta-analysis that examines the association between the degradation of biomolecules and cellular elements found within blood and its TSD. The primary goals here are to determine the strength of these relationships and whether certain analytical techniques and biomolecules provide more robust blood TSD estimates. Specifically, we i) determined the mean effect size -a quantitative value measuring the strength of a relationship -of bloodstain TSD studies, ii) explored how effect sizes varied by class of biomolecule, analytical technique, substrate porosity, blood source, temperature, and type of summary statistic, and, iii) searched and analyzed compiled data for a publication bias. By using a meta-analytic approach, we synthesized quantitative data on blood TSD estimates, complementing recent qualitative reviews . The combination of quantitative and qualitative data provides a holistic overview and way forward for bloodstain TSD research and ultimately, crime scene implementation.