• Statistically significant improvements are seen for mortality, ventilation, ICU admission, hospitalization, recovery, cases, and viral clearance. All remain significant after exclusions. 58 studies from 52 independent teams in 22 different countries show statistically significant improvements in isolation (40 primary outcome, 38 most serious outcome).• Meta analysis using the most serious outcome shows 62% [51‑70%] and 83% [74‑89%] improvement for early treatment and prophylaxis, with similar results after exclusion based sensitivity analysis, for primary outcomes, for peer-reviewed studies, and for RCTs.• Results are very robust — in worst case exclusion sensitivity analysis 58 of 92 studies must be excluded to avoid finding statistically significant efficacy.• No treatment, vaccine, or intervention is 100% effective and available. All practical, effective, and safe means should be used based on risk/benefit analysis. Multiple treatments are typically used in combination, which may be significantly more effective. Only 23% of ivermectin studies show zero events with treatment.• Over 20 countries adopted ivermectin for COVID-19. The evidence base is much larger and has much lower conflict of interest than typically used to approve drugs.• All data to reproduce this paper and sources are in the appendix. See [Bryant, Hariyanto, Kory, Lawrie, Nardelli] for other meta analyses with similar results confirming efficacy.