Epigallocatechin Gallate: meta-analysis of COVID-19 studies

All studies Hospitalization Serious outcomes Cases RCTs Peer-reviewed All outcomes

Outcome (studies)

Improvement

Relative risk · 95% CI

All studies (2)38%

Hospitalization (1)67%

Cases (1)1%

RCTs (2)38%

Prophylaxis (1)67%

Late (1)38%

00.511.5+

← EGCG
reduces riskIncreased
risk →

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c19early.org

October 2026

Epigallocatechin gallate COVID-19 studies

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Zhu (RCT)38%0.62 · 0.50–0.90no improv.30/7623/38aerosolized EGCG

Late treatment38%0.62 · 0.43–0.9130/7623/3838% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.015

Kawai (RCT)67%0.33 · 0.01–8.15hosp.0/5031/500green tea gargling

Prophylaxis67%0.33 · 0.01–8.150/5031/50067% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.51

All studies38%0.62 · 0.43–0.9030/57924/53838% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.01300.511.52+

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← EGCG
reduces riskEGCG
increases risk →

c19early.org

October 2026

Epigallocatechin gallate COVID-19 hospitalization results

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kawai (RCT)67%0.33 · 0.01–8.15hosp.0/5031/500green tea gargling

Prophylaxis67%0.33 · 0.01–8.150/5031/50067% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.51

All studies67%0.33 · 0.01–8.150/5031/50067% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.5100.511.52+

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← EGCG
reduces riskEGCG
increases risk →

c19early.org

October 2026

Epigallocatechin gallate COVID-19 serious outcomes

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kawai (RCT)67%0.33 · 0.01–8.15hosp.0/5031/500green tea gargling

Prophylaxis67%0.33 · 0.01–8.150/5031/50067% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.51

All studies67%0.33 · 0.01–8.150/5031/50067% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.5100.511.52+

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← EGCG
reduces riskEGCG
increases risk →

c19early.org

October 2026

Epigallocatechin gallate COVID-19 case results

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kawai (RCT)1%0.99 · 0.59–1.67cases27/50327/500green tea gargling

Prophylaxis1%0.99 · 0.59–1.6727/50327/5001% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.98

All studies1%0.99 · 0.59–1.6727/50327/5001% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.9800.511.52+

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← EGCG
reduces riskEGCG
increases risk →

c19early.org

October 2026

Epigallocatechin gallate COVID-19 Randomized Controlled Trials

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Zhu (RCT)38%0.62 · 0.50–0.90no improv.30/7623/38aerosolized EGCG

Late treatment38%0.62 · 0.43–0.9130/7623/3838% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.015

Kawai (RCT)67%0.33 · 0.01–8.15hosp.0/5031/500green tea gargling

Prophylaxis67%0.33 · 0.01–8.150/5031/50067% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.51

All studies38%0.62 · 0.43–0.9030/57924/53838% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.01300.511.52+

Rotate screen for more detailsIncrease width for more details

← EGCG
reduces riskEGCG
increases risk →

c19early.org

October 2026

Epigallocatechin gallate COVID-19 peer reviewed studies

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Zhu (RCT)38%0.62 · 0.50–0.90no improv.30/7623/38aerosolized EGCG

Late treatment38%0.62 · 0.43–0.9130/7623/3838% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.015

Kawai (RCT)67%0.33 · 0.01–8.15hosp.0/5031/500green tea gargling

Prophylaxis67%0.33 · 0.01–8.150/5031/50067% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.51

All studies38%0.62 · 0.43–0.9030/57924/53838% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.01300.511.52+

Rotate screen for more detailsIncrease width for more details

← EGCG
reduces riskEGCG
increases risk →

c19early.org

October 2026

Epigallocatechin gallate COVID-19 outcomes

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Zhu (RCT)38%0.62 · 0.50–0.90no improv.30/7623/38aerosolized EGCG Zhu (RCT)57%0.43 · 0.26–0.70no improv.71 (n)37 (n)aerosolized EGCG Zhu (RCT)90%0.10 · 0.02–0.57no improv.71 (n)37 (n)aerosolized EGCG Zhu (RCT)74%0.26 · 0.10–0.72no improv.71 (n)37 (n)aerosolized EGCG Zhu (RCT)53%0.47 · 0.19–1.14no improv.71 (n)37 (n)aerosolized EGCG Zhu (RCT)38%0.62 · 0.23–1.72no improv.71 (n)37 (n)aerosolized EGCG Zhu (RCT)36%0.64 · 0.15–2.67no improv.71 (n)37 (n)aerosolized EGCG Zhu (RCT)9%0.91 · 0.18–4.50no improv.71 (n)37 (n)aerosolized EGCG Kawai (RCT)67%0.33 · 0.01–8.15hosp.0/5031/500green tea gargling Kawai (RCT)67%0.33 · 0.01–8.15progression0/5031/500green tea gargling Kawai (RCT)1%0.99 · 0.59–1.67cases27/50327/500green tea gargling Kawai (RCT)18%0.82 · 0.44–1.55cases386 (n)403 (n)green tea gargling Kawai (RCT)18%0.82 · 0.42–1.56cases386 (n)403 (n)green tea gargling

00.511.52+

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← EGCG
reduces riskEGCG
increases risk →