Metronidazole: meta-analysis of COVID-19 studies

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

Outcome (studies)

Improvement

Relative risk · 95% CI

All studies (1)−20%

ICU admission (1)−20%

Hospitalization (1)25%

RCTs (1)−20%

Late (1)−20%

00.511.5+

← Metronidazole
reduces riskIncreased
risk →

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c19early.org

October 2026

Metronidazole COVID-19 studies

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kazempour (SB RCT)−20%1.20 · 0.19–7.77ICU2/202/24

Late treatment−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.86

All studies−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.8600.511.52+

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← Metronidazole
reduces riskMetronidazole
increases risk →

c19early.org

October 2026

Metronidazole COVID-19 ICU results

StudyImprovementRR · 95% CITreatmentControlRelative Risk

Kazempour (SB RCT)−20%1.20 · 0.19–7.772/202/24

Late treatment−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.86

All studies−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.8600.511.52+

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← Metronidazole
reduces riskMetronidazole
increases risk →

c19early.org

October 2026

Metronidazole COVID-19 hospitalization results

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kazempour (SB RCT)25%0.75 · 0.01–47.18hosp. time20 (n)24 (n)

Late treatment25%0.75 · 0.01–47.1820 (n)24 (n)25% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.9

All studies25%0.75 · 0.01–47.1820 (n)24 (n)25% lower risk

Tau² = 0.00, I² = 0.0%, p = 0.900.511.52+

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← Metronidazole
reduces riskMetronidazole
increases risk →

c19early.org

October 2026

Metronidazole COVID-19 serious outcomes

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kazempour (SB RCT)−20%1.20 · 0.19–7.77ICU2/202/24

Late treatment−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.86

All studies−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.8600.511.52+

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← Metronidazole
reduces riskMetronidazole
increases risk →

c19early.org

October 2026

Metronidazole COVID-19 Randomized Controlled Trials

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kazempour (SB RCT)−20%1.20 · 0.19–7.77ICU2/202/24

Late treatment−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.86

All studies−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.8600.511.52+

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← Metronidazole
reduces riskMetronidazole
increases risk →

c19early.org

October 2026

Metronidazole COVID-19 peer reviewed studies

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kazempour (SB RCT)−20%1.20 · 0.19–7.77ICU2/202/24

Late treatment−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.86

All studies−20%1.20 · 0.19–7.772/202/2420% higher risk

Tau² = 0.00, I² = 0.0%, p = 0.8600.511.52+

Rotate screen for more detailsIncrease width for more details

← Metronidazole
reduces riskMetronidazole
increases risk →

c19early.org

October 2026

Metronidazole COVID-19 outcomes

StudyImprovementRR · 95% CIOutcomeTreatmentControlRelative Risk

Kazempour (SB RCT)−20%1.20 · 0.19–7.77ICU2/202/24 Kazempour (SB RCT)25%0.75 · 0.01–47.18hosp. time20 (n)24 (n) Kazempour (SB RCT)−43%1.43 · 0.11–19.33oxygen20 (n)24 (n)

00.511.52+

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← Metronidazole
reduces riskMetronidazole
increases risk →