Hydrogen peroxide as auxiliary treatment for COVID-19: A randomized double-blind clinical trial

Di-Domênico, Marielle Bazzo; Collares, Kauê; Dos Santos, Renan Brandenburg; Lenz, Ulysses; Antunes, Vinícius Picoli; Godinho, Vinicius Webber; Cesca, Henrique; Ponciano, Thales Henrique Jincziwski; Corazza, Pedro Henrique

Objectives: Evaluate the effectiveness of hydrogen peroxide (H2O2) as mouthwash and nasal spray on the relief of symptoms for COVID-19 patients. Methods: Patients positive for SARS-CoV-2, treated in hospital or at home, and patients' family members (not positive for SARS-CoV-2), were randomized into two groups: experimental (1% H2O2 for gargling, 0.5% H2O2 for nasal wash), and control. Patients gargled the solution three times a day, and applied nasal spray twice a day, for a seven-day period. Family members received the same treatment as their treated index patient. The researchers contacted patients every two days, over eight days. An average post-treatment interval of eight days passed before testing family members. Results: The most frequent symptoms on day 0 were cough, loss of taste, and hyposmia, with no difference between groups, independent of the period. The symptom dyspnea presented significance between days 2 and 4 (p=0.04). Among family members, 86% had no antibodies, 2.3% had antibodies, and 11.6% had active infection: 4, experimental group; 6, control group. The most frequent adverse effects for the H2O2 group were burning throat and nose. Conclusion: H2O2 is not effective for the relief of symptoms of COVID-19 and is associated with reports of transient adverse effects.