Knowledge of the antiseptic effects of hydrogen peroxide (H2O2) dates back to the late 19th century, and its mechanisms of action has been amply described. Globally, many physicians have reported using H2O2 successfully, in different modalities, against COVID-19. Given its anti-infective and oxygenating properties, hydrogen peroxide may offer prophylactic and therapeutic applications for responding to the COVID-19 pandemic. We report a consecutive case series of twenty-three COVID-19 patients (of 36 initially enrolled) who had been diagnosed by their primary care physician (mean age: 39, range: 8 months–70 years; 74% male) and twenty-eight caregivers in the Mexico City Metropolitan Area who received a complementary and alternative medicine (CAM) telemedicine treatment with H2O2 taken by mouth (PO, at a concentration of 0.06%), oral rinse (mouthwash, 1.5%), and/or nebulization (0.2%). We describe the treatment program and report the response of the COVID-19 patients and their caregivers. The patients mainly recovered well, reporting feeling “completely better” at 9.5 days on average. Two (9%) were hospitalized prior to joining the study, and one did not fully recover. Patients frequently reported nausea and sometimes dizziness or vomiting related to the oral treatment. None of the twenty-eight caregivers in close contact with the patients reported contracting COVID-19. Given its low cost and medical potential and considering its relative safety if used properly, we suggest that randomized controlled trials should be conducted. These should include both SARS-CoV-2-positive and SARS-CoV-2-negative participants, with single or combined modes of administration of H2O2, to study the benefits of this simple molecule and offer safe guidance regarding its use by health professionals.