Efficacy of Melatonin as an Adjunctive Therapy in Hospitalized Patients with Mild to Moderate COVID-19: A Randomized, Double-blind Clinical Trial

Melatonin has proven antioxidant and anti-inflammatory properties that may address the pathophysiology of coronavirus disease 2019 (COVID-19). Therefore, the current study was conducted to evaluate the safety and efficacy of melatonin in COVID-19. In this single-center, randomized, double-blind, placebo-controlled clinical trial, 96 adults hospitalized with mild to moderate COVID-19 were recruited. The participants were allocated into the melatonin and the placebo groups, randomly (1:1 ratio). The primary outcomes were a reduction in the length of hospital stay, the rate of ICU admissions, intubation/mechanical ventilation, and mortalities within 14 days of starting the treatment compared to the placebo group. After two weeks of follow-up, the blood oxygen saturation and the respiratory rate significantly improved in the melatonin group. C-reactive protein, erythrocyte sedimentation rate, lactate dehydrogenase, creatine phosphokinase, Ferritin, and D-dimer levels were significantly decreased in the melatonin group. Conversely, these markers were considerably increased in the placebo group. These serum marker levels also showed a significant difference in between- group comparison. The comparison of clinical endpoints between the two groups showed no significant difference. This clinical trial study indicated that the combination of oral melatonin tablets and standard treatment could substantially improve blood oxygen saturation and inflammatory factors in mild to moderate hospitalized COVID-19 patients.