Farnoosh · Archives of medical research 2022 · randomized double-blind controlled trial · n=74

Efficacy of a Low Dose of Melatonin as an Adjunctive Therapy in Hospitalized Patients with COVID-19: A Randomized, Double-blind Clinical Trial.

Cited 84 times in the scientific literature.

Level 2 - randomized trial

Single-center randomized, double-blind controlled clinical trial.

PubMed 34229896 · doi:10.1016/j.arcmed.2021.06.006 · record verified 2026-08-29

What was done

In a single-center, double-blind randomized clinical trial in Tehran, Iran, 74 hospitalized patients with confirmed mild-to-moderate COVID-19 were randomized 1:1 to standard of care alone or standard of care plus melatonin (3 mg three times daily) for 14 days. Clinical symptoms, C-reactive protein (CRP), and radiological pulmonary involvement were evaluated baseline to post-intervention, with safety and clinical outcomes tracked for 4 weeks.

What was found

Only 44 patients completed treatment (24 in the melatonin group, 20 in the control group). The melatonin group showed statistically significant improvements compared with controls in cough, dyspnea, fatigue, CRP levels, and pulmonary involvement (all p < 0.05; exact figures not reported in the abstract). Mean time to hospital discharge and return to baseline health were significantly shorter in the melatonin group (p < 0.05). Zero deaths and zero adverse events occurred in either arm.

Why it matters

This study provides randomized trial evidence that low-dose adjuvant melatonin may accelerate recovery and shorten hospital stays for mild-to-moderate COVID-19 at low cost.

Limits

The abstract omits exact point estimates, effect sizes, and confidence intervals for all outcomes. The sample size is small, conducted at a single hospital, and experienced high post-randomization dropout (30 of 74 enrolled did not complete treatment), raising potential attrition bias. Findings cannot be generalized to severe or critical COVID-19.

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