Table 1.
Summary of findings from studies that included melatonin supplementation in the COVID-19 treatment.
| References | Study design, setting, gender, age | Therapy, regimen | N, severity of COVID-19, and comorbidities | Outcomes |
|---|---|---|---|---|
| Mousavi et al. (33) | RCT; Hospital; Female (55.2%); 52.9 ± 1.8 years. | •Group 1 (N = 48): a single nightly 3 mg oral melatonin tablet for 7 days or until death. •Group 2 (N = 48): no supplementation (ST). |
N = 96; Severity of COVID-19: NR; Comorbidity: DM (28.1%), asthma (5.2%) renal failure (10.4%), cardiovascular disease (15.6%), hypertension (30.2%), thalassemia (3.1%), thyroid disorders (8.3%), COPD (3.1%). | •LSEQ: ↑ melatonin group compared to CG. •WBC count, lymphocyte count, CRP: no difference on day 7. •Blood oxygen saturation: improved in the melatonin group. •On day 10: one patient from the melatonin group died vs. 3 patients in the CG. |
| Alizadeh et al. (34) | RCT; Hospital; Male (55.7%); 36.0 ± 1.5 years. | •Group 1 (N = 14): two tablets (6 mg) per day of melatonin for 2 weeks. •Group 2 (N = 17): no supplementation (ST). |
N=31; Mild to moderate COVID-19; Comorbidity: Patients with comorbidities were excluded from the study. | •CRP1, CRP2: no difference between the groups. •% of the recovery in the melatonin group: higher in males. •Percentage of normal CRP: higher in females in the melatonin group but lower in the CG. |
| Farnoosh et al. (35) | RCT; Hospital; Male (59.1%); 51.8 ± 0.2 years. | •Group 1 (N = 24): 3 mg of melatonin three times daily for 14 days. •Group 2 (N = 20): no supplementation (ST). |
N = 44; Mild to moderate COVID-19; Comorbidity: hypertension (25%), DM (23%), rheumatic disease (9%), cardiovascular disease (7%). | •Improvement of respiratory symptoms (coughs, dyspnea) and fatigue in the melatonin group compared to CG. •Improvement in the level of CRP, time of hospital discharge, and pulmonary involvement in the melatonin group compared to CG. •Melatonin group showed a return baseline health sooner compared to CG. |
COVID-19, coronavirus disease 2019; CG, control group; NR, not reported; DM, diabetes mellitus; CRP, C-reactive protein; mg, milligram; ST, standard therapy; LSEQ, Leeds sleep evaluation questionnaire; WBC, white blood cell; COPD, chronic obstructive pulmonary disease; ↑, increase.