Efficacy and Safety of Sustained-Release Melatonin Capsules (2 mg) in Healthy Adults with Poor Sleep Quality: A Randomized, Double-Blind, Placebo-Controlled Trial

Sleep disturbances and poor sleep quality are growing public health concerns, adversely affecting both physical and mental health. While exogenous melatonin supplements are used to manage the condition, there is limited evidence available on the efficacy of sustained-release (SR) melatonin formulations. This multicenter, randomized, double-blind placebo-controlled clinical trial evaluated the efficacy and safety of melatonin-SR capsules (2 mg) in healthy adults with poor sleep quality. Participants aged 30-60 years having poor sleep quality received melatonin-SR (2 mg) or a placebo capsule at night for 28 days. Changes from baseline till day 28 in polysomnography (PSG)-derived sleep parameters, Pittsburgh Sleep Quality Index (PSQI), WHO-5 Wellbeing Index, sleep diary parameters, and safety profile were evaluated. Of 62 enrolled participants, 59 (melatonin-SR, n=28; placebo, n=31) completed the study. Compared with placebo, melatonin-SR supplementation resulted in significant improvements at day 28 in PSG-derived sleep efficiency (P=0.001), and total sleep time (P=0.001), along with significant reductions in sleep onset latency (P=0.031) and wake after sleep onset (P=0.001). A significant reduction in PSQI global scores was observed in melatonin-SR group, from day 07 onwards (P=0.001). Improvement in subjective psychological well-being was significant from day 14 onwards (P=0.002). A significant improvement in subjective sleep parameters at day 28 (P<0.05) was observed. Reported adverse events in both groups were mild and transient in nature. Supplementation with melatonin-SR 2 mg capsule at night for 28 days was found to be effective and safe in improving objective and subjective sleep quality outcomes, and overall wellbeing in this trial population.