Does melatonin improve sleep quality?
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
The Efficacy of Melatonin in Improving Sleep Quality
Introduction to Melatonin and Sleep Quality
Melatonin, a hormone produced by the pineal gland, plays a crucial role in regulating the sleep-wake cycle. Its production is influenced by the light-dark cycle, with higher levels produced at night. This hormone has been widely studied for its potential to improve sleep quality, particularly in populations with sleep disorders.
Melatonin and Sleep Quality in the Elderly
Research indicates that melatonin can significantly improve sleep quality in elderly individuals. A study involving 12 elderly subjects with insomnia found that controlled-release melatonin significantly increased sleep efficiency and reduced wake time after sleep onset compared to a placebo. Another study with a larger sample size of 170 elderly patients demonstrated that prolonged-release melatonin improved sleep quality and morning alertness without causing withdrawal effects.
Melatonin's Impact on Cancer Patients
Patients with cancer often experience sleep disturbances due to their condition and treatment. A systematic review of studies on melatonin's effects on sleep quality in cancer patients found that melatonin significantly improved sleep quality and reduced insomnia in most studies reviewed. However, some studies did not find significant improvements, suggesting variability in response among different patient groups.
Perioperative Sleep Quality and Melatonin
Perioperative sleep disorders are common and can complicate recovery. A meta-analysis of randomized controlled trials (RCTs) found that melatonin improved postoperative sleep quality, increased total sleep time, and enhanced sleep efficiency. The analysis suggested that a 6 mg dose of melatonin was particularly effective.
General Efficacy of Melatonin in Sleep Disorders
A comprehensive meta-analysis of 23 RCTs concluded that melatonin significantly improves sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI) in adults with various health conditions, including respiratory and metabolic disorders. Another meta-analysis focusing on primary sleep disorders found that melatonin reduced sleep onset latency, increased total sleep time, and improved overall sleep quality.
Melatonin in Critically Ill Patients
In critically ill patients, melatonin supplementation was associated with better sleep quality as assessed by the Richards Campbell Questionnaire Sleep (RCSQ). The study found that melatonin significantly improved sleep quality compared to a placebo, although it did not significantly affect the duration of night sleep or the occurrence of delirium.
Dietary Sources of Melatonin
Dietary sources of melatonin, such as milk and sour cherries, have also been studied for their potential to improve sleep quality. A review of randomized, placebo-controlled trials suggested that these food sources might be beneficial in promoting healthy sleep, although more research is needed to confirm these findings.
Conclusion
Overall, the evidence supports the efficacy of melatonin in improving sleep quality across various populations, including the elderly, cancer patients, perioperative patients, and those with primary sleep disorders. While the degree of improvement can vary, melatonin generally shows a positive impact on sleep efficiency, sleep onset latency, and total sleep time. Further research is needed to optimize dosing and understand the long-term effects of melatonin supplementation.
Sources and full results
Most relevant research papers on this topic