Melatonin is a hormone and neurotransmitter which regulates sleep. While available as a dietary supplement, some professional societies still discourage its use due to insufficient evidence.

A new meta-analysis seeks to address this shortcoming by reviewing 23 RCTs that evaluated sleep quality using the Pittsburgh Sleep Quality Index and conducted subgroup analyses on participants with respiratory disease, metabolic disorders, sleep or mental disorders.

1. The Basics

Melatonin is produced by the pineal gland in the brain and circulated throughout the body to signal to our circadian clock that night has come. Our master clock governs our day/night cycle as well as each cell and organ’s intrinsic circadian rhythms; any disruption to this master clock through exposure to light at night or stress can have far reaching implications, leading to disorders beyond just sleep/wake cycles, potentially even leading to serious diseases such as dementia and Alzheimer’s.

Samueli Institute’s Rapid Evidence Assessment of Literature (REAL) process identified 35 RCTs that met criteria for evaluating melatonin’s effectiveness at improving sleep or optimizing its quality, such as in shift workers to balance out their sleeping/waking patterns, jet lag sufferers to reduce delayed onset effects, insomniacs to facilitate restful slumber, or healthy volunteers improving outcomes related to efficacy, somnolence or hormone phase shift changes.

SME researchers carefully examined each study individually and reached consensus on its findings before employing GRADE methodology to formulate recommendations for using melatonin across four user categories.

While I lauded his accomplishment, my heart did break slightly at his passing. The experts reached a strong consensus for using melatonin to restore sleep/wake patterns of shift workers and those experiencing jet lag, to reduce symptoms of insomnia in both military and nonmilitary populations, and to enhance outcomes related to initiating sleep and improving its efficacy for healthy volunteers. As they could not make any recommendations regarding the use of melatonin to improve hormonal phase shift changes among healthy volunteers, no recommendations could be made as yet regarding its usage for such purposes. It was stated that before such recommendations could be issued large and long-duration RCTs of melatonin were conducted on young healthy adults before making such recommendations. Exogenous melatonin should also be combined with other therapies in order to maximize its benefits as an aid for sleep support. Reduce blue light devices in the bedroom; create and stick to an effective bedtime routine; avoid stimulants like coffee, nicotine and alcohol before sleep; and strive for healthy nutrition to support natural melatonin production in your body.

2. The Science

Melatonin plays an integral part in our sleep cycles and circadian rhythms, as well as other essential body processes. It regulates internal clocks, sleep-wake cycles and the production of numerous essential chemicals; furthermore it has other physiological benefits such as helping us regulate immune systems and metabolize fats more effectively.

Supplemental melatonin may help people sleep better; however, not everyone needs or should use it under medical advice. Melatonin may interact with certain medications like sedatives and antidepressants so it’s important to inform your physician of all medications taken prior to using melatonin.

Melatonin is naturally produced in both the brain and throughout the body by the pineal gland, acting as an effective antioxidant and anti-inflammatory. Melatonin supports healthy cell function while also regulating temperature, immune system activity and metabolism – as well as controlling appetite.

Your sleep hygiene and avoidance of stimulants such as caffeine can help increase melatonin production, while making adjustments to your bedroom environment can enhance it as well. For instance, keeping the room cool and dark at bedtime may encourage increased production; in addition, cutting back exposure to blue light at night may decrease production further.

Studies examining melatonin for its potential to improve sleep have examined its use among shift workers to regulate their sleep-wake cycle; those suffering from jet lag to reduce symptoms associated with disrupted circadian rhythms; and individuals struggling with insomnia to encourage restful nights’ rest.

Recent RCT reviews demonstrated the efficacy of melatonin for improving multiple outcomes studied, such as sleep latency, duration and quality. Higher doses were linked with greater improvements in these aspects.

3. The Dosage

Melatonin is an effective hormone that regulates our sleep/wake cycles, though not everyone needs the same amount. When your natural circadian rhythm becomes disrupted due to travel or night shift work, or due to any other causes that interfere with sleeping patterns, taking melatonin supplements could be an invaluable way to get back on track and achieve restful slumber.

Melatonin is produced in the brain and secreted through the pineal gland, but its production can be disrupted with excessive light exposure at night, medication use or diet high in sugar or processed food, or simply age itself resulting in insomnia and nightmares.

Melatonin has long been used as a supplement in both the US and Canada to aid sleep. Additionally, multivitamin and mineral products often include it to enhance restfulness during the night, making melatonin an over-the-counter drug option in many countries.

As with all medications, it’s essential that you understand potential side effects before beginning to take melatonin supplements. Melatonin should generally be considered safe when taken according to instructions; it’s also vital that you don’t exceed recommended dosage limits as too much melatonin could have adverse side effects and interfere with sleep quality.

Start slowly by starting with 1 or 2 mg and monitoring how you respond before increasing your dosage. Take your first dose about an hour before bedtime; daily dosage shouldn’t exceed 10 mg.

Review of Melatonin Literature Published Since 1999 showed that, using GRADE assessment methodology, weak recommendations could be made for its use in shift workers and individuals with jet lag to restore balance to their sleep-wake cycle, persons with insomnia for sleep improvement and healthy volunteers for improving outcomes related to efficacy, somnolence and hormonal phase shift changes (Table 2 for full description of included studies). Further large and high quality RCTs would strengthen evidence supporting its use among these populations.

4. The Impact

Sleep is an essential human need that plays an integral part in our health and wellbeing, yet many individuals struggle to get adequate and high-quality restful slumber due to factors like chronic disease or poor lifestyle choices.

Melatonin is a hormone produced in the pineal gland to facilitate sleep, released upon detection of darkness and decreasing body temperature to induce sleep. Melatonin provides feedback to the suprachiasmatic nucleus clock which regulates circadian rhythms; additionally it may have indirect effects by modulating peripheral oscillators in our circadian network.

Melatonin can also help treat delayed sleep-wake phase syndrome (DSPS), insomnia, and fibromyalgia. According to research, melatonin improves DSPS sleep quality by shortening time to fall asleep, increasing total duration, and decreasing morning grogginess; furthermore it has also been demonstrated to decrease time awake during the night.

Even with this promising evidence, professional societies do not recommend melatonin for treating secondary sleep disorders due to insufficient clinical trials. This is mostly because studies have only shown improvements in specific aspects of sleep such as onset latency and total time sleep; other aspects, including architecture or circadian timing of waking/sleeping cycles might remain unchanged as it quickly leaves systemic circulation after release or administration (via supplementation or exogenous).

Establishing good sleep habits and creating an ideal sleeping environment are keys to getting more restful slumber, including creating a regular bedtime ritual, limiting screen exposure in the evenings, avoiding stimulants and alcohol intake, as well as making sure your bedroom is dark, quiet, cool and has comfortable bedding such as mattresses and sheets.

Melatonin can be beneficial, but the top recommendation from medical professionals is improving sleep hygiene. Even those who create an ideal environment, limit exposure to blue light screens, and use comfortable bedding may still wake up feeling disoriented because their natural rhythms have been disturbed by daily life stressors and environmental influences.