Melatonin is a hormone produced in the brain that helps regulate the body’s internal clock, also known as the circadian rhythm. Its main function is to signal that it is nighttime and that the body should begin winding down.
Melatonin does not act like a sleeping pill and does not directly cause sleep.
Melatonin production is closely tied to light exposure. As it gets darker in the evening, melatonin levels begin to rise. Exposure to light—especially from phones, tablets, and televisions—can delay or reduce this release.
In most people, melatonin levels increase at night and fall again in the morning. This pattern helps support normal sleep timing and daytime alertness.
Several common factors can affect melatonin timing, including inconsistent sleep schedules, evening screen use, shift work, travel across time zones, stress, and normal aging. When melatonin timing is disrupted, sleep may feel delayed, lighter, or less refreshing.
In addition to its role in sleep timing, melatonin is involved in other biological processes, including immune signaling and protection against cellular stress. Because melatonin affects multiple systems, changes in melatonin signaling can have effects beyond sleep.
Guidance from the American Academy of Sleep Medicine does not support the routine use of melatonin supplements for chronic insomnia.
There are several reasons for this:
Melatonin does not treat the underlying causes of insomnia
Evidence for benefit in chronic insomnia is limited
Over-the-counter products vary widely in dose and purity
Taking melatonin at the wrong time can worsen sleep
Long-term safety data are limited
For these reasons, melatonin is not considered a first-line or long-term treatment for insomnia. Behavioral and circadian-based approaches are more effective and better supported by evidence.
In certain circadian rhythm–related situations—such as jet lag, shift work–related sleep timing problems, or delayed sleep–wake phase—melatonin may be used as part of a structured treatment plan focused on adjusting sleep timing. In these cases, dose and timing are critical, and use should be guided by a healthcare professional.
It is also important to note that over-the-counter melatonin supplements are not regulated like prescription medications. More recent research has raised questions about melatonin use in individuals with certain medical conditions, including heart disease, reinforcing the need for caution.
From a sleep medicine perspective, the most effective way to support healthy melatonin rhythms is through consistent daily habits. Keeping regular sleep and wake times, limiting light exposure in the evening, avoiding screens before bed, and getting bright light exposure in the morning can all help reinforce the body’s natural sleep–wake cycle.
For patients with ongoing insomnia, the most effective and well-studied treatment is Cognitive Behavioral Therapy for Insomnia (CBT-I).
CBT-I focuses on:
Improving sleep habits and schedules
Reducing behaviors that interfere with sleep
Addressing thoughts and patterns that perpetuate insomnia
Unlike sleep medications or supplements, CBT-I is designed to treat the underlying causes of insomnia and has been shown to produce lasting improvements in sleep. For this reason, it is considered the preferred first-line treatment for chronic insomnia.
A sleep specialist can help determine whether CBT-I or another treatment approach is appropriate based on an individual’s sleep history and symptoms.
If sleep problems persist, supplements alone are unlikely to address the underlying cause. A sleep evaluation can help identify circadian rhythm disorders, sleep apnea, or other sleep conditions and guide appropriate, evidence-based treatment.
Educational Notice:
This content is provided for general educational purposes only and is not intended as medical advice. Patients should consult a qualified healthcare provider before starting or stopping any supplement.
