HomeHealth articlessleep disorderDoes Melatonin Help With Insomnia?

Melatonin for Sleep - A Narrative Review

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Melatonin is a supplement used in the treatment of sleep problems. Read below to know in detail.

Medically reviewed by

Dr. Basuki Nath Bhagat

Published At June 28, 2023
Reviewed AtJune 30, 2023


The melatonin hormone is secreted by the brain’s pineal gland. Melatonin production is highest at night, and light stops its production. Therefore, melatonin regulates the body’s circadian rhythm (the biological clock). Many individuals experience sleep deprivation. Hence, they use melatonin supplements to facilitate sleep.

What Are the Advantages of Melatonin Supplements?

Over the past few decades, prescriptions for sleep medications have increased manifold. As a result, patients use various medications, such as Benzodiazepines. These medications cause many adverse effects. Hence, synthetic melatonin is available as a dietary supplement for sleep disorders. It is available as tablets, capsules, lozenges, syrups, and other preparations. It is generally safe, with fewer side effects. Various advantages include:

  1. Melatonin is a Food and Drug Administration (FDA) approved supplement for sleep.

  2. It ameliorates sleep quality in patients with insomnia.

  3. Various studies suggest a favorable profile of melatonin in jet lag patients.

  4. There are no dose restrictions for melatonin. It is because it does not lead to a hangover effect or dependence.

  5. Melatonin can also improve eye health due to its antioxidant effects.

What Are the Sleep Disorders for Which Melatonin Is Effective?

  1. Sleep disorders comprise of:

  2. Insomnia.

  3. Obstructive sleep apnea syndrome (OSAS).

  4. Hypersomnolence (excessive daytime sleep).

  5. Circadian rhythm disorders.

  6. Parasomnias (abnormal behavior during sleep).

  7. Sleep-related movement disorders.

However, synthetic melatonin is approved for the management of the following conditions:

  • Primary Insomnia: Primary insomnia does not occur due to an underlying condition. It is an inherent disorder. Primary insomnia remains for many years in a person’s life. It often begins during childhood. People experience a complete lack of sleep or problems falling asleep in this disorder. It is the most frequent type of sleep disorder. Patients experience irritability, frustration, daytime laziness, low energy, physical discomfort, and impaired mental functioning. Research suggests that melatonin can reduce the time it takes a person to fall asleep. But its effects on sleep quality and sleep time are unclear.
  • Age-related Insomnia: Aging changes sleep regulation in many individuals. Furthermore, melatonin production decreases with age. About 30 percent of people over age 50 experience insomnia. As a result, they have decreased total nighttime sleep time, frequent awakenings, difficulty falling back asleep, and early morning awakenings. These changes are associated with increased daytime sleepiness, attention deficits, memory deficits, and mood disorders. A study suggested that 300 micrograms (µg) of melatonin given to elderly insomniacs half an hour before bedtime could improve their sleep.
  • Jet Lag: Jet lag affects people while traveling across multiple time zones by airplane. People may not feel well and have disturbed sleep, daytime tiredness, impaired functioning, and digestive issues. Evidence suggests that melatonin can improve jet lag symptoms like alertness and daytime sleepiness. Melatonin is effective in preventing jet lag. Occasional short‐term use appears to be safe. It can be given to adult travelers flying across five or more time zones. Furthermore, it is recommended for recurrent jet lag. Various studies show that melatonin is effective in reducing jet lag. However, there is insufficient evidence to prove that melatonin improves sleep quality in jet lag patients.
  • Delayed Sleep-Wake Phase Sleep Disorder (DSWPD): The sleep pattern in this disorder is delayed from a regular sleep pattern. It causes a person to fall asleep late at night and wake up later. Research shows that melatonin reduces the time it takes to fall asleep. It further advances the sleep initiation in adults and children with DSWPD. However, it is uncertain about the risk-benefit ratio of melatonin in these patients.
  • Circadian Rhythm Sleep Disorders in the Blind: Studies reveal that there is less melatonin production in blind individuals. Furthermore, the eye lesions disrupt the biological clock in the daytime or nighttime environment. Assessment of sleep patterns in blind people shows a higher sleep disorder prevalence. In some studies, melatonin has been administered to blind subjects and compared with placebo (or no-treatment baseline). As a result, sleep parameters improve. The results suggest that prior knowledge of circadian rhythm and the timing of treatment may improve the efficacy of melatonin. Hence, melatonin can improve circadian rhythm sleep disorders in adults and children. Daily administration of synthetic melatonin is the current treatment of choice for this disorder. Melatonin is shown to rectify the underlying circadian rhythm abnormality. Also, it may improve sleep and decrease daytime napping.
  • Shift Work Sleep Disorder (SWSD): Disturbed sleep and sleepiness during the job are common problems among night shift workers. Synthetic melatonin is a promising treatment option for improving daytime sleep in night workers. However, it is unknown whether melatonin can improve daytime sleep quality and duration in people with night-shift jobs.
  • Pediatric Sleep Disturbances: Sleepiness in children may manifest as irritability, behavioral issues, learning difficulties, road traffic accidents (in teenagers), and poor educational performance. A majority of children with pediatric sleep disturbances respond to melatonin. A dose of one to three milligrams (mg) is given thirty minutes before bedtime. It can improve sleep onset and total sleep duration in about 80 percent of cases. Further, melatonin is well tolerated and has minimal adverse effects. However, it is recommended that parents work closely with the pediatrician before administering melatonin supplements to their children.

Oral melatonin in appropriate amounts is safe. However, side effects of melatonin include:

  • Headaches.

  • Giddiness.

  • Nausea.

  • Drowsiness.

Less common side effects include:

  • Mild depression.

  • Tremors.

  • Anxiety.

  • Abdominal pain.

  • Irritability.

  • Confusion.

  • Disorientation.

It can also cause mild daytime drowsiness. Hence, driving or using heavy machinery is not recommended within five hours of taking melatonin. The evidence regarding melatonin as a long-term drug for sleep disorders is limited. It is mainly due to poor bioavailability, rapid metabolism, and a short half-life. To know the efficacy of melatonin in treating sleep disorders, it is important to monitor the drug after administration. Furthermore, monitoring includes adverse drug reactions such as daytime sleepiness and headaches.


Insomnia is a common complaint seen in many patients. It is a safe first-line sleep aid that may promote a regular sleep cycle. As a result, many patients take melatonin as an OTC drug. However, clinicians recommend melatonin only for insomnia and jet lag disorders. Further, if a patient with insomnia does not respond to melatonin therapy, the patient should be evaluated by a psychiatrist for underlying disorders.

Frequently Asked Questions


Can Melatonin Cause Difficulty in Waking Up?

Melatonin typically does not cause difficulty waking up; it often enhances sleep quality. However, individual responses vary. If too much melatonin is taken or the body does not metabolize it efficiently, grogginess might occur. Using melatonin responsibly is crucial, considering factors like dosage and personal tolerance.


Does Melatonin Induce Sleepiness the Following Day?

Melatonin generally does not induce sleepiness when taken at the appropriate dosage and timing the following day. Its short half-life minimizes daytime effects. However, individual responses differ; excessive melatonin or improper use may lead to residual drowsiness. Using melatonin cautiously is advisable; consult a healthcare professional if concerns arise.


What Is the Elimination Time for Melatonin in Children?

The elimination time for melatonin in children varies but is approximately three to four hours. Age, metabolism, and dosage influence how quickly melatonin exits the system. Monitoring individual responses and consulting with a healthcare professional can help determine suitable timing for melatonin administration in children.


Is It Safe to Administer Melatonin to Children at Night?

Administering melatonin to children nightly should be approached with caution and under the guidance of a healthcare professional. While short-term use may be safe for certain conditions, prolonged or regular usage requires careful consideration of potential side effects and impacts on natural sleep regulation. Consultation with a healthcare provider is essential.


How Soon Does Melatonin’s Effects Dissipate?

Due to its short half-life, Melatonin's effects typically dissipate within a few hours after administration. The duration can vary based on factors like individual metabolism and dosage. Short-term sleep support is common, but the quick clearance from the body minimizes lingering effects, allowing for a more natural waking state.


What Is the Recommended Melatonin Dosage for Children?

The recommended melatonin dosage for children varies; it is crucial to consult a healthcare professional. Generally, lower doses ranging from 0.5 to 3 mg are considered appropriate. Individual factors such as age, weight, and specific sleep issues should be considered to determine the most suitable dosage for a child.


Is Melatonin Considered a Sleep Aid?

Yes, melatonin is considered a sleep aid. It is a hormone naturally produced by the pineal gland, and its supplement form is commonly used to regulate sleep-wake cycles. Melatonin supplements are often utilized to address sleep disorders or jet lag, helping induce sleep and improve overall sleep quality in some individuals.


Does Melatonin Have Cognitive Benefits?

While melatonin primarily regulates sleep-wake cycles, some studies suggest potential cognitive benefits. It may have antioxidant and neuroprotective properties, influencing cognitive function. However, more research is needed to establish conclusive evidence regarding melatonin's direct cognitive effects. It is primarily recognized for its role in sleep regulation.


How Quickly Does Melatonin Take Effect?

Melatonin's onset of action varies among individuals, but it typically takes effect within 30 minutes to an hour after administration. Factors such as dosage, individual sensitivity, and food in the stomach can influence the speed at which melatonin induces its sleep-promoting effects.


Who Should Avoid Melatonin Supplementation?

Individuals with certain medical conditions, pregnant or breastfeeding women, and those taking specific medications should consult a healthcare professional before using melatonin. People with allergies or sensitivities to melatonin or its components should also avoid supplementation. It is crucial to seek personalized advice to ensure safety and efficacy.


What Are the Effects of Melatonin on the Body?

Melatonin primarily regulates the sleep-wake cycle by signaling the body to prepare for sleep. It influences circadian rhythms and has antioxidant properties. Some research suggests potential immune function and neuroprotection benefits, although more studies are needed. Melatonin plays a vital role in sleep regulation and may have broader physiological effects.


How Rapidly Does Melatonin Produce Its Sleep-Inducing Effects?

Melatonin's sleep-inducing effects usually manifest within 30 minutes to an hour after administration. However, individual responses vary, and factors such as dosage, formulation, and personal sensitivity can influence the speed at which melatonin induces drowsiness, helping individuals transition into a more relaxed and sleep-ready state.


When Is It Too Late to Take Melatonin?

The ideal time to take melatonin varies, but 30 minutes to an hour before bedtime is recommended. Taking it too late may result in difficulty waking up the next day. Tailoring the timing to individual sleep patterns and consulting with a healthcare professional helps optimize melatonin's effectiveness while avoiding potential drawbacks.


Can Nightly Melatonin Use Be Harmful?

Nightly melatonin use can be generally safe for short durations, but long-term effects are not well-established. Potential side effects may include headaches, dizziness, or mood changes. It is essential to use melatonin under medical guidance, especially for extended periods, to monitor for adverse effects and ensure overall well-being.


Does Melatonin Pose Risks to the Liver or Kidneys?

Limited evidence suggests melatonin is generally safe for the liver and kidneys. However, individuals with pre-existing liver or kidney conditions should exercise caution and consult with a healthcare professional before using melatonin regularly. Monitoring liver and kidney function during melatonin supplementation is advisable to ensure safety for those with underlying health concerns.
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Dr. Basuki Nath Bhagat
Dr. Basuki Nath Bhagat

Family Physician


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