What are the negative effects of melatonin?

It is safe to take melatonin supplements every night, but only for the short term. This is because less information is available about its long-term safety. Administering melatonin in children also needs caution. Kindly contact your health care provider or pediatrician for more advice.
Taking the recommended dose of melatonin may increase your blood melatonin levels up to 20 times more than normal and give you the following side effects:
- Excessive sleepiness
- Headache
- Dizziness
- Fatigue
- Irritability
- Stomach discomfort
- Anxiety
- Depression
It will be safer to use melatonin for a short time. Consult your doctor if you wish to continue taking it in the long term.
You can try shifting from melatonin supplements to other options like meditation, muscle relaxation, biofeedback therapy, and more for your sleep issues.
If you find yourself getting addicted to melatonin supplements or suffer from any of their side effects, you need to reach out to your doctor.
How long does it take for melatonin to kick in?
With the recommended dose of melatonin (1-3 mg), it takes around 1-2 hours to induce sleep. Hence, you should take melatonin supplements 2 hours before bedtime.
If you want to take melatonin to avoid getting jetlag, you need to start taking the pills a few days before you make your trip. Once you reach the new time zone, take the melatonin sleeping aid 2 hours before you go to bed.
What is melatonin?
Melatonin is a natural hormone that plays a role in your sleep-wake cycle. It is synthesized mainly by the pineal gland located in the brain.
Melatonin is released in response to darkness and is suppressed by light. As the sun goes down and darkness increases, the pineal gland begins to secrete melatonin, which usually happens after 9 p.m. The increased levels of melatonin in the blood send signals to the brain to become less alert and feel sleepy.
Melatonin secretion peaks in the middle of the night (between 2 and 4 in the morning) and decreases gradually during the second half of the night. Nearly 80% of melatonin is synthesized at night.
The production and secretion of melatonin start to go down in response to the sunlight. This makes you alert and wakes you up in the morning.
For people with sleep issues, melatonin is available as a sleeping aid supplement in the form of pills, liquids, and chewable.
Which foods contain melatonin?
Due to their melatonin content, the following foods and liquids could make you fall asleep faster and improve your sleep quality:
- Tomatoes
- Walnuts
- Almonds
- Olives
- Rice
- Barley
- Strawberries
- Cherries
- Cow's milk
- Bananas
- Pineapple
- Oranges

SLIDESHOW
Sleep Disorders: Foods That Help Sleep or Keep You Awake See SlideshowWhat conditions benefit from the use of melatonin supplements?
The following issues can benefit from taking melatonin supplements:
- Jetlag: Travelling across multiple time zones gives you jetlag and disturbs your sleep pattern.
- Shift work sleep disorder: Shift work disorder can be caused by working night shifts, rotating shifts, or even an early morning shift. This leads to sleep deprivation and the inability to fall asleep when you need to.
- Insomnia: Trouble falling asleep or staying asleep
- Delayed sleep phase disorder (DSPD): You cannot fall asleep fast, so you end up staying awake beyond midnight and find it difficult to wake up early in the morning when you need to.
Doctors have also recommended melatonin supplements for the following conditions:
- Sleep disorders and certain developmental and behavioral disorders in children
- Sleep disorders in adults with
- Alzheimer's disease
- Dementia
- Bipolar disorders
- Schizophrenia
- Depression
- Before and after surgery to reduce anxiety
Who can prescribe melatonin?
Melatonin is considered a dietary supplement. This means that it is regulated less strictly by FDA than a prescription or over-the-counter drug would be.
Melatonin is sometimes prescribed by the pediatrician for specific health or behavior conditions. The conditions include
- attention deficit hyperactivity disorder (ADHD) and insomnia,
- asthma,
- autism spectrum disorder, and
- atopic dermatitis.
In adults, melatonin may help those with jet lag.
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Is it bad to give your child melatonin every night?
Putting your child to sleep may be your favorite routine or your worst nightmare depending on your kid's inclination to sleep! Often, you are exhausted, your child refuses to sleep or sleeps fitfully through the night and you are tempted to give them something.
Many parents consider over-the-counter medications to help with their kid's 40 winks, but is that really a good idea? Most doctors do not agree, and their reasons are fair! Although doctors prescribe melatonin in kids who have insomnia along with autism spectrum disorder or attention deficit hyperactivity disorder (ADHD), melatonin should not be used in the following cases:
- Healthy children without sleep problems promote restful sleep
- Teenagers in an attempt to force sleep onset to accommodate early school start times
What are the side effects of giving melatonin to children?
Read on to find out why giving melatonin to an otherwise healthy child is a bad idea.
- Melatonin is a hormone (substance) produced by the brain's pineal gland. It is linked to the body's circadian rhythm (sleep/wake cycle). Melatonin release is stimulated by darkness and suppressed by light. The hormone was initially thought to be more important in lower animals. Only recently have we discovered the importance of melatonin in human behavior, sleep physiology, eating patterns, and mental health. In absence of clinical evidence of its entire spectrum, it is better to avoid the rampant administration of melatonin.
- Melatonin is sold as an over-the-counter sleep aid or supplement in the United States. Supplements are not regulated by the U.S. Food and Drug Administration (FDA). Therefore, the dosing and adverse event profile of melatonin are not widely studied. The natural origin of melatonin does not make it completely safe.
- Melatonin has a role in sexual maturity in lower animals. Whether it has a similar role in humans is yet uncertain. We do not know if and at what doses melatonin affects the ovaries and testicular function in teenagers and kids. The relationship between melatonin and human puberty is yet not proven or adequately studied. Hence, it is risky to administer.
- The long-term side effects of melatonin supplements in the body are uncertain. We do not know at what doses melatonin causes more side effects.
- The reliability of over-the-counter preparations is uncertain. These preparations may contain dangerous contaminants.
- We have few or no studies for melatonin in special populations such as those with insomnia along with anxiety, mood disorders, etc.
- Side effects of taking melatonin are daytime sleepiness, headaches, and giddiness. These may impair the child's school performance. Other rare side effects include abdominal pain, irritability, confusion, and depression. It is unknown how common or severe these side effects might be in children.
How do I put my teenager to sleep on time?
You can put your teenager to sleep on time in the following ways.
- Encourage healthy sleep habits such as a consistent sleep schedule even on weekends.
- Avoid daytime naps.
- Avoid TV, smartphone, and iPad at least an hour before bedtime. Blue light from tablets or monitors can disturb the body's endogenous melatonin cycle.
- Have dinner at least 2 hours before bedtime.
- Avoid food and drinks with caffeine after 6 p.m.
- Make sure the child's bed is comfortable, the room temperature is neither too warm nor too cold, and there is no noise near the bed.
If your child consistently has trouble falling asleep or staying asleep, call your pediatrician. Most sleep disturbances in children and adolescents can be managed with a fixed sleep schedule and behavioral therapy. In a limited number of cases, your child may need medications or supplements.
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Health Solutions From Our Sponsors
"Cases in CAM: Melatonin for a Natural Sleep: What's the Evidence?" <https://www.medscape.org/viewarticle/580248_2.>.
Owens, Judith A. "Pharmacotherapy for insomnia in children and adolescents: A rational approach." Dec. 19, 2022. UpToDate.com. <https://www.uptodate.com/contents/pharmacotherapy-for-insomnia-in-children-and-adolescents-a-rational-approach?search=melatonin%20use%20in%20kids&source=search_result&selectedTitle=1~113&usage_type=default&display_rank=1#H727571870>.
Suni, Eric. "The Best Foods to Help You Sleep." Sleep Foundation. Sept. 19, 2022. <https://www.sleepfoundation.org/articles/food-and-drink-promote-good-nights-sleep>.
Suni, Eric. "Melatonin and Sleep." Sleep Foundation. Oct. 7, 2022. <https://www.sleepfoundation.org/articles/melatonin-and-sleep>.
United States. "Melatonin: What You Need to Know." National Center for Complementary and Integrative Health. July 2022. <https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know>.
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