Key takeaways

Melatonin is a naturally occurring hormone that helps regulate sleep, but its production can be disrupted by exposure to light, leading some individuals to use supplements for sleep disorders or jet lag.
Taking too much melatonin can be harmful, with potential side effects including drowsiness, headache, nausea, and agitation, though it’s usually not lethal.
Melatonin supplements are not strictly regulated by the FDA, and there is no standard dosage, making it important to consult healthcare providers for safe consumption guidelines.
Children and adults can experience adverse effects from melatonin overdose, but severe toxicity is unlikely; however, in rare cases, excessive intake has led to hospitalization and very few reported deaths.

Maybe you’re one of the 50-70 million individuals in the United States with a sleep disorder. Maybe you just have difficulty falling asleep from time to time. Either way, you may have turned to melatonin to help you catch more zzz’s before trying a prescription medication or over-the-counter sleep aid.

Melatonin is a naturally occurring hormone that is produced by a tiny gland in the brain (called the pineal gland) that normally regulates the body’s sleep-wake cycle, or circadian rhythm, according to the Centers for Disease Control and Prevention (CDC). When sunlight gives way to darkness, the body is triggered to produce melatonin, which signals the body that it’s time to sleep. But if you’re exposed to light after sundown (that blue light from your phone counts, too), melatonin production is disrupted. That means melatonin levels don’t rise as they should, potentially resulting in difficulty falling asleep.

What’s more, some people with sleep problems have chronically low levels of melatonin. For these individuals, small doses of melatonin supplements may play an important role in helping them get a good night’s sleep.

Lab-produced, or synthetic, melatonin supplements can help with jet lag, delayed sleep-wake phase disorder (a condition in which people have a hard time falling asleep before 2 a.m. to 6 a.m.), certain childhood sleep disorders, and pre-surgery anxiety, according to the U.S. Department of Health and Human Services.

Although more research is needed, this supplement may be helpful for individuals with insomnia. There’s also some evidence that high doses of melatonin given to cancer patients in conjunction with treatment like chemotherapy may help shrink tumors and improve survival rates. But is it safe? Here’s what you need to know about the potential dangers of melatonin for sleep.

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Can you overdose on melatonin?

It is possible to overdose on melatonin. However, because there’s no standard dosage, the amount it takes to overdose is not well understood by experts. Since melatonin is a dietary supplement—not a medication—it’s not as strictly regulated by the U.S. Food and Drug Administration (FDA).

Melatonin formulations

The most common form of melatonin is a pill or tablet that can be taken orally with water before bedtime, says David Seitz, MD, board-certified physician and medical director of Ascendant Detox in New York. Products in liquid form offer quicker absorption and faster results, he says.

Melatonin is also available as lozenges and sprays, and in combination products, along with herbs (like valerian root and passionflower), says Kelly Johnson-Arbor, MD, a medical toxicology physician and co-medical director at National Capital Poison Center. Dietary supplements containing melatonin may be combined with cannabidiol (CBD), which some research indicates may be beneficial for sleep. Just check with your healthcare professional before using CBD if you haven’t used it before, to make sure it is safe for you to use.

Finally, melatonin comes in chewable tablets or gummies. Gummy supplements, a tasty and convenient formulation, are becoming increasingly popular among kids and those who have difficulty swallowing pills, Dr. Seitz says.

When not to take melatonin

Using melatonin is not a good idea for those with health conditions like autoimmune disorders or dementia, and individuals who are pregnant or breastfeeding. According to Dr. Seitz, melatonin may interact with certain medications—it’s not recommended for people with seizure disorders, those who are on blood thinners, or those undergoing surgery, due to the risk of serious side effects. It could also lower blood pressure, so those taking medication for hypertension should avoid melatonin because the combination could cause severely low blood pressure.

“It is also important to note that melatonin can have an effect on hormone levels, so it should not be taken if you are taking hormone-altering medications,” adds Dr. Seitz. That includes hormonal birth control and hormone replacement therapy.

How much melatonin is safe to take?

For children, the American Academy of Pediatrics suggests starting at the lowest possible amount of melatonin—0.5 to 1 milligram (mg)—about 30 to 90 minutes before bedtime, with a maximum dose of 3 mg for children and 5 mg for adolescents (ages 10-19 years). Parents should be sure to consult with their child’s pediatrician first to determine a safe dose of melatonin. Then, monitor your child for adverse effects after consumption.

Short-term use of melatonin is typically considered safe in healthy adults, says Nicole Roach, a registered dietitian at Lenox Hill Hospital New York. That said, long-term data on the safety of melatonin is lacking. There’s no official recommendation for adults, but 1-5 mg is generally considered a safe starting dose, with a maximum dose of 10 mg. Older adults should take the lowest dose of melatonin possible—some individuals may find that small doses (1 mg or less) can be effective.

“Taking too much melatonin can be dangerous,” Dr. Seitz says, “so it’s important to follow the dosage instructions on the product label.” Always talk to your doctor about the right dosage for you.

Melatonin is usually metabolized quickly, with a half-life of about one to two hours after it is ingested, says Dr. Seitz. However, the effects of melatonin can last up to 12 hours in some people, he says. It’s best not to drive or operate machinery within four to five hours of taking melatonin.

When taking melatonin, start low, increasing slowly as needed, and always consult your healthcare provider with questions on dosing. Don’t underestimate the power of sleep hygiene tips, like avoiding screen time in the bedroom

Symptoms of a melatonin overdose

Even with large doses of melatonin, significant toxicity is not likely to occur, according to the National Capital Poison Center. If an adult or child takes too much melatonin, wake them every 30 minutes until symptoms have resolved, and reach out to your healthcare provider for medical advice.

While it’s unlikely that taking melatonin will result in unconsciousness, some people may experience excessive drowsiness or abnormal behavior after taking it, says Dr. Johnson-Arbor. It’s important to watch out for dangerous side effects: If the individual is exhibiting breathing irregularities or can’t wake up after ingesting melatonin, call 911 or go to the nearest emergency room.

If you are concerned about accidental melatonin ingestion or overdose in yourself or your child, call the Poison Control at 800-222-1222 or use their online tool at poison.org, advises Dr. Johnson-Arbor. “Both options are free, confidential, and available 24 hours a day,” she says.

Remember that not all instances of melatonin use will result in side effects; they will often be mild, but may last for several hours. The most important thing you can do is monitor for severe side effects and seek medical attention if needed.

Melatonin side effects in children include:

Drowsiness
Bedwetting
Headache
Dizziness
Agitation

Adults may experience:

Headache
Dizziness
Nausea
Sleepiness
Anxiety
Depression

Can you die from melatonin?

According to a 2022 report, 260,435 cases of pediatric melatonin ingestion were reported to the American Association of Poison Control Centers from 2012-2021. Nearly 85% of children were asymptomatic, but some developed severe symptoms and required hospitalization. Two children (ages 3 months and 13 months) died. Still, melatonin overdose deaths are very rare, and there is no known lethal dose. As a precaution, keep melatonin—and all other medications—out of reach and out of sight of children and pets.

What to do if you think you’ve taken too much melatonin

The most common unwanted side effects from ingesting too much melatonin are sleepiness, headache, nausea, and agitation. If these or other worrisome signs and symptoms occur after taking melatonin, contact Poison Control for immediate expert and non-judgmental advice, Dr. Johnson-Arbor says.