What happens when you take too much melatonin? – 12/25/2023 – Balance

Those who have never used their cell phones at bedtime raise their hands.

From checking the latest news to seeing the latest posts on social media, the device’s blue light is never far away.

The problem is that studies show that screen use has had a devastating impact on our sleep.

The reason is melatonin, a hormone produced in the pineal gland of the brain.

Melatonin plays a crucial role in regulating our body’s sleep and wake cycle and is sometimes called the “dark hormone” as its levels drop during the day but rise at night when sunlight disappears.

Anything that raises the level of light at bedtime — like the blue glow from electronic screens — can disrupt natural melatonin production and make it harder to sleep.

This helps explain why as many as one in three American adults are not getting the seven to eight hours of sleep a day that most people need.

It’s no surprise, then, that millions of people are turning to melatonin supplements to combat insomnia, the jet lag or difficulty sleeping after working late.

The hormone was released by Anvisa (National Health Surveillance Agency) in Brazil in 2022.

But among doctors, there is growing concern that melatonin is not as safe as marketing campaigns say.

During the Covid-19 pandemic, Michael Toce, a pediatrician in the emergency room at Boston Children’s Hospital in the United States, noticed an alarming trend: the number of children hospitalized for melatonin overdoses was skyrocketing.

“We see young children accidentally swallowing melatonin and teenagers who ingest it as a form of self-harm,” says Toce.

A 2022 study co-authored by Toce found that between 2012 and 2021, calls to report cases of melatonin overdose grew by 530%.

In 2020, American poison control services received more reports of childhood overdoses from melatonin than from any other substance.

The finding was reinforced by a June 2023 study, which identified that the number of children taken to the emergency room for melatonin overdose in the United States grew by 420% in a decade.

“The increase likely stems from increased use of melatonin,” says Toce.

“Melatonin sales have grown in recent years, as has pediatric use. Children become intoxicated by what is around them – so the increase in availability leads to an increase in intoxication.”

It is worth noting that the majority of children analyzed in both studies did not present any symptoms or only mild symptoms, such as stomach pain, vomiting or dizziness.

But in Toce’s larger study, which looked at 260,435 cases of melatonin ingestion, he identified nearly 300 cases of ICU admission. Five of them had to be intubated, and two died.

Melatonin has been implicated as a cause of other infant deaths as well. A 2019 study documented two separate cases involving a nine-month-old and a 13-month-old, both found passed out.

Toxicological tests at the autopsy of both showed high levels of melatonin – there were also traces of the substance in the cup used by the 13-month-old baby.

But in both deaths, there were factors that contributed to the tragic outcome: the first baby was sleeping in the same bed as an older sibling; and the second baby had been left in a warm room.

Both practices are factors that increase the risk of sudden infant death (SIDS).

There have been adverse effects in adults as well. A study from May this year reported the case of a 21-year-old woman who died from an overdose of melatonin and diphenhydramine, an antihistamine used to treat allergies, insomnia and cold symptoms.

In another case, a teenager experienced hypotension (severe low blood pressure) after attempting a melatonin overdose.

However, it is possible that these deaths or serious adverse effects were not directly caused by melatonin, but rather by another unrelated health problem.

Part of the problem is that, because the substance is classified as a supplement, it is not regulated by the US Food and Drug Administration, the FDA.

Melatonin has not undergone rigorous clinical testing, so there is no broad understanding of the hormone supplement’s impact on our bodies, nor how it interacts with other foods and supplements.

Furthermore, the dosage of melatonin in different products varies greatly.

“It’s like the Wild West,” says David Ray, professor of endocrinology and co-director of sleep and circadian neuroscience at Oxford University.

“Studies were carried out measuring the melatonin dosage of these products – and in none of the cases did the actual dosage match what was said on the packaging.”

It is not known what are the exact mechanisms by which melatonin could cause deaths or adverse reactions.

Studies in rats and mice indicate that melatonin has a toxic effect in extremely high doses (more than 400 mg per kilogram), but this is far more than the recommended dose (2 to 10 mg) for treating sleep problems.

What is known is that there are melatonin receptors throughout the body, including in the reproductive, cardiovascular and immune systems – but the substance’s effects outside the brain are little known.

At the same time, millions of people take melatonin daily without any adverse effects.

“All medications have side effects, so relative to other drugs used to treat sleep, it is considered very safe,” says Sanford Auerbach, professor and director of the Sleep Disorders Center at Boston Medical Center.

“However, I think what’s most concerning is the unknown. If you give (melatonin) to a developing child, what impact is that going to have ten years from now? We don’t know. We don’t even know how much melatonin is in excess, because such studies have simply never been done.”

Read the original version of this report (in English) on BBC Future website