Three daycare workers were arrested in Illinois after allegedly admitting to giving their class of 2-year-olds melatonin-laced gummy bears to help them fall asleep at naptime, CBS Chicago reported. The sleep supplements were reportedly given to kids without parents being informed.

From a 120 gummy bottle, only four were left.

"This is just a horrible case of bad judgment," Des Plaines Police Chief William Kushner told CBS Chicago.

There are a number of reasons why this is a terrible idea, aside from the obvious (and potentially criminal) component of the story, which is that you don't give kids drugs or supplements without their parents permission.

There are also reasons to question whether or not supplemental melatonin is a safe or effective sleep aid for adults. Regardless of the answer, that doesn't make it safe for kids – and even if it was, it wouldn't make sense to give it at naptime.

The science behind melatonin

Melatonin is a hormone naturally produced by the brain. In our bodies, it helps regulate our sleep cycle. In a healthy person, the brain will start to release melatonin a short time before sleep, though bright artificial light from screens can convince the brain it's daytime and delay that hormone release.

Provided you haven't recently changed time zones (or gone through daylight savings time) and keep a regular schedule, it should naturally happen around the same time every night.

An artificial formulation of that hormone is often marketed as a sleep aid – and apparently, it comes in gummy form, too.

Plenty of adults take melatonin – some regularly, others while trying to adapt to new time zones.

  • There's a lot of debate about whether or not melatonin works for adults.
    Some studies show that it's more effective than others, with most showing that at best, it might help people fall asleep a few minutes earlier. But most people see a placebo effect, as UC Berkeley neuroscience and psychology professor Matthew Walker explains in his recent book, "Why We Sleep: Unlocking the Power of Sleep and Dreams."
  • If it works, it's probably most effective when you are dealing with jet lag, and it's probably only good in the short term.
    That's because the "problem" that's being solved, in theory, is that you want that hormonal clue that it's bedtime. If you've changed time zones, your body clock needs to adapt, and that clue might be helpful. But it doesn't mean you need it on a regular basis.
  • It's probably not effective long term.
    As clinical psychologist and NYC Sleep Doctor founder Dr. Janet Kennedy told Business Insider, if you were to regularly take melatonin (every night), your body would adapt and those supplements wouldn't do much for you.
  • We have no idea what's in most melatonin pills.
    The supplement industry is almost entirely unregulated and all kinds of ingredients have been found in supplements, some harmful. Studies have shown that the amount of "melatonin" in supplements could be none at all, or could be almost five times what's on the label.
  • What's safe for adults isn't always safe and doesn't always work for kids.
    There's little data on melatonin and children. There is some research indicating that short term melatonin use is probably safe for kids with ADHD or autism spectrum disorders and that melatonin can help those kids fall asleep a little more quickly. However, most data shows it probably doesn't change sleep time for kids without those diagnoses.
  • Naptime wouldn't be the right time to give kids melatonin anyway.
    The whole point of natural melatonin production is to cue your body clock in to the fact that night has begun and you need to sleep. Naptime is not night time and it doesn't have the same circadian (body clock) cues. If anything, those daycare workers could have messed up bedtimes for the kids, if their bodies thought biological night had already happened that day.

The daycare workers reportedly told local police that they thought what they were doing was harmless, since melatonin is sold over the counter.

But over the counter supplements like St. John's wort have been known to interact dangerously with drugs meant to treat serious conditions.

And in general, just because something is sold over the counter, it doesn't mean it's safe to take it at any time – the active ingredient in Tylenol kills about 150 Americans every yearand sends up to 80,000 people to the ER in the US every year.

You can't give kids supplements or drugs without talking to their parents – even if you think, mistakenly, that they are harmless.

This article was originally published by Business Insider.

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