Parents may be accidentally overdosing their kids with mislabeled melatonin, lawsuit alleges

• A lawsuit filed in California alleges that a bottle of Zarbee's melatonin gummies contained twice the listed dosage.
• The Children's Sleep gummies were meant to contain 1 mg of melatonin a piece.

Melatonin overdoses in children are on the rise, and one lawsuit filed in California has alleged that inaccurate labels are to blame.

Krystal Lopez, a mother in Salinas, California, purchased a bottle of Zarbee's Children's Sleep with Melatonin gummies for her 8-year-old child this June, according to the suit. The gummies were meant to contain 1 milligram of melatonin a piece, but the suit alleges that the true melatonin content was more than twice the amount listed on the label.

For reasons not disclosed in the lawsuit, Lopez had the gummies tested at a university laboratory to determine how much melatonin was actually in the bottle she purchased. The lab also tested at least one other bottle from a separate lot, according to results summarized in the suit.

The gummies in Lopez's bottle contained 2.13 mg of melatonin on average, the suit alleges. Another bottle was found to contain 1.29 mg of melatonin per gummy — a marginal increase from the 1 mg listed on the label.

The suit, filed by law firm Dovel & Luner, claims that Zarbee's has "serious and systematic problems with its dosing and labelling [sic]," and that Lopez and other consumers would not have purchased the gummies had they known the product was mislabeled.

Melatonin use is relatively unregulated in the US

People naturally produce melatonin to trigger sleepiness in response to darkness, according to the National Institutes of Health. The hormone is essentially to maintaining a circadian rhythm, and some people may take supplements of it to get their sleep schedule on track while traveling or managing a sleep disorder.

The US Food and Drug Administration considers melatonin a dietary supplement, meaning anyone can take it at their own discretion. Doctors don't recommend melatonin to treat insomnia, as there's not enough evidence on the effectiveness or safety of melatonin supplements.

Melatonin supplements have come under scrutiny for mislabeling in the past. In 2017, researchers in Canada tested 31 different supplements and found that most did not contain the amount of melatonin listed on the label. About a quarter of samples were found to contain serotonin, an entirely different neurohormone, according to results published in Journal of Clinical Sleep Medicine.

Taking too much melatonin can cause unwanted side effects including excessive drowsiness, agitation, headache, and nausea, according to the National Poison Control Center. A melatonin overdose is not significantly toxic in the short term, and effects typically wear off after a few hours and a nap.

Zarbee's did not immediately respond to Insider's request for comment.