The American Academy of Sleep Medicine has initiated an investigation into the safety of melatonin, which is increasingly used as a solution for chronic insomnia.

The body produces this potent hormone naturally from the pineal gland in large volumes at night to signal that it is time to sleep and at lower levels during the daylight hours.

The concern is not only whether high amounts of melatonin might be harmful, but also whether they might have an unfavorable effect on blood sugar, blood vessels, body temperature, and other physiological functions.

Melatonin is available OTC, often in the form of fruit-flavored gummy chews. In addition to having varied and unregulated levels of melatonin, OTC products often contain serotonin or unknown byproducts whose effect in this setting are uncertain. Melatonin may be safe over the short term, according to researchers, but is more questionable over the long term—particularly as it relates to potential disruption of puberty in pediatric users.

With so many unknowns, FDA will probably need to regulate melatonin as a medication, according to Muhammad Adeel Rishi, MD, vice chair of the academy’s Public Safety Committee.

In the meantime, the academy recommends that both children and adults refrain from using melatonin as a sleep aid while its investigaton is being conducted.