Melatonin has become widely used for people of all ages to help them fall asleep. And most people would likely sing its praises — especially those who have been able to get a better night’s rest after using it on their children. We’re not saying anyone is wrong — it’s over the counter and usually safe in the recommended doses, but there are definitely things to pay attention to when using the sleep aid. According to Consumer Reports , 86% of people who said they tried a dietary supplement for sleep chose melatonin as their remedy of choice. And about 25% of people who tried it said they got great sleep. But — you knew there was going to be a but, didn’t you? — though melatonin certainly has its uses, it’s important that it is used on limited terms. [READ NEXT: "This year may be worse than usual," doctor says of flu season | Distracted, moody, forgetful? Here's what might be wrong -- and how to fix it | How does age play a role in breast cancer risk? ] “Melatonin has an incredible safety record, no doubt about it,” Dr. Mark Moyad, the Jenkins/Pomkempner director of preventive and alternative medicine at the University of Michigan, told TIME . “But it’s a hormone, and you don’t want to mess around with hormones until you know what they’re doing.” Young women who want to become pregnant or mothers who are breastfeeding should not use melatonin, Medical News Today says , because it might affect the reproductive system. Another reason doctors may not openly give a full endorsement of melatonin is that some studies have shown that it may interfere with glucose regulation in people who have diabetes and carry certain genetics traits. Melatonin may increase seizures in people with seizure disorders, worsen bleeding disorders or symptoms of depression and interact with a slew of other people and medications. 💊View a list of 57 medications that interact with melatonin 💊 Moyad said his advice is to treat supplements like drugs, so don’t take a pill unless you need it. Simply put, use restraint with melatonin because of the lack of evidence proving it to be safe in high doses over long periods. He especially cautioned parents who give melatonin to their healthy children, mostly because of the lack of unknowns. Do you know the recommended dosage? Michael Grandner, the director of the Sleep and Health Research Program at the University of Arizona, said “anything between 0.5 mg and 5 mg.” That seems like a fairly large range, but he recommended a 0.5 mg dose, when used for repeated sleep-cycle regulation, be taken three to five hours before bedtime. Taking a 5 mg dose should be done by those wanting to take it right before bed.