In an article by CNN, a study recognized how more and more adults are taking OTC melatonin to sleep. Sleep specialist Rebecca Robbins, an instructor in the sleep division at Harvard Medical School, said that the study documented a significant increase in melatonin consumption in the past few years. By 2018, Americans involved in the study had doubled their melatonin intake from the previous decade. 

Experts hypothesized that COVID increased adult reliance on melatonin for sleep. Melatonin has been linked to headaches, dizziness, mild anxiety, depression, and tremors. It has also been linked to abnormally low blood pressure. While short-term usage seems to be safe, the National Center for Complementary and Integrative Health states that the side effects of long-term melatonin consumption are unknown. 

Since 2006, adults have been known to more commonly exceed the 5mg a day dosage typically used for treatment. This is partly because melatonin is not regulated by the FDA, so there are no federal requirements surrounding melatonin advertisement. Previous research reported that unregulated, commercially available melatonin supplements had a range from -83% to +478% their advertised content, according to Rebecca Robbins. Robbins then went on to state how no one can be sure of the purity of melatonin supplements, and that 26% of supplements have been shown to contain serotonin. Serotonin is a hormone that is harmful at low levels – more to read on that here. 

So melatonin consumption can be dangerous for adults. But what are its effects on kids? Another “Melatonin for Children: Experts say to use Caution” by Sandee LaMotte reported that there are uncertainties about what dosage should be used for children, and when that dosage should be administered. The National Center for Complementary and Integrative Health warns that melatonin supplements could affect hormonal development, including puberty, menstrual cycles, and prolactin overproduction (prolactin causes breast and milk development in women). 

Interestingly, in the original studies done in the 1980s 0.5-1.0 mg was shown to be an effective dosage. Now, companies are selling dosages of 5-200 mg. 

The timing recommended for all patient melatonin consumption is 2 hours before bedtime. It is also recommended to take children off melatonin for 6 weeks every 3-6 months to ensure that children’s bodies are still naturally producing melatonin. 

In children diagnosed with autism or ADHD, Dr. Cora Collette Breuner notes how melatonin has been highly effective at helping them fall asleep. However, it also states that in most children, decreasing screen time before bed may be an equally effective alternative to taking melatonin supplements. 

It seems that in children and adults, melatonin is still an experimental drug. The dosages are largely unregulated, and while the hormone does work at helping patients fall asleep, its long-term side effects are largely unknown. The difference between melatonin treatment for adults and children is dosage – but otherwise, treatment is the same. The difference in concerns are for puberty in children, and the way melatonin might affect growth. I would be curious to understand how the FDA decides which drugs to regulate, and which to not – as well as how healthcare providers are working with patients consistently taking melatonin over long periods of time.