Journal Club - Dubious role of Melatonin in Insomnia : JAMA study

Melatonin is the hormone that is pivotal in maintaining and regulating a person's circadian rhythm owing to which they are frequently used as an over-the-counter sleep medication.

Melatonin hormone is secreted by the pineal gland which is located at the back of the head. This hormone is found to demonstrate antioxidant and anti-inflammatory properties.

However, according to recent research published in JAMA Network, researchers have found adverse effects linked to high doses or long-term use.

The bigger problem is the variation and lack of uniformity in the composition of various over-the-counter melatonin medications which has prompted the researchers to delve deeper into the issue.

The researchers examined reported trends in the use of melatonin supplements among US adults from 1999 through 2018. The recommended dosage of melatonin normally does not exceed 5 mg/d. Therefore they evaluated the prevalence and trends in the use of greater than 5 mg/d of melatonin additionally.

As per reports, melatonin supplement consumption among adults in the US notably increased from 1999 to 2000 and then from 2017 to 2018 across various demographics. The trend of greater than 5mg/d use increased over time. These figures and estimates are concern worthy especially because the actual content of melatonin in the over-the-counter supplements maybe 470% more than what the label mentions. Also, the evidence which supports the use of melatonin in inducing sleep is quite weak.

The research had certain limitations like the inclusion of self-reported use of melatonin, although supplement containers were verified in almost all participants. Because of the small number of melatonin users in some subgroups, the results of stratified analyses should be interpreted with a grain of salt.