In my webinars, I talk a lot about the importance of sleep. A participant recently asked if melatonin might help alleviate her chronic insomnia. This was such a good question that I decided to create a blog about it. To understand the answer, it’s important to understand what makes us sleepy in the first place.

Why We Feel the Need to Sleep

There are two forces at work that make us want to sleep. The first is a chemical called adenosine which builds up in the bloodstream during the day. As it increases, we feel a greater need for sleep. Stimulants like caffeine will temporarily block the affects of adenosine, so we don’t feel as sleepy – at least for a while.

The second is our circadian rhythm, which regulates our sleep/wake cycle and repeats about every 24 hours. Melatonin is a hormone our bodies produce to regulate this sleep/wake cycle. It is produced in response to darkness. If you go about your activities during a normal day, this combination of adenosine and melatonin work just fine, as the adenosine is at its peak at roughly the same time it is getting dark.

The Circadian Rhythm Gone Awry

If you do shift work or travel across multiple time zones, your circadian rhythm gets out of whack. It isn’t dark when it is supposed to be dark, so your body doesn’t produce melatonin. In this case, taking melatonin as a supplement may be helpful. The pill sends a signal to the body that “it’s dark” even if it is light outside. The timing of this supplement is important. If you’re flying east, and trying to reset you body clock to an earlier time, take melatonin at local bedtime until you adapt to the new time zone. If you’re flying west and need to reset your body clock to a later time, take melatonin in the morning. (Granted, we’re not traveling as much in the pandemic but this may be useful when we start getting on planes again!)

Melantonin and Chronic Insomnia

There is less solid research about taking melatonin for insomnia. Both the American Academy of Sleep Medicine (2017) and the American College of Physicians (2016) say there is not enough strong evidence about the effect of melatonin supplementation to suggest its use for chronic insomnia. In addition, since melatonin is a dietary suppolement and not a drug, it does not have to adhere to the FDA quality control regulations. One study found that the actual amount of melatonin in supplements varied widely, from 83 percent less to 478 percent more than what the label indicated (1).

Melatonin May Have Side Effects

About 20% of people who take melatonin say that it causes daytime drowsiness. It can also have adverse affects when taken with other medications, including those for birth control, blood thinning and diabetes. Always talk with your doctor if you plan to take any supplements.

The Top Takeaway

Melatonin can be useful if you’re traveling across multiple time zones, but research doesn’t warrant taking it for chronic insomnia. In a future Smart Bite, I’ll write more about the latest evidence-based approach for treating chronic insomnia: CBT-I (cognititive behavioral therapy for insomnia).