Melatonin Supplements: Do They Benefit People With RLS?

Melatonin remains one of the most popular over-the-counter sleep aids. It’s inexpensive and doesn’t require a prescription.¹

But will it benefit a person with restless legs syndrome (RLS)? Are there other sleep disorders that benefit from using melatonin?

What is melatonin?

Melatonin, popularly known as the “sleep hormone,” regulates our wake-to-sleep transition nightly. It’s a major player in our circadian rhythms.

Circadian rhythms, when supported and functioning correctly, help us maintain balances across all of our biological systems (respiratory, endocrine, skeletal, digestive, neurological, and more).

It’s when our circadian system (you might think of it as the “body clock”) falls out of balance itself that we struggle with disease, discomfort, and problems with things like mood regulation, physical performance, decision making, and sleep.

Melatonin comes in two forms

Endogenous

The brain naturally generates this form of melatonin. The pineal gland manufactures it, then disperses it throughout the bloodstream, relying upon a series of time cues that include light exposure, eating schedule, and activity level.

Exogenous

This manmade form of melatonin can be taken orally. People usually take it in pill or capsule form. Melatonin-enhanced supplements eaten or consumed as beverages also exist. Some foods also contain melatonin, such as tart cherries, kiwifruit, malted milk, nuts, rice, and salmon.²

The key thing to remember here: Melatonin’s chief job is to support circadian rhythms. This means that only a few sleep problems are supported by melatonin supplements.

Does melatonin help treat restless legs syndrome (RLS)?

No. In fact, taking melatonin supplements may actually make RLS worse!

Some sleep disorders — specifically, circadian rhythm sleep disorders — are naturally linked to imbalanced levels of melatonin in the body. However, RLS isn’t a circadian rhythm sleep disorder. Instead, it’s considered both a movement disorder of sleep and a nervous system disorder.

This distinction matters from a body chemistry perspective.

The dopamine link

Melatonin, by its very nature, works to slow the release of another hormone, dopamine. Dopamine is associated with wakefulness.

This matters because deficient levels of iron in the blood, a known contributor to RLS, may disrupt the brain’s melatonin and dopamine levels. At bedtime, an imbalance of these two hormones - too much melatonin, too little dopamine - will likely worsen RLS symptoms.³ Ultimately, a melatonin supplement taken by someone with RLS comes with a higher risk for bedtime symptoms.

Let your sleep doctor know if you’re taking melatonin for any other reason. It will better inform them when it comes to your treatments for RLS and other health conditions.

Melatonin's best uses

Researchers still don’t fully understand how melatonin works. Its function and value in our overall health and wellness needs further research. In regard to sleep disorders, scientific understanding of the “sleep hormone” is similarly unclear.

As mentioned previously, circadian rhythm sleep disorders are the only category of sleep disorders that clearly benefit from melatonin supplementation.¹ Those sleep disorders include:

• Delayed Sleep-Wake Phase Disorder (DSWPD): A sleep condition in which people simply cannot fall asleep until extremely later into the night or early morning (such as a 2 am bedtime)
• Jet lag: A common temporary circadian rhythm imbalance caused by traveling quickly across multiple time zones
• Shift work disorder: Sleep problems caused by working late, night, or overnight shifts

In these cases, melatonin supplementation can help “reset” one’s circadian rhythms to a more normal and sustainable pattern.

What about insomnia?

One of the most common uses for melatonin is to offset sleepless nights. People with insomnia either struggle to fall asleep, stay asleep, or awaken far too early in the morning. However, the jury remains out on the benefits of using melatonin in adults who struggle with sleeplessness.

According to the National Sleep Foundation, some researchers “find some evidence in favor of melatonin, while organizations like the American Academy of Sleep Medicine (AASM) have concluded that there is not sufficient scientific support for melatonin in reducing insomnia.”^1,4,5

Melatonin also has side effects like headaches, dizziness, and nausea, and it can also interact with other medications, such as diabetes medications, contraceptives, immune system suppressants, and more.⁶