The problem with natural sleep aids

When faced with sleepless nights, many people swear by supplements like melatonin and magnesium, herbs like valerian root, and drinks like tart cherry juice. But can these so-called natural sleep aids actually help you fall and stay asleep?

According to the National Academy of Medicine, 50 to 70 million people in the United States face chronic sleep issues—and collectively, Americans spend nearly $700 million dollars on sleep aids every year. Despite a growing global market for natural sleep aids, they likely do little to help.

Experts agree that sleep supplements don’t combat what’s at the root of insomnia: anxiety. “Insomnia is a medical condition,” says Michael Grandner, a clinical psychologist and director of the Sleep and Health Research Program at the University of Arizona. By definition, “supplements don’t treat medical conditions,” he says.

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There’s also little scientific evidence that supplements help people get shut-eye. Very few high-quality studies have tested how well they work, Grandner explains, while those that do carefully analyze sleep aids often show they induce no or only subtle changes in sleep quality.

Janet Cheung, a senior lecturer in pharmacy practice at the School of Pharmacy, University of Sydney, cautions that people should talk to their doctors before they try out any sleep aids. “Some people should not be taking these supplements, particularly pregnant women,” she says. That’s because we don’t yet know how these supplements might affect people from certain groups, like pregnant people and children.

But that doesn’t necessarily mean sleep aids don’t do anything. After all, people must at least believe they’re getting some benefit after spending hundreds of dollars a year on them. Here’s what the science says about popular natural sleep supplements—and which ones might work better than others:

Chamomile

Chamomile refers to many different plants in the Asteraceae family and is an ancient medicinal herb. Despite its popularity, studies on chamomile’s impact on sleep show mixed results. For example, one randomized controlled trial suggested that chamomile improved sleep quality in elderly people, but another study on people with insomnia found that it had no effect.

What might be behind these contradictory results? Part of it is the placebo effect: Any substance can have a strong placebo effect when it comes to sleep. In fact, any bedtime ritual can help you fall asleep faster, says Chris Winter, a sleep specialist, neurologist, and host of the Sleep Unplugged podcast.

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“Every time you take that shower or read that book or watch that television show right before bed, if you do it on a set schedule, your brain starts to recognize that this means you’re getting close to sleeping,” Winter says. And that’s also true with sleep aids—the act of taking a supplement may do more to signal to your brain that it’s time to sleep than the supplement itself. This effect is so strong that it’s very hard for researchers to show that sleep supplements are more effective than a placebo.

Moreover, Cheung points out that the main way people take chamomile is by drinking it in teas. “You’d have to drink a lot of chamomile tea to see some to reach the levels seen in randomized controlled studies.”

Melatonin

Melatonin is a hormone that regulates the sleep-wake cycle. Our brains churn it out when it’s dark in our environment, to signal to our bodies that it’s time to wind down.

There is some evidence that melatonin can help people with circadian misalignment fall asleep faster. Circadian misalignment happens when people’s natural sleep clocks aren’t matched up with their environment, and often affects shift workers and people with jet lag. Some studies also suggest it might also help people experiencing insomnia.

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But experts caution it should only be used on a short-term basis. Taking melatonin long-term could be detrimental because it causes the body to tamp down on natural melatonin production. In addition, experts argue that parents may want to think twice before giving their kids melatonin, as its long-term impacts in children have yet to be studied.

Winter stresses that people don’t need melatonin to fall asleep because ultimately it isn’t a sedative and doesn’t make us sleep. Instead, it signals to the rest of the body that it’s nighttime, putting the body in a state of rest, giving us more opportunities to fall asleep. Melatonin does little to quiet anxiety and the fear of not sleeping—which is what really keeps people up at night, Grandner explains.

“For most patients with insomnia, their bodies already know it’s nighttime, but they still can’t sleep,” Grandner adds. He and other experts agree that the most effective insomnia treatment is cognitive behavioral therapy, which Grandner says is “shockingly effective.”

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Tart cherry juice

Melatonin also comes in other forms, including the increasingly popular tart cherry juice, a beverage that is said to promote sleep and lower blood pressure. Tart cherries are high in natural melatonin so the juice might have similar effects to melatonin supplements. “They’re probably molecularly identical,” Grandner says. “If you had to choose between the two, I’d say take whatever makes you feel better. But I don’t think there’s a functional difference.”

Like other natural sleep aids, there’s not enough evidence to conclude that tart cherry juice significantly improves sleep, experts say. However, a few small studies show promising results. One randomized controlled study found that tart cherry juice mildly improved sleep quality in older adults, but the results were modest in comparison to interventions like cognitive behavioral therapy.

Magnesium

Magnesium is another molecule that plays an important role in many bodily functions, like vitamin D absorption. But there’s little evidence that magnesium supplements improve sleep. Only a small handful of large randomized controlled trials have tested magnesium’s effect on sleep, and systematic reviews of these studies have found that they are often of low quality and have conflicting results. In addition, most of these studies are in older adults, Grandner explains, so the results may not apply to everyone.

There’s more evidence that taking magnesium reduces mild anxiety and boosts mood, which might in turn help people sleep a bit better. But exactly how magnesium relieves anxiety is still unclear, and it likely won’t help people with severe anxiety.

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Grandner stresses that “the effect is usually very subtle.” For example, studies suggest that people taking magnesium fell asleep 17 minutes faster. “It’s not that huge of an effect, but it’s not nothing.”

Valerian root  

Valerian root is an herb native to Europe and parts of Asia and is a mild sedative. Studies investigating how valerian root influences sleep have had contradictory results. Some high-quality studies showed that it might help people fall asleep faster and feel like they’re sleeping better. However, other studies found that it has no effect on sleep quality and probably can’t treat insomnia, so more research is needed.

Cheung says we also know a bit more about what valerian root might do to the brain. Scientists hypothesize that it might increase the amount of gamma aminobutyric acid (GABA) in the brain. GABA is a neurotransmitter than generally tamps down neural activity and might relieve anxiety.

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CBD

Cannabidiol (CBD) is the non-psychoactive molecule found in cannabis. Unlike other potential sleep aids, CBD is known to work on the cannabinoid system, a complex messaging system throughout your body involved in regulating appetite, the immune system, and memory. Studies and reviews found evidence that CBD might decrease pain and anxiety, but its effects on sleep are still unclear.

Cheung is currently investigating whether over-the-counter cannabinoids can treat insomnia. “There’s a lot of research around the bidirectional relationship between sleep and pain and sleep and anxiety,” so relieving one might benefit the other, she says. But that also means it’s hard to disentangle cannabinoids’ sleep-promoting effects from their pain and stress relief effects.

If scientists do end up finding a connection, people who have trouble sleeping might have another tool in their arsenal. “This is a really exciting area of research,” Cheung says.