What the Research Says About Popular Sleep Supplements
Published on October 17, 2023
Medically reviewed by Melissa Nieves, LND
Sleep is one of the most vital aspects of life, yet it doesn't always come easy. Without enough quality sleep, you may experience exhaustion, poor attention, trouble completing daily tasks, and even anxiety or depression.1
For centuries, scientists have researched numerous herbs, vitamins, minerals, and nutrients as potential sleep aids. And although not all supplements for sleep work, some do show promise.
This article will discuss the science behind several popular sleep supplements and how to properly use them, including any important precautions and side effects.
Getty Images / Dima Berlin
Using Supplements as Sleep Aids
If you've found that falling and staying asleep is difficult, you may be wondering about using supplements for sleep.
Over the years, sleep supplements have become a popular option for anyone having trouble getting sufficient sleep at night. However, there are some things to remember when using them.
Supplements must be used correctly and shouldn't be a first-line treatment for trouble sleeping. It's best to create healthy sleep habits before resorting to sleep supplements.
When it comes to improving your sleep, nothing beats healthy sleep hygiene, like getting enough physical activity during the day, avoiding large meals and caffeine before bed, and allowing yourself enough time for sleep each night.2
Supplements for sleep are classified as complementary treatments and should be used along with other measures that can benefit your sleep hygiene. Sleep supplements are sometimes used to treat sleep disorders, but having trouble sleeping doesn't always mean you have a sleep disorder.3
While some supplements may offer sleep benefits, not all are supported by strong scientific evidence. For this reason, it's important for you to talk with a healthcare provider about the safety and efficacy of any sleep supplement you plan to take.
Precautions: How to Safely Use Sleep Supplements
Safe supplement use reduces the risk of side effects or adverse events.4 As with other supplements, appropriate use is key.
In general, not much is known about the safety of sleep-promoting supplement products. Typically, using supplements comes with a risk of experiencing side effects.
Melatonin is one example of a commonly used supplement for sleep. Possible side effects of using melatonin in adults and children are:5
Unless otherwise directed by a healthcare provider, sleep supplements shouldn't be used for long durations. This is because there aren't enough long-term safety studies.
It's also important to avoid mixing sleep supplements or taking too much at once. Taking multiple sleep supplements at the same time may cause adverse events. And taking too much can lead to overdose in some situations.5
Sleep supplements may not be right for everyone. As an example, melatonin is not recommended for people with dementia, those who are pregnant or breastfeeding, and people taking certain medications.5 Other sleep supplements may require similar precautions, so talk with a healthcare provider first.
Dietary supplements are not regulated like drugs in the United States. They can cause interactions with medications or have other safety concerns. For this reason, it’s important to be aware of what to look for when choosing a supplement, such as third-party testing, potential drug interactions, and more.
Melatonin is a hormone that your body produces naturally. It is typically released in the evening as your brain reacts to the dark. In your body, melatonin helps regulate your circadian rhythms (24-hour cycles that follow the body's clock).6
Melatonin supplements are typically made from synthetic ingredients, but more natural options are available. While there is evidence that melatonin supplements may help with jet lag and certain sleep disorders, it's not necessarily a cure-all for all sleep problems.5
Clinical trials on melatonin have found that the supplement shows the most promise in people with sleep disorders that affect circadian rhythms. As such, melatonin may also help those with jet lag or who work late shifts fall asleep more easily.78
Research has also shown that melatonin may help people with insomnia fall asleep quicker, but it won't necessarily help them stay asleep.6 The American Academy of Sleep Medicine does not recommend melatonin to treat sleep onset or sleep maintenance insomnia, according to their 2017 clinical practice guidelines.9
Magnesium is one of the most abundant minerals in the human body. It's a vital part of numerous processes in your body and may even help you sleep.
Many studies have focused on the effects of magnesium supplementation on sleep.
A systematic review of clinical trials found that magnesium is associated with positive benefits for sleep in observational studies (based on information collected from participants) more often than in randomized controlled trials, which randomly assign people into either experimental or control groups (the gold standard for human research).10
According to the review, observational studies have found an association between higher magnesium intake and better sleep quality. Although results have been mixed, some randomized controlled trials have linked magnesium supplementation to improvements in sleep efficiency and sleep time.10
Another review concluded that although magnesium may be an affordable supplement option for those with insomnia, research on magnesium for sleep is weak.11 Stronger studies are needed in this area.
Lavender essential oil is commonly used in aromatherapy for stress, anxiety, and sleep disorders. Two compounds found in lavender, linalyl acetate and linalool, are thought to cause sedative effects by acting on the parasympathetic nervous system.12
Research on lavender as an aromatherapy has been somewhat lacking, as many of the studies in this area are small and short. Regardless, some studies have yielded positive results.
A study of 120 patients with cancer found that lavender aromatherapy improved sleep quality. Lavender was compared to a placebo and peppermint essential oil. By the end of the trial, participants who used either peppermint or lavender essential oils had lower scores based on the Pittsburgh Sleep Quality Inventory (PSQI), indicating they experienced better sleep quality.12
In another study, 79 college students were randomized to wear an inhalation patch while they slept for five nights. The patches contained either lavender essential oil or nothing (placebo). Along with practicing better sleep habits, those who used the lavender patches experienced more significant improvements in sleep quality than those who used the placebo patches.13
CBD oil was used in capsule form in one study on sleep conducted at a psychiatric clinic. Seventy-two patients completed the three-month study and used CBD oil in varying doses based on factors like medical history. CBD use was associated with sustained improvements in sleep throughout the study for most (but not all) participants.14
Overall, research results on CBD oil's effects on sleep are mixed, and many studies have been quite small. There is some evidence that CBD oil acts as a hypnotic, which may help with sleep problems. However, various studies have reported no significant effects of CBD oil on sleep parameters, like sleep quality.15
More vigorous research is needed to determine the role of CBD oil in sleep. Moreover, there are concerns about understanding the safety of CBD, including its drug interactions and potential for adverse effects.
Valerian is an herb that is most commonly used in alternative medicine to treat sleep issues like insomnia. Although, results from many sleep studies on valerian have been inconclusive.16
According to a systematic review from 2020, valerian has been used for centuries for its purported sedative and hypnotic effects. The researchers found it challenging to come to any solid conclusion regarding valerian's use in sleep disorders based on the human trials included in the review. However, the researchers determined valerian may be most helpful in treating simultaneous anxiety and insomnia.17
Due to the inconsistent results from studies on valerian, the American Academy of Sleep Medicine does not recommend using the herb for chronic insomnia.9 Valerian is thought to be safe for short-term use, though.16 It's best to talk with a healthcare provider before using valerian for sleep.
Several human trials have examined GABA supplements (like capsules) or GABA-enriched foods as possible treatments for poor sleep.
One review found only limited evidence that GABA supplementation improves sleep. While some research has shown that GABA reduces the time it takes to fall asleep (sleep latency), other studies have found GABA not to affect things like sleep efficiency, total REM (rapid eye movement) sleep, and overall time asleep. Researchers from the review felt that larger and better-designed studies are needed to learn more about the dosing, duration, and effectiveness of GABA on sleep.18
Chamomile is a medicinal plant often used in tea or as an extract for various health concerns. It is said to have a calming effect, which may be one reason why it has been researched as a possible solution for sleep problems.
A small study on older adults with poor sleep quality compared chamomile extract capsules to a placebo. Participants who took 400 milligrams (mg) of chamomile every day for 28 days experienced improvements in sleep quality. These improvements were found to be significantly better compared to the placebo group. However, higher-quality studies are needed to validate these findings.19
Likewise, a systematic review of 12 human trials concluded that chamomile supplementation may improve sleep quality. Chamomile use was also found to improve generalized anxiety disorder (GAD) in the studies included in the review. However, no significant effects were reported when it came to chamomile's effects on insomnia.20
An herb native to the Americas, passionflower has been used as a sedative by indigenous people for centuries. However, more research is needed on the use of passionflower for sleep.21
In vitro research (test tube studies) has found a link between passionflower and reduced sleep latency, as well as increased sleep duration. Passionflower is thought to act on GABA receptors.22 However, these effects have not been confirmed in humans.
A 2020 review mentioned very few studies that covered the role of passionflower in sleep disorders.23
In one small study, 41 young adults with mildly poor sleep quality were randomized to consume passionflower tea or a placebo tea every night before bed for one week. After keeping a sleep diary, it was determined that those who consumed passionflower tea had subjective improvements in their overall sleep quality.24
Most other studies on passionflower for sleep have used animal models rather than humans. This means that more research is necessary in this area before any definitive conclusions can be made.
After consumption, tryptophan is converted to a neurotransmitter thought to stimulate sedation (although this has not been fully proven). This neurotransmitter also plays a role in the secretion of melatonin.26
A meta-analysis reviewed 21 human studies on the effects of tryptophan on sleep. As a whole, tryptophan supplementation was associated with improved factors like sleep efficiency, sleep latency, and total sleep time. However, tryptophan was most helpful when used at a dose of at least 1 gram (g) per day, and some of its positive effects were not significant.26
Many people use supplements for sleep, but not all are worth the hype. While some nutrients, herbs, and other substances may help you fall asleep quicker and stay asleep longer, more research is needed to support most sleep supplements.
In terms of safety, sleep supplements should not be mixed and should not be taken with medications that may cause sleepiness. Additionally, sleep supplements should only be taken for a short time.
If you're interested in trying a new supplement for sleep, talk with a healthcare provider to learn more about safety, dosage, and which one is right for you.