What Sleeping Aids Are Actually Effective? (Science-Based Review)

by Dale Cudmore | Updated: Sep 07, 2021

If you tell someone you’re having trouble sleeping, you get all sorts of suggestions (“have you tried garlic?”).

Like most things, everybody has an opinion on sleeping well, and not many have any scientific basis for their thoughts.

So in this post, I’m going to summarize the current literature on potential sleeping aids to see if there’s a reason to even give them a try.

Melatonin Supplements

Of every sleeping aid on this list, melatonin is by far the most studied.

Pretty much every study finds that melatonin has a positive effect on sleep for most people, with very little safety risk (1).

The most commonly found benefits of melatonin supplementation are (2, 3):

Decreased sleep onset latency (i.e. time it takes to fall asleep)
Increased overall sleep time
Improved sleep quality

But note that melatonin still has less of an effect than other proven insomnia treatments:

...the absolute benefit of melatonin compared to placebo is smaller than other pharmacological treatments for insomnia.

So while it can help with minor issues, the only times it might be prescribed for insomnia is when there’s a clear temporary cause like (4):

Jet lag from travel
Shift work
Circadian rhythm‐related sleep disorders

If you'd like a recommendation, see our review of the best melatonin supplements for insomnia.

Melatonin Safety Concerns

There hasn't been much research done on long term melatonin research. But research does indicate that it’s safe for most people in the short term (the only real concerns are drug interactions, allergies, or over using).

However, there’s a lot of “fake”, low quality melatonin supplements.

One study found that (5):

Melatonin content did not meet the label within a 10% margin of the label claim in more than 71% of supplements and an additional 26% were found to contain serotonin.

Unfortunately, the names of the brands are not included.

There was one chewable tablet that had almost 9 mg of melatonin (478% increase from label claim), which is a lot. Most research shows that a mg or two is enough.

On the other end, one supplement had only 17% of the melatonin it claimed.

A melatonin supplement that contains other substances could introduce new safety concerns.

So if you’re going to buy melatonin, maybe don’t opt for the cheapest ones.

See our full guide on how melatonin helps insomnia for more details.

SummaryMelatonin supplements have been heavily studied and are effective at improving sleep quality in many people who have poor sleep. However, research about long term usage is limited and users should keep in mind that the melatonin content of many over the counter products differs from label claims.

5-HTP (from Griffonia Seed)

Of every aid on this list, 5-HTP is probably the most overhyped.

The logic behind taking 5-HTP supplements is that 5-HTP is the immediate precursor to serotonin, which is an important neurotransmitter for sleep and mental health (i.e. serotonin levels are typically low in depressed people) (6).

Most studies about 5-HTP and serotonin focus on trying to treat depression, but some do look at the impact on sleep as well.

There’s a bunch of affiliate sites out there pushing 5-HTP as the solution to all depression and sleep issues, but research doesn’t quite back that up.

As one literature review states (7):

Under close examination, 5-HTP may be contraindicated for depression in some of the very patients for whom promoters of 5-HTP advocate its use.

One example cited is of a study that 5-HTP promoters often point to where 43% of depressed patients improved after taking it.

However, research has also shown that (8):

Double-blind, placebo-controlled studies of depression have consistently revealed that the placebo effect after 30 days of depression treatment ranges from 30%–45%.

Given the nature of the original study, the results are nothing necessarily greater than a placebo.

Some studies on 5-HTP do show some small significant positive impact, and some show a negative impact. It’s likely that it can be useful in a specific situation used in a specific way, but it doesn’t have the same broad effectiveness as something like melatonin.

Results Seen From 5-HTP Supplementation

While all the mechanisms aren’t clear, there is one path that demonstrates why 5-HTP can be counterproductive in high doses.

We know that low levels of serotonin are linked to depression and insomnia. When those levels are corrected, sleep does usually improve (9).

However, when 5-HTP is supplemented (alone), it outcompetes other precursors. This leads to depletion of other important monoamines, namely dopamine, which is going to have side effects that can worsen sleep or depression (10).

It may be possible to supplement 5-HTP along with something else to avoid this, but that hasn’t been researched thoroughly.

A safer way to increase 5-HTP without any side effects is simply exercise (11).

SummaryResearch supporting 5-HTP supplementation for improving sleep is sparse. It may help some people in specific situations, but it can also make sleep worse for others. There are better and safer alternatives available.

Ashwagandha Extract

Ashwagandha has been used for thousands of years, mainly to treat conditions based around anxiety and stress.

While it hasn't been studied in regards to sleep quality too much, there is ample evidence that it can lower anxiety and stress levels.

The few studies that do exist suggest that ashwagandha can make falling asleep easier (40):

The ashwagandha root extract can be mixed into water or milk is appears to rarely cause any side effects.

See our full review on if ashwagandha can help insomnia for more details.

Magnesium Supplements

Most magnesium supplements are bought to try and improve sleep. Magnesium glycinate is the most popular, and touted as the most absorbable form.

Magnesium is involved in a ton of things in your body, including muscle contraction and relaxation (12). A deficiency can cause many side effects, ranging from restless leg syndrome to depression (13).

Magnesium is also needed for the function of certain neurotransmitters (e.g. GABA), so it can affect sleep in multiple ways.

A study of magnesium supplementation in elderly patients with insomnia showed promising results (14):

Supplementation of magnesium appears to improve subjective measures of insomnia such as ISI score, sleep efficiency, sleep time and sleep onset latency, early morning awakening, and likewise, insomnia objective measures such as concentration of serum renin, melatonin, and serum cortisol, in elderly people.

Elderly people are often deficient in magnesium, so it makes sense that a supplement could help.

A combination of melatonin, magnesium, and zinc was effective at improving sleep quality and quality of life of residents in a long-term care facility (15).

Another study treated patients with a magnesium, melatonin, and vitamin B complex, which also yielded positive results for insomniacs (16).

Note that some forms of magnesium supplements affect insomnia differently.

SummaryResearch suggests that magnesium supplements can help improve sleep quality. And because magnesium is a mineral that’s already in our food, we know it’s pretty darn safe, and can be used alongside other supplements like melatonin or vitamin B.

GABA Supplements

Sleep and wake states are governed by complex interactions between neurotransmitters in the brain.

GABA is one of the most important neurotransmitters, which is why many sleep medications like benzodiazepines work by enhancing transmission at GABA receptors.

If you go on Amazon, there are a decent number of “GABA” supplements.

But it’s tricky, because GABA in certain parts of the brain increases sleep, while GABA in other parts can increase wakefulness (17). So it’s not necessarily a good idea just to flood your brain with exogenous GABA.

It could be, but let’s take a look at the research.

There’s not too much on GABA supplements, but a 2015 review found that (18):

There is some evidence in favor of a calming effect of GABA food supplements, but most of this evidence was reported by researchers with a potential conflict of interest. We conclude that the mechanism of action of GABA food supplements is far from clear, and that further work is needed to establish the behavioral effects of GABA.

There’s some evidence for it, and some against it.

Many people claim that they get a benefit from it, but the mechanism behind how it would help is unclear. It may just be a placebo effect.

SummaryIt’s possible that GABA supplements could improve sleep, but there’s not enough evidence currently either way to make a conclusion.

L-Theanine

L-Theanine is a non-protein amino acid that’s found in certain types of tea. It’s why certain types of green tea can be good for sleep despite having some caffeine in them.

Studies do show that green tea improves sleep quality when low caffeine versions are consumed (19).

But now there are L-Theanine supplements for insomnia where it has been extracted (so now caffeine present). Common sense would say that these should be a safe way to improve sleep, but again, let’s look at the research.

A 6 week study in boys with ADHD found that 400 mg of L-theanine per day was safe and improved some aspects of sleep quality (20).

They didn’t get to sleep any faster, but woke up fewer times during the night.

A larger literature review found a similar overall result, that L-theanine supplements did not reduce sleep latency or increase total sleep time, but improves sleep efficiency (21):

Zolpidem and L-theanine both displayed a poor response in reducing sleep latency and increasing total sleep time, however L-theanine did produce an increase in sleep efficiency.

Finally, a GABA and L-theanine mixture was given to rats in a 2019 study, and found that this combination was more effective than either supplement given alone (22). So it’s possible that L-theanine could be a part of a mixture of sleep aids to improve results.

SummaryOverall, there are limited studies on L-Theanine supplements, but it does seem to have some beneficial effect on sleep efficiency, particularly in those that have restless sleep and are prone to waking up often. Additionally, I could find no big safety concerns at the present as long as suggested dosages are followed.

Valerian Root

It seems as though using valerian root for insomnia was quite popular in the past, as there are quite a few old studies done on it.

However, most of the research is low quality, and the studies that have a solid methodology show (23):

The available evidence suggests that valerian might improve sleep quality without producing side effects

If you dig into the studies, some show no significant change in sleep quality (24), while others show some improvement in sleep onset latency.

The effect size is relatively small in any case.

Additionally, there are some safety concerns with large doses of valerian. A literature review found (25):

...a greater number of (adverse) events per person were reported with valerian...

When it comes to "natural" sleeping aids (take valerian root vs melatonin for example), I wouldn't consider valerian root to be the most promising.

SummaryValerian root may have a positive effect on sleep onset latency (time to fall asleep), however, more research is needed to confidently make that claim. But even in the best case scenario, it doesn’t seem to have that much of a positive impact, and there are some safety concerns.

Chamomile (or Chamomile Extract)

Chamomile tea is known for being calming, so it’s not unreasonable to think it might improve sleep quality.

A 2015 metastudy of herbs found no significant difference between chamomile and a placebo in currently available studies, but does note that more research is needed (25).

Let’s take a look at a few individual studies.

First, postpartum women drank chamomile tea for a period of 2 weeks to try and improve depression and sleep quality. There was a modest short term benefit that was gone by the 4-week followup (26).

In a double-blind, placebo-controlled pilot of 34 insomnia patients, the test group consumed 270 mg of chamomile twice per day for 28 days (27). They found:

There were no significant differences between groups in changes in sleep diary measures, including total sleep time (TST), sleep efficiency, sleep latency, wake after sleep onset (WASO), sleep quality, and number of awakenings.

Finally, one study that did show a positive outcome had elderly patients take chamomile extract capsules (200 mg) twice a day for 28 consecutive days (28). Sleep quality, measured by the Pittsburgh Sleep Quality Index, improved significantly:

See our full guide on if chamomile helps insomnia for a more detailed look.

SummaryChamomile may have a limited benefit for sleep quality in certain people, but overall it has a small or non-existent impact.

Passionflower Herb

Passionflower herb (Passiflora incarnata) is another popular herb that many claim helps sleep quality.

Unfortunately, there aren’t too many studies involving it, and most show that passionflower has a small impact on insomnia at best.

Animal studies do show some sedative effects (29).

A 2013 study compared zolpidem (a sleep medication) to a mixture of valerian and passionflower and found (30):

There was significant improvement in total sleep time, sleep latency, number of nightly awakenings and insomnia severity index scores in both groups. However, no statistically significant difference was observed between the groups.

While it’s just one study, that’s a positive result.

And finally, a double-blind, placebo controlled study found that (31):

These initial findings suggest that the consumption of a low dose of Passiflora incarnata, in the form of tea, yields short-term subjective sleep benefits for healthy adults with mild fluctuations in sleep quality.

Note that sleep quality was measured by sleep diaries, which aren’t the most robust way of tracking changes.

SummaryWay more research is needed on the efficacy of passionflower herb, but the limited evidence out there suggests that it can have a positive effect on sleep quality.

Lemon Balm Leaf

A final popular herb in natural sleep aid products is lemon balm.

Again, there’s not too much research on lemon balm and insomnia.

One study found that a mixture of valerian and lemon balm were (subjectively) effective treating restlessness in children (32). I say subjectively because the results were tracked based on a combination of ratings from investigators and parents.

A placebo controlled trial of insomniacs had a treatment group receiving 1000 mg of lemon balm (Melissa officinalis) and 400 mg N. menthoides (33). They found that insomnia severity significantly improved in the 4 week trial (PSQI scores went from 16.69 to 11.30).

Finally, burn patients drinking lemon balm tea found that sleep quality improved significantly (34).

Those studies are really all there is on lemon balm and sleep. They all have quite substantial limitations, so we can’t conclude anything.

SummaryThere’s a limited amount of research on lemon balm and sleep. It does seem like it could have a significant benefit for some people with sleep trouble, but there’s not enough evidence to conclude anything.

Ginseng

Ginseng is used for many different purposes, but does show that it might have some use for improving sleep quality as well.

There haven’t been many human studies that have focused on ginseng’s effect on sleep in humans, but a few have shown promise.

In one, 16 subjects were given ginseng for 2 days and found that it increased total sleep time and sleep efficiency (Fermented Ginseng Improves the First-Night Effect in Humans).

One risk with ginseng is that there are some relatively common side effects that could actually make sleep worse, especially if too much is consumed.

You can see our full review on if ginseng can cause insomnia if you’d like to learn more.

Weighted Blankets

Using weighted blankets for sleep trouble are gaining a lot more attention from the general public lately.

A 2020 systematic review found 8 studies of weighted blankets with solid methodologies (35). Their conclusion was:

Weighted blankets may be an appropriate therapeutic tool in reducing anxiety; however, there is not enough evidence to suggest they are helpful with insomnia.

But we know that anxiety can be a big part of insomnia for many people, so there certainly could be a benefit of weighted blankets for certain people with sleep issues.

Let’s look at a few individual studies.

First, researchers looked at the impact of weighted blankets on children with autism (36). They found that while both the children and parents liked the blankets, it didn’t actually improve sleep quality at all.

Another study found that insomnia patients using weighted chain blankets over a 12 month period did see a positive effect on insomnia severity (37). The mean level on the ISI (insomnia severity index) went from “severe” to “subthreshold insomnia.” So it was by no means a complete cure, but made a significant impact.

Finally, another study found that sleep time increased, and movement during sleep decreased when using weighted blankets (38). Again, patients subjectively liked the blankets, and reported they felt more refreshed in the morning.

SummaryResearch doesn’t fully support the use of weighted blankets as part of treatment for insomnia at this point. However, it does show that most people like how they feel, and they can have some impact on sleep quality for people with sleep difficulties.

Sleep Masks

There aren’t too many studies on sleep masks, partly because they’re not that complicated.

They block out light, which should be useful for sleeping better in bright conditions, as long as they’re not too uncomfortable.

Most studies on eye masks are geared towards medical settings like ICUs.

Not surprisingly, they find that eye masks (and earplugs) improve sleep quality in people that are exposed to simulated ICU noise and light (39).

SummaryIf your bedroom has a lot of light for some reason, an eye mask can be effective at improving sleep quality. Similarly, ear plugs are useful in loud environments.

Summary: Which Sleeping Aids Are Backed By Science?

3,000 or so words later, let’s sum up what we’ve seen.

Sleeping aids that have a relatively strong amount of evidence behind them:

Melatonin - Have a significant impact on sleep quality (particularly sleep onset time) in most people with sleep issues. However, safety research on long term research is needed, and many melatonin supplements have a different amount of melatonin in them than what the label claims.
Magnesium - In those with low magnesium levels, magnesium supplements are a safe way to improve sleep quality. It can also be used alongside other supplements like melatonin.
L-Theanine - The limited research on L-theanine mostly shows a small, positive effect on sleep efficiency (by decreasing frequency of waking up). No serious safety concerns.
Weighted blankets - Research shows that most people find weighted blankets comfortable and that they can have a positive impact on sleep quality. However, there’s not enough evidence for physicians to recommend them as part of insomnia treatment.
Sleep masks (situational) - For people exposed to significant amounts of light during sleep, sleeping masks are effective at improving sleep quality.

Next, let’s look at sleeping aids that have some promising evidence, but not enough to conclude that they are highly effective for most people. This is where all the herbs fall into:

Ashwagandha - This is pretty close to fitting into the above category. The existing research looks promising, but more studies in the coming years will help identify how reliably ashwagandha can affect sleep positively.
Passion flower - Arguably the most promising herbal sleep aid. Evidence does mostly point to a small, but significant impact on sleep quality, with no big safety risks for most people.
Lemon balm - There is some evidence (but lacking overall) that lemon balm could have a positive impact on sleep quality.
GABA supplements - There is some evidence that GABA supplements could improve sleep, but it is far from proven at this point.
Chamomile - Research suggests that it has a small, if any, benefit on sleep quality.

Finally, a few of the aids fall more into a “controversial” category:

5-HTP - Studies are mixed on the effect of 5-HTP. In some people it does appear to have a small, but positive effect. In others, it may make sleep worse. There are safer and more effective alternatives to increase serotonin levels.
Valerian root - There’s definitely some research that suggests that valerian root has a positive impact on sleep onset latency. However, the effect size is relatively small in most cases, and there are currently some safety concerns (e.g. potential adverse effects like diarrhoea).

I’ll wrap this up by clearly saying that I’m not a doctor, and you shouldn’t blindly use any of these without consulting a doctor. There may be certain risks associated with some of these that are specific to you, so getting a professional opinion is a pretty good idea.

I’ll try to keep this page updated over time as new studies come out.

References

Medical Disclaimer: The information on SnoozeUniversity.com is not intended to be a substitute for physician or other qualified care. We simply aim to inform people struggling with sleep issues about the nature of their condition and/or prescribed treatment.

About the authorDale is the founder of Snooze University and a sleep researcher. I overcame my sleep issues and now I'd like to help you do the same by summarizing the latest sleep studies for you.