Sustained Release Melatonin for Better Sleep. Does It Work?
TLDR
A 2026 randomized, double blind, placebo controlled trial found that 2 mg of sustained release melatonin taken nightly for 28 days improved several objective and subjective measures of sleep in otherwise healthy adults with poor sleep quality. Participants taking sustained release melatonin slept longer, fell asleep faster, spent less time awake during the night, and reported better sleep quality and daytime well being than those taking placebo.
One of the most interesting findings was that the benefit was not limited to falling asleep. Sustained release melatonin also appeared to help participants stay asleep, which is one potential advantage of a formulation designed to release melatonin gradually throughout the night. However, the study was small, lasted only 28 days, and was funded by the company that manufactured the melatonin product, so the findings should be confirmed independently.
Can Sustained Release Melatonin Help You Sleep Better?
Melatonin is one of the most popular sleep supplements available.
But there is an important problem with the way many people think about it.
Most melatonin supplements are designed primarily to help you fall asleep.
What if your bigger problem is waking up repeatedly during the night?
Or falling asleep normally but waking at 2:00 or 3:00 in the morning and struggling to get back to sleep?
That is where sustained release melatonin becomes particularly interesting.
A new randomized clinical trial published in Clocks & Sleep examined whether a low dose, sustained release melatonin supplement could improve not only sleep onset, but also sleep maintenance, total sleep time, sleep efficiency, daytime fatigue, and overall well being.
The results were encouraging.
What Is Sustained Release Melatonin?
Melatonin is a hormone naturally produced by the pineal gland in the brain.
Its production follows a daily rhythm.
Melatonin levels typically begin rising in the evening as darkness approaches, helping signal to the body that it is time to sleep. Levels remain elevated during the night and gradually fall toward morning.
Supplemental melatonin attempts to reinforce that natural signal.
However, conventional immediate release melatonin is absorbed relatively quickly.
That can be useful when the primary problem is falling asleep, but the short duration of elevated melatonin may be less helpful when the problem is staying asleep throughout the night.
Sustained release formulations are designed differently.
They typically release part of the melatonin relatively quickly and then continue releasing the remainder over several hours. The goal is to maintain more stable melatonin concentrations throughout the night and better mimic the body's natural overnight secretion pattern.
In theory, that could provide two benefits:
Help you fall asleep.
Help you stay asleep.
This new study tested whether that theory translates into measurable improvements in actual sleep.
The Study
Researchers conducted a multicenter, randomized, double blind, placebo controlled trial in adults between 30 and 60 years old who reported poor sleep quality.
A total of 62 participants were enrolled.
They were randomly assigned to receive either:
2 mg of sustained release melatonin
or
A matching placebo
every night for 28 days.
Fifty nine participants completed the study and were included in the final per protocol analysis:
28 in the melatonin group
and
31 in the placebo group.
Participants were instructed to take the supplement approximately 30 to 60 minutes before bed, preferably between 9:00 and 9:30 PM.
That timing is useful because it gives us a practical idea of how the intervention was actually used.
The Researchers Used Objective Sleep Testing
One of the biggest strengths of this study was the use of polysomnography, commonly called PSG.
PSG is considered one of the most comprehensive methods for objectively measuring sleep.
Instead of simply asking someone whether they felt like they slept better, researchers measured physiological sleep parameters, including:
- Sleep efficiency
- Sleep onset latency
- Wake after sleep onset
- Total sleep time
- NREM sleep
- REM sleep
The researchers also used validated subjective assessments, including the Pittsburgh Sleep Quality Index, sleep diaries, and the WHO 5 Well Being Index.
That allowed them to examine whether participants actually slept differently as well as whether they felt like they slept better.
Sleep Efficiency Improved
One of the clearest findings involved sleep efficiency.
Sleep efficiency refers to the percentage of time you spend asleep while you are actually in bed.
For example, if you are in bed for eight hours but spend an hour awake, your sleep efficiency is lower than someone who sleeps almost the entire time.
After 28 days, sleep efficiency increased in the sustained release melatonin group while it declined in the placebo group.
The mean change was:
Sustained release melatonin: +3.49 percentage points
Placebo: minus 6.30 percentage points
The difference between groups was statistically significant.
Researchers calculated a Cohen's d of 0.9, indicating a large treatment effect for sleep efficiency in this trial.
That is one of the more impressive findings in the study.
Participants Fell Asleep About 10 Minutes Faster
The sustained release formulation also improved sleep onset.
At baseline, participants in the melatonin group took an average of about 42 minutes to fall asleep.
After 28 days, that declined to approximately 31 minutes.
The average change was:
Minus 10.28 minutes with sustained release melatonin
compared with
Plus 16.70 minutes with placebo.
This suggests sustained release melatonin was still capable of helping with sleep initiation despite being designed to extend melatonin exposure through the night.
That is important because an ideal sustained release formulation should not force you to choose between falling asleep faster and staying asleep longer.
Participants Spent Less Time Awake During the Night
This may be the most important result for people who struggle with fragmented sleep.
Researchers measured wake after sleep onset, often abbreviated WASO.
This reflects how much time someone spends awake after initially falling asleep.
After 28 days, the sustained release group reduced WASO by approximately:
14.92 minutes
while the placebo group increased by:
24.71 minutes.
That suggests sustained release melatonin may be particularly useful for sleep maintenance, not just sleep initiation.
In practical terms, participants spent less time lying awake during the night.
Total Sleep Time Increased
The melatonin group also slept longer.
Total sleep time increased by approximately:
23.83 minutes
from baseline in the sustained release group.
Meanwhile, total sleep time decreased by about:
39.25 minutes
in the placebo group.
By day 28, participants taking sustained release melatonin were averaging approximately 6.5 hours of objectively measured sleep.
That is still below the amount of sleep most adults should ideally obtain, but moving sleep duration in the right direction is meaningful for people struggling with poor sleep.
NREM Sleep Improved Too
Researchers also examined sleep architecture.
Sleep is not one uniform state.
Throughout the night, your brain cycles between non rapid eye movement sleep and rapid eye movement sleep.
NREM sleep includes stages associated with physical restoration and increasingly deep sleep.
After 28 days, NREM sleep duration increased by approximately:
21.21 minutes in the sustained release group
while decreasing by approximately:
21.44 minutes in the placebo group.
REM sleep also moved favorably compared with placebo.
The melatonin group increased REM sleep by approximately 2.27 minutes, while the placebo group declined by approximately 15.69 minutes.
It is worth noting that the within group REM increase in the melatonin participants was not statistically significant by itself. The significant result came from the difference in change between the two groups.
So it would be too strong to claim that sustained release melatonin dramatically increases REM sleep.
The better interpretation is that the melatonin group maintained sleep architecture better than placebo during the study.
People Started Feeling Better Within One Week
The objective findings were supported by participants' own reports.
Sleep quality was measured using the Pittsburgh Sleep Quality Index, or PSQI.
Lower scores indicate better sleep quality.
Compared with placebo, PSQI improved significantly in the sustained release group starting after only seven days.
Changes from baseline were:
Day 7: minus 2.21 points
Day 14: minus 4.86 points
Day 28: minus 5.61 points
The placebo group improved by only about 0.65 points by day 28.
Interestingly, the researchers point out that the magnitude of improvement was larger than the average effect reported in a previous meta analysis of 23 randomized melatonin trials.
That is intriguing, although this single small study should not be assumed to overturn the broader research literature.
Better Sleep Was Associated With Better Daytime Well Being
Sleep problems do not end when the alarm clock goes off.
Poor sleep can affect energy, mood, concentration, motivation, and overall quality of life throughout the following day.
Researchers therefore measured psychological well being using the WHO 5 Well Being Index.
By day 14, the melatonin group improved significantly more than placebo.
The mean improvement was:
Day 14: +9.86 versus +0.77
and
Day 28: +13.29 versus +0.77.
Participants also reported improvements in several practical daytime outcomes.
Compared with placebo, the melatonin group reported:
- Less daytime fatigue
- Less daytime napping
- Less daytime stress
- Greater daytime alertness
- Fewer nighttime awakenings
- Greater restfulness
This is an important point.
A sleep supplement is not particularly useful if it makes you sleep at night but leaves you groggy the following day.
In this trial, participants actually reported better daytime alertness, not worse.
Why Sustained Release May Work Differently From Regular Melatonin
The difference comes down to timing.
Immediate release melatonin produces a relatively quick increase in blood melatonin levels.
That may provide a strong signal that it is time to fall asleep.
But because melatonin has a relatively short duration in circulation, blood levels may decline relatively quickly.
Sustained release formulations attempt to create a different pattern.
The formulation tested in this study was designed to release melatonin gradually and maintain melatonin concentrations across an approximately eight hour sleep period.
That may explain why the strongest results involved both:
Falling asleep
and
Staying asleep.
The study's polysomnography results showed improvements in sleep onset latency, wake after sleep onset, total sleep time, and sleep efficiency, supporting the idea that prolonged exposure may influence several different parts of the night.
Does This Mean Sustained Release Melatonin Is Better Than Immediate Release?
Not necessarily.
This study did not directly compare sustained release melatonin with immediate release melatonin.
It compared sustained release melatonin with placebo.
That means we cannot conclude from this trial that sustained release is universally superior.
The most reasonable way to think about the two formulations is based on the problem you are trying to solve.
Immediate release melatonin may make more sense when the main problem is falling asleep or shifting circadian timing.
Sustained release melatonin may theoretically make more sense when the problem involves waking repeatedly or difficulty maintaining sleep.
But a direct head to head trial would be needed to establish which formulation performs better for different sleep problems.
More Melatonin Is Not Necessarily Better
Another interesting feature of this study is the dose.
Participants took just:
2 mg per night.
Many commercial melatonin supplements contain 5 mg, 10 mg, or even more.
This study demonstrates that relatively low doses can still produce measurable effects when paired with an appropriate delivery system.
The authors also discuss previous research showing mixed results across different sustained release doses and formulations. Some trials found benefits with 2 to 5 mg, while others found little benefit with different formulations or populations.
That suggests the question may not simply be:
How many milligrams are you taking?
The release profile, population, timing, and formulation may matter too.
Was Sustained Release Melatonin Safe?
Over the 28 day study, sustained release melatonin appeared to be well tolerated.
There were no serious adverse events.
Five participants in the melatonin group reported nine adverse events, primarily:
- Headache
- Dizziness
Six participants in the placebo group reported eight similar events.
Researchers classified all adverse events as mild and considered them unlikely to be related to the study supplement. All resolved without lasting problems.
No clinically significant changes were found in blood pressure, heart rate, body temperature, oxygen saturation, respiratory rate, physical examinations, or laboratory testing during the study.
That said, 28 days is a short safety window.
The study cannot tell us much about the safety or effectiveness of taking this formulation continuously for months or years.
An Important Caveat: The Placebo Group Got Worse
There is one unusual feature of the results that deserves attention.
Several objective sleep measurements deteriorated in the placebo group over the 28 days.
For example, sleep efficiency and total sleep time both fell substantially in the placebo participants.
That made the difference between groups larger.
The authors acknowledge that they do not know exactly why this happened. They suggest normal variability in sleep, progression of existing sleep problems, or the absence of an active intervention could have contributed.
This means some of the impressive between group differences were driven by both improvement in the melatonin group and worsening in the placebo group.
That does not invalidate the results.
But it is an important reason to avoid interpreting the headline numbers too aggressively.
Another Important Caveat: The Study Was Industry Funded
Transparency matters when evaluating supplement research.
This trial tested Melotime, a sustained release melatonin formulation manufactured by Nutriventia Private Limited.
The study was also funded by Nutriventia.
Three of the study authors were Nutriventia employees, one of whom also had an ownership interest. Another author received consulting fees from the company.
That does not mean the findings are wrong.
The study used several methodological strengths, including randomization, double blinding, a matching placebo, and objective polysomnography.
The sponsor, investigators, participants, and site personnel involved with assessments were blinded to treatment assignment until the database was locked.
Still, independent replication would substantially strengthen confidence in the findings.
Important Limitations
This study has several limitations worth keeping in mind.
First, it was relatively small.
Only 59 people completed the study, so larger trials are needed.
Second, the intervention lasted only 28 days.
We do not know whether the benefits would persist with long term use or whether tolerance, side effects, or other issues could emerge.
Third, participants were otherwise healthy adults with poor sleep quality.
These results should not automatically be applied to people with diagnosed insomnia, sleep apnea, neurological disease, shift work disorder, or other specific sleep conditions.
Fourth, the placebo group experienced unexpected deterioration in several objective sleep measures.
Finally, the product was manufactured and the research funded by the same company, making independent replication especially important.
What Does This Mean for Someone Considering Melatonin?
The biggest takeaway from this study is not necessarily that everyone should start taking melatonin.
Instead, it highlights the importance of matching the formulation to the sleep problem.
If you primarily struggle to fall asleep, immediate release melatonin may be sufficient.
If you frequently wake throughout the night, sustained release melatonin may be worth discussing with a healthcare professional because it is designed to maintain melatonin exposure for longer.
And if your sleep problems are persistent, worsening, or accompanied by loud snoring, gasping, excessive daytime sleepiness, or other symptoms, a supplement should not replace evaluation for an underlying sleep disorder.
Simply Good Tip
With melatonin, more is not automatically better.
This study produced meaningful improvements using just 2 mg taken approximately 30 to 60 minutes before bed.
That reinforces an important supplement principle.
Instead of automatically reaching for a 5 or 10 mg product, pay attention to the dose, delivery system, and reason you are using melatonin in the first place.
If staying asleep is the problem, the release profile may matter as much as the number of milligrams on the label.
The Bottom Line
This randomized, double blind, placebo controlled trial provides encouraging evidence that 2 mg of sustained release melatonin may improve both falling asleep and staying asleep in adults with poor sleep quality.
After 28 days, sustained release melatonin was associated with:
- Higher sleep efficiency
- Approximately 24 additional minutes of sleep from baseline
- Faster sleep onset
- Less time awake during the night
- More NREM sleep
- Better subjective sleep quality
- Less daytime fatigue
- Better daytime alertness
- Improved psychological well being
That combination is particularly interesting because conventional melatonin is often thought of primarily as a tool for falling asleep.
This study suggests a sustained release formulation may also help with sleep maintenance.
However, the trial was small, lasted only four weeks, and was industry funded. Larger independent trials are needed before we can confidently say sustained release melatonin is superior to standard melatonin or determine who benefits most.
For now, the research supports a simple idea:
When it comes to melatonin, how the supplement releases throughout the night may matter just as much as how much you take.
References
- Thanawala S, Shah R, Lopes A, Kulkarni M, Jain B, Andhalkar N. Efficacy and Safety of Sustained Release Melatonin Capsules (2 mg) in Healthy Adults with Poor Sleep Quality: A Randomized, Double Blind, Placebo Controlled Trial. Clocks & Sleep. 2026;8:31.
- The authors' review of previous prolonged release melatonin research reported that 2 mg prolonged release melatonin reduced sleep onset latency in older adults with primary insomnia, while other studies produced mixed results depending on dose, formulation, and study population.
- A meta analysis cited in the paper that included 23 randomized trials found that melatonin produced an average improvement of approximately 1.2 points on the Pittsburgh Sleep Quality Index across heterogeneous populations.
Frequently Asked Questions
How much sustained release melatonin was used?
Participants took 2 mg once each night for 28 days, approximately 30 to 60 minutes before sleep.
Did sustained release melatonin help people fall asleep faster?
Yes. Sleep onset latency improved by approximately 10.3 minutes from baseline in the sustained release group, while it worsened in the placebo group.
Did it help people stay asleep?
Yes. Wake after sleep onset decreased by approximately 14.9 minutes in the sustained release group, while increasing by approximately 24.7 minutes in the placebo group.
Did sustained release melatonin increase total sleep time?
Yes. Total sleep time increased by approximately 23.8 minutes from baseline after 28 days in the melatonin group.
Is sustained release melatonin better than regular melatonin?
This study cannot answer that question because it compared sustained release melatonin with placebo, not immediate release melatonin. A direct comparison trial would be needed.
Is 2 mg of melatonin enough?
In this trial, 2 mg produced significant improvements in several sleep measures. That does not establish 2 mg as the ideal dose for everyone, but it does show that higher doses are not necessarily required to produce an effect.
