Snooze University

Melatonin for Insomnia: Here's When to Try It

by Dale Cudmore | Updated: May 28, 2023

Melatonin might just be the best over the counter natural sleep aid.

While it doesn’t work for everyone, there’s a lot of research spanning decades that shows it can improve sleep quality aspects like time to get to sleep and total sleep time.

I’m going to walk you through that research while answering common questions about using melatonin as part of treatment for insomnia.

Does Melatonin Improve Sleep Quality?

The majority of peer-reviewed studies have found that melatonin has a positive effect on sleep quality on most people with sleep trouble.

The chart below visually shows the effects of melatonin on sleep onset latency (time to fall asleep) from a meta-analysis of melatonin studies (1):

The overall mean of those studies is improving sleep onset latency by just under 10 minutes compared to a placebo. The more important observation is that almost every study found a positive effect, showing some reliability in the findings.

While it varies by individual, the most common benefits of melatonin are (2,3):

  • Decreased sleep onset latency
  • Increased overall sleep time
  • Improved sleep quality

The meta-analysis mentioned above makes one final note that is important:

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

In other words, melatonin is not going to fix insomnia by itself.

SummaryThere’s evidence that melatonin is effective at improving sleep quality in people with sleep problems. However, melatonin should only be 1 part of a treatment plan for those with insomnia.

How Does Melatonin Make It Easier to Fall Asleep?

Melatonin works by giving us a bit of control over the circadian rhythm, which is the internal cycle that governs our energy levels and sleep.

The circadian rhythm is mostly governed by daylight and temperature. As the sun and temperature goes down, the body starts producing the hormone melatonin, which makes you feel sleepy.

Unfortunately, blue light from screens can cause insomnia, or just sleep problems in general, because blue light limits the production of melatonin.

If your melatonin levels are low when you go to bed, it takes about 30-60 minutes for them to rise to sufficient levels to get to sleep. In that time, sleep anxiety can creep in and make it take even longer to get to sleep.

Additionally, delaying the onset of melatonin production delays the entire circadian rhythm, which can have effects on other aspects of sleep quality.

SummaryMelatonin supplements can be taken about 30 minutes before bed to quickly raise melatonin levels and compensate for any blue light exposure in the environment. This can help certain people fall asleep faster.

When Does Melatonin Work The Best?

Melatonin works best for people who have sleep issues due to circadian rhythm delays, which are common in people with (4):

However, as we saw before, it often has a beneficial effect on most people to some degree, with blue light being a likely explanation.

Studies have also shown that melatonin can be safe and effective in children, even those with autism (5).

Not All Melatonin Supplements Are Effective

While it varies by country, over the counter supplements like melatonin aren’t generally well regulated. That's why it's important to stick to the best melatonin supplements.

One study examined 31 brands of melatonin-containing sleep supplements and found a somewhat shocking statistic on melatonin that the melatonin content varied significantly from the label in many of the products (6):

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.

I wish they would have named the brands they looked at, but unfortunately the authors did not.

Here’s a quick look at the variation in the products in one lot of melatonin supplements that were examined:

There’s a few takeaways from these plots:

  • Chewable melatonin tablets and strips had the most variation in melatonin content
  • Liquid melatonin, time released melatonin, sublingual tablets, and “normal” (swallowed) tablets had relatively low variation from the label.
  • One brand had 478% of the melatonin content claimed on the label, while one had -83%.

SummaryMany melatonin supplements don’t have the correct amount of melatonin in them as claimed on the label, and even contain other products. Stick to reputable brands of melatonin in one of the 4 forms mentioned just above.

How Much Melatonin Is Best for Sleep?

Research shows that optimal melatonin dosage for adults is somewhere between 0.5 and 5 mg (7).

However, studies use anywhere from 0.1 to 10 mg, and see effects with even small doses.

Those new to using melatonin should start on the low end and up the dosage only if needed. There's evidence that shows that taking too much melatonin can worsen sleep.

Can You Overdose on Melatonin?

In general, melatonin is a very safe supplement, but there’s a lack of evidence showing how safe large doses of melatonin are.

One study had patients take 1,000 mg (that’s about 200 times the recommended dose) for 4 weeks and saw no significant health issues (8):

While changes in pituitary hormones were observed, no toxic effects were reported.

However, there have been a few case studies where children have suffered negative health effects like severe hypotension after consuming too much melatonin (9).

SummaryMelatonin is effective in small doses. While larger doses are generally safe for adults, they do not improve the effectiveness.

Is Long Term Use of Melatonin Effective and Safe?

Studies on long term melatonin supplementation shows that it is safe and the effects are not reduced over time.

This is an advantage over other sleep medication that patients can develop tolerances to.

One study found that melatonin use for 7 years did not result in substantial deviations of sleep quality (10).

Similarly, studies in children have shown that melatonin is well-tolerated even in those with autism, and was effective and safe even after 52 weeks (11,12).

Summary: Melatonin for Insomnia

Melatonin is a natural sleep aid that can improve sleep quality in many people with sleep problems. It has more evidence behind it than most other popular sleep aids (see melatonin vs valerian root).

Most notably, it usually makes it easier to fall asleep.

Research shows that its effects last during long term usage, and there are no significant safety concerns for most people if the supplement dosage instructions are followed.

However, melatonin is not a cure for insomnia in the majority of cases. It can be part of a treatment plan that is prepared by a doctor, but it’s unlikely to be effective enough on its own. Furthermore, it doesn’t address the root cause of sleep issues, which should be the goal of treatment.


  1. Meta-Analysis: Melatonin for the Treatment of Primary Sleep Disorders
  2. A review of sleep disorders and melatonin
  3. Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders
  4. New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation
  5. Efficacy and Safety of Pediatric Prolonged-Release Melatonin for Insomnia in Children With Autism Spectrum Disorder
  6. Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin Content
  7. Melatonin for the prevention and treatment of jet lag
  8. The effects of oral melatonin on skin color and on the release of pituitary hormones
  9. An Upsurge in Melatonin Overdose,Severe Hypotension in an Adolescent After a Melatonin Overdose
  10. Long-Term Melatonin Therapy for Adolescents and Young Adults with Chronic Sleep Onset Insomnia and Late Melatonin Onset
  11. Long-Term Efficacy and Safety of Pediatric Prolonged-Release Melatonin for Insomnia in Children with Autism Spectrum Disorder
  12. Efficacy and safety of melatonin for sleep onset insomnia in children and adolescents: a meta-analysis of randomized controlled trials

Medical Disclaimer: The information on 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.