How Long Does Melatonin Last? It Depends On Where You Get It

Need melatonin supplements? Your body already produces enough melatonin for you to fall asleep and stay asleep. You can harness it with good sleep hygiene.

How long does melatonin take to work, and how long does melatonin last? If you’re having trouble sleeping and you’re asking these questions about melatonin supplements, there are two other questions to ask yourself first: 

  • Why am I not sleeping through the night? 
  • Do I really need to take a melatonin supplement? 

Although melatonin is among the most popular supplements in the United States, you don't need to take it to fall asleep quickly and sleep through the night. That’s because there is another form of melatonin that’s completely free and far superior to anything you can buy. And it’s made inside your own brain! 

The melatonin your body produces plays an essential role in your ability to fall asleep and stay asleep at night. And finding ways to optimize this biological process will help you get the sleep you need so you have ample energy during the day. Designing a daily schedule that follows your circadian rhythm, or internal clock, is the best way to support your body’s melatonin production for the best sleep you can get. 

Rest assured, this article will answer your questions about melatonin supplements. But our main goal is to share tips on how you can get the sleep you need without spending a dime. We’ll explain how good sleep hygiene — especially being strategic about the timing of your light exposure — can help you make the most of your body’s natural melatonin production for optimal sleep and daytime energy.

What Is Melatonin? 

​​Melatonin is a naturally occurring hormone that promotes sleepiness. The melatonin your brain produces helps regulate your circadian rhythm — the internal clock that tells your body when to sleep and when to be awake over a roughly 24-hour cycle. 

Even though melatonin is naturally produced by your body, over-the-counter melatonin supplements (exogenous melatonin) are also available. They are packaged and marketed as sleep aids and can be made synthetically or from animal glands.

Understanding Your Body’s Melatonin Production

how long does melatonin last: infographic of the circadian rhythm

Before seeking out melatonin that was made in a lab or bottled in a factory, why not look for ways to boost the unbranded, bespoke version produced by your very own brain? It’s easier than you might think. And asking the right questions can help shed some light on how your natural melatonin works. Let’s start with the basics.

How and When Does Your Brain Produce Melatonin?

Melatonin is produced at night in the brain’s pineal gland in response to signals from the suprachiasmatic nucleus (SCN), a special group of neurons in the hypothalamus. As the master clock of your circadian rhythm, the SCN is attuned — via the retina and optic nerve — to the cycle of changing light we experience every 24 hours. In the dark of night, the SCN prompts the pineal gland to secrete melatonin. The TL;DR here is — to produce melatonin, you have to be in the dark.

How Does Melatonin Make You Feel Sleepy at Night?

After dark, melatonin preps your body for sleep by lowering your body temperature, blood pressure, stress hormones, and alertness. This time of night, which usually falls 2-3 hours before you go to sleep, is known as dim light melatonin onset (DLMO). It marks the start of what the RISE app calls your Melatonin Window, the period when your brain produces its highest levels of melatonin that it will all night. Going to bed during this window will give you the best chance of falling asleep quickly and staying asleep through the night. The RISE app can tell you your ideal bedtime each day based on your Melatonin Window.

How Does Light Affect Melatonin Production and Sleep? 

Just as darkness prompts the production of melatonin, exposure to light suppresses it. That works out perfectly in the morning, as exposure to sunlight can help you feel more awake as you start your day. But light exposure at night can be problematic, especially in the 90 minutes before bedtime. Using artificial lighting at night can trick your brain into thinking it’s still daytime. Even small amounts of light exposure will inhibit or delay natural melatonin release and make it much more difficult to fall asleep and stay asleep during the night. 

Harness the Power of Your Body’s Natural Melatonin

how long does melatonin last: person sleeping with an eye mask on

Good sleep hygiene — the upkeep of behaviors that influence the way you sleep — starts first thing in the morning and is essential for optimal melatonin production. Light is the strongest of all circadian cues, and being strategic about the timing of your light exposure can help you harness the power of your body’s natural melatonin production and set you up for better sleep and energy outcomes.

Follow these light guidelines to optimize your sleep and energy levels:

  • Let the sunshine in: Open the curtains or go outside for a walk. When you expose yourself to sunlight soon after you get up in the morning, your brain stops producing melatonin, signaling the end of the sleep phase and the beginning of your waking hours. It will also set you up for restful sleep later that night. Exposing your skin and eyes to sunlight upon waking helps increase your body’s production of serotonin. Roughly 12 hours later, that serotonin gets converted into melatonin to help prep your body for sleep as your bedtime approaches.
  • Don’t light up your night: Since darkness is your body’s cue to increase melatonin production, make sure your nighttime environment reflects what’s happening outdoors. Turn off bright overhead lights in favor of dim lamps where necessary. And try to steer clear of blue light, as it can be especially disruptive to melatonin production. Because avoiding blue light — which comes from the screens of our various electronic devices — is not always possible, get a pair of blue-light blocking glasses to wear at night, especially in the 90 minutes before your bedtime. The RISE app can remind you when to put on your glasses each night. In the app’s Energy tab, add the Blue-Light Blocking habit to your Energy Schedule.
  • Create a zero-light sleep zone: A pitch-black sleep environment is the best way to help your body maintain its natural melatonin levels during the night. Use an eye mask and blackout curtains or blinds. And because we have photoreceptors all over our skin, eliminating all light in your bedroom is crucial. Even the seemingly insignificant light coming from a nightlight or the glowing green numbers on your digital alarm clock can impede your ability to sleep. 

If you manage to get your light exposure perfectly timed, but you’re still having persistent sleep problems, you may want to seek medical advice to address any possible sleep disorders or other underlying health problems. And if your doctor recommends melatonin as a sleep aid, be sure to do your homework to determine your best course of action.

Can Melatonin Supplements Be Useful? 

person taking medications

While a melatonin dietary supplement is no substitute for maintaining good sleep hygiene habits to support the body’s natural melatonin production, in certain situations, getting a little exogenous melatonin from a bottle can be useful. 

According to the Mayo Clinic, melatonin may help alleviate the symptoms of jet lag for people attempting to adjust their sleep patterns to different time zones. 

There is anecdotal evidence that suggests melatonin supplements may help shift workers sleep during the day when working night shifts. But a report published by the National Institutes of Health (NIH) found that the evidence was based on small studies whose results were inconclusive. Light therapy has proven to be a more reliable way to improve sleep outcomes for shift workers facing high circadian disruption. 

Melatonin supplements may be more helpful in correcting moderate circadian misalignment. For example, if you’re a night owl looking to shift your sleep-wake cycle to that of a morning person, a supplement can help  reset your sleep schedule. Evidence suggests that taking 5 mg of melatonin five hours before your DLMO can move evening melatonin production up by 1.5 hours and make it easier to fall asleep earlier.

Answers to FAQs About Melatonin Supplements

If you are considering melatonin supplements, here are some things you'll want to know.

What Are the Different Forms of Melatonin Supplements?

Some melatonin dietary supplements are made from animal glands, and others are made synthetically. Usually consumed as tablets, capsules, or liquids, melatonin is also available in gummies, patches, creams, and sprays. 

How Long Does Melatonin Take to Work? 

Different forms of exogenous melatonin are absorbed at different rates. As a rough estimate, melatonin in pill form can begin to take effect within 30 minutes. But it may take as little as 20 minutes or as long as two hours to kick in.

How Long Does Melatonin Last?

Depending on body weight, dosage, and supplement form, exogenous melatonin stays in your system anywhere from four to eight hours. Melatonin has a half-life — the time it takes the body to metabolize half of a dose of a medication or supplement — of approximately 20-50 minutes. On average, it takes four to five half-lives for the body to eliminate a melatonin supplement. But specially formulated slow-release supplements will last longer than immediate release forms. 

Are There Side Effects, and Can You Overdose on Melatonin Supplements?

Because melatonin is not regulated by the Food and Drug Administration (FDA), there are no official dosing guidelines. Though you won’t find recorded cases of lethal melatonin overdoses, taking high doses of exogenous melatonin increases your chance for experiencing common side effects such as headaches, nausea, dizziness, and daytime sleepiness. Although less common, some people may experience unpleasant side effects such as anxiety, depression, abdominal pain, and joint pain — or more serious side effects like tremors, seizures, and allergic reactions. 

Are Melatonin Supplements Safe?

Although melatonin supplements are often considered less habit forming than other common sleep aids, they’re not for everyone. Women who are pregnant or breastfeeding, transplant recipients, and people with certain conditions — diabetes, high blood pressure, seizure disorders, bleeding disorders, or depression — should consult a physician or health care professional before using melatonin supplements.  

Likewise, individuals on certain medications should avoid melatonin supplements, as they may reduce the medication’s efficacy or cause potentially harmful interactions. Prescription and over-the-counter medications that should not be taken in combination with melatonin include blood pressure and diabetes medications, certain contraceptives, immunosuppressants, anticoagulants (blood thinners), anticonvulsants (anti-seizure medications), and some depression medications. 

Although we can buy exogenous melatonin in unregulated over-the-counter supplements in the United States, the fact that other countries — including the United Kingdom — require a prescription for melatonin is a reason to give it some serious consideration before popping open a bottle of melatonin pills. Not enough is known about the long-term effects of taking melatonin, especially at high doses. 

Starting with the lowest dose is the best way to reduce your chances of developing unwanted side effects, but even that can be challenging and confusing. 

A 2017 study found that the contents of melatonin supplements are often dramatically different from what’s listed on the label. The actual melatonin content in the 16 brands tested ranged from 83% less to 478% more than the amount advertised on the label. So you may be taking a much lower dose or a significantly higher dose than you were led to believe.

What’s the Best Form of Melatonin With the Fewest Side Effects? 

To avoid the cost, dosing issues, and possible side effects of melatonin supplements, focus on supporting your body’s natural melatonin production by being strategic about the timing of your light exposure. 

The Best Source for Melatonin? Your Own Body

Melatonin plays an important role in keeping your sleep schedule in line with your circadian rhythm. Getting sleepy at the right time will help you get the sleep you need to maximize your next-day energy levels and perform at your best. But not all melatonin is created equal. You might say that melatonin supplements and the natural melatonin your body makes are as different as night and day. 

Supplements may be beneficial in certain situations, but otherwise, you don't actually need to take melatonin since your body produces it naturally. Plus, the version produced in your own brain is free, and you don’t have to worry about side effects, labels, or dosing confusion. To capitalize on its sleep-enhancing power, it’s vital to be strategic about getting light at the right time of day and to go to bed during your Melatonin Window.

Ultimately, whether you take advantage of your body's natural melatonin or take supplements, it's all about meeting your sleep need, which is the best thing you can do to achieve your potential each day. The RISE app can help you adopt good sleep hygiene habits so you can meet your sleep need for better daytime energy levels.

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About Rise
Rise is the only app that unlocks the real-world benefits of better sleep.

Instead of just promising a better night, we use 100 years of sleep science to help you pay down sleep debt and take advantage of your circadian rhythm to be your best.

Over the past decade, we've helped professional athletes, startups, and Fortune 500s improve their sleep to measurably win more in the real-world scenarios that matter most.

Rise Science is backed by True Ventures, Freestyle Capital, and High Alpha; investors behind category winners Fitbit, Peloton, and Salesforce Marketing Cloud.

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