How Long Does Melatonin Last in Your Body?

Written by Natalie Grigson, Writer

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In This Article

Discover the speed of melatonin absorption in the body, investigate if melatonin affects waking up, and find out how many types of melanin we have.

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If you’re thinking about taking melatonin to help you sleep, you probably have a few questions. How does it work? When should I take it? How long will it last in my system? 

Perhaps you’re wondering so that you can plan a time to take it at night without waking up groggy in the morning. You might also want to know how long it lasts in case you’re taking it for the first time and are worried you won’t like how it makes you feel. 

In this article, we’ll get into just how long melatonin takes to absorb and how long it lasts in the body, depending on the type of melatonin.

Learn more: Read our complete guide on melatonin. 

How Quickly Does the Body Absorb Melatonin?

The rate at which the body absorbs melatonin will depend on the type of melatonin you’re taking, along with your unique metabolism. Most people will take melatonin orally as a tablet, capsule, or gummy. 

If you’re taking standard, immediate-release oral melatonin, your melatonin levels will peak about an hour after administration¹. At this point, the amount of melatonin will be between 10 and 100 times higher than your body’s natural melatonin levels depending on the dose.¹ 

Oral melatonin is metabolized in the liver and its half-life is only about 40 minutes². The term “half-life³” refers to how long it takes for half of the active substance to be eliminated from the body.  Typically, it takes about 4-5 half-lives⁴ for most drugs to be removed fully from the body and no longer have any clinical effect. Therefore, melatonin will likely go through approximately 4-5 more 40-minute half-life cycles throughout the night.

The melatonin should be completely out of your system between four and eight hours after ingestion.¹ That said, the Mayo Clinic⁵ recommends not driving or using machinery within five hours of taking melatonin, so with this guidance in mind, melatonin may be eliminated closer to four or five hours. 

Either way, we advise consulting with your healthcare provider on this to ensure the timing of your melatonin is safe for any activities where you must be alert.

Explore our expert-selected picks for the Best Melatonin Supplements.

Immediate-Release Melatonin vs. Extended-Release Melatonin

Unless a melatonin supplement is labeled as extended-, sustained-, or prolonged-release, it is likely an immediate-release supplement. An immediate-release product means that all of the medication⁶ is released at once, rather than gradually. This type of formulation is absorbed and cleared from the body more rapidly than extended-release melatonin.⁶ 

Extended-release pills, on the other hand, “better mimic the naturally occurring melatonin” in the body because they release more slowly through the night. Additionally, extended-release melatonin takes longer to reach its peak concentration (about 1.56 hours) and takes longer to eliminate, with a half-life of 1.63 hours.⁶ 

The maximum concentration of extended-release melatonin is lower than that of immediate-release melatonin; however, extended-release pills seem to keep melatonin levels elevated for longer (about six hours) before they even begin to dip. Melatonin levels should return to baseline within nine hours after taking extended-release melatonin.⁶ 

This means that while immediate-release melatonin should help you fall asleep, extended-release melatonin may be better at helping you stay asleep through the night. It also means you may want to take immediate-release melatonin about one hour before bedtime and extended-release about an hour and a half or two hours before bedtime. 

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Does Melatonin Make It Hard to Wake Up?

Melatonin shouldn’t make it hard to wake up. As mentioned, it is eliminated from the blood while you’re sleeping, so somewhere between four and eight hours after you’ve taken the melatonin, it should no longer affect you.¹ 

That said, some people may experience morning grogginess⁷ with melatonin. If this happens to you, it may mean that you’re taking it too late at night, taking too high a dose, or taking a supplement that isn’t high quality and may contain ingredients not listed on the label. 

To avoid morning grogginess, make sure you’re taking melatonin at least one or two hours⁸ before your intended bedtime (never right before bed) and that you’re buying supplements that are USP-verified⁹. A USP verification means your melatonin supplements have been third-party tested and include the exact ingredients listed on the label. Not all supplements are third-party tested. Although USP-verified is considered the gold standard by some, it’s important to research the brand before purchasing to ensure their ethical and safety practices.

Even if a supplement is third-party tested (including USP-verified), you should still speak with your healthcare provider before using it. Keep in mind that with melatonin supplements, less can be considered more. Experts recommend sticking with a dose somewhere between 1 and 3 milligrams¹⁰, with a maximum recommendation of 5 milligrams for certain people.²

Learn More: Is Melatonin Bad for You? and Is it Safe to Take Melatonin Every Night?

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Types of Melatonin

Melatonin Pills

Pills can be either tablets or capsules¹¹ and can either come in immediate-release formulas or extended-release formulas. Any oral pills will pass through the digestive system¹² and are then processed in the liver. This means that some of the melatonin in the pill may be lost along the way before getting into your bloodstream.¹²

Melatonin Gummies

Gummies are sweet, soft chewables that can be a good fit for children taking melatonin or adults who prefer not to take melatonin in pill form. Like pills, melatonin gummies will pass through the digestive system and liver, losing some of the active ingredients along the way.¹² 

Liquid Melatonin

Liquid melatonin can be a good option for those who don’t like pills or want more freedom to specify their dose. You can take liquid melatonin by dropping it into your mouth with a dropper. This form of melatonin also passes through the digestive system and liver¹³ since it is taken orally, and the difference in absorption rates between liquids, capsules, and tablets seems to be marginal.

Melatonin Melts

Melts are dissolvable tablets that you can place either on your tongue, under your tongue, or between your gum and cheek. According to research, melatonin melts that are absorbed by the mucus membrane (also known as “oral transmucosal”) have been shown to put more melatonin into the bloodstream¹⁴ when compared to oral melatonin as it avoids first-pass metabolism. 

Patches

“Transdermal patches” are adhesive strips placed on the skin to deliver active ingredients. Research shows that melatonin transdermal patches tend to release the melatonin more slowly and steadily through the night, sort of like an extended-release pill might.¹⁴ These patches seem to be particularly effective¹⁵ for shift workers who need to sleep during the day, those with jet lag, and elderly people who wake up very early in the morning. 

Nasal Sprays

Nasal sprays may be a good option for people who dislike taking pills or who want a faster-acting, more bioavailable form of melatonin.¹⁴ Bioavailability refers to a substance’s ability to be absorbed and used by your body.

Since these sprays are delivered straight into the nose, they bypass the digestive tract and begin working more quickly. Research shows that of the various forms of melatonin, nasal sprays are absorbed the fastest and have the highest bioavailability – meaning, more of the melatonin actually makes it into your system.¹⁴

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Frequently Asked Questions