Can I Take Melatonin Every Night? You Probably Don’t Need It

Melatonin may help you fall asleep, but should you take it every night? The science says it’s safe short term, but the jury’s still out on long-term use.
Reviewed by
Jeff Kahn, M.S., Rise Science Co-Founder
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Woman thinking about taking melatonin at night

We’ve all been there. You crawl into bed after a long, hard day and…nothing. You simply can’t fall asleep. You check the time, counting down the hours until your alarm clock rings, willing your mind and body to just switch off. 

Sound familiar? You’re not alone. Many of us have trouble falling asleep and more people are turning to melatonin supplements to help. One study found that in 2018, Americans were taking more than double the amount of melatonin they were a decade before.

Unlike traditional sleep aids, melatonin is made naturally by the brain to help us sleep. So, it sounds like it’s the safest option — and for the most part, it is. There’s no risk of overdosing or addiction, and it has far fewer side effects than traditional sleeping pills. 

Research shows it’s effective at promoting sleep and shifting your circadian rhythm (more on that soon) and it’s safe when used short term. However, it’s still a powerful hormone — just like testosterone or estrogen — so can you take melatonin every night? And even if it’s safe, should you take it nightly? 

In this blog post, we’ll cover what the science says about taking melatonin supplements long term and how, with a few simple lifestyle tweaks, you can optimize your natural melatonin production to fall asleep without relying on supplements every night. 


How Does Melatonin Work?

Melatonin is a hormone that primes your body for sleep. As long as it’s dim enough, a few hours before your biological bedtime, the pineal gland in the brain will start producing melatonin. This moment is called the dim light melatonin onset (DLMO).

But this production is easily thrown off by many external factors — the biggest of which is light exposure. If you get too much light in the evenings — think from your TV, phone, or bright overhead lighting — your brain can’t produce melatonin effectively, making it harder for you to fall asleep. 

By taking melatonin supplements, you’re adding to your natural levels of melatonin, tricking your brain into thinking it’s sunset, helping it wind down and start preparing for sleep. Supplements are especially useful to take when you wouldn’t naturally be producing melatonin, such as during the day if you’re a night shift worker or when you’re trying to adjust to a different time zone. 

But, most of the time, supplements aren’t needed for daily use as your brain — with the right behaviors — can make all the melatonin it needs for a good night’s sleep. 

Is it OK to Take Melatonin Every Night to Sleep?

Many people turn to external sources of melatonin to help them drift off, but is this safe to do night after night? Opinions are divided. Here’s why. 

Limited Long-Term Studies 

A 1997 study stated there is no published data on the use of melatonin for longer than six months — and things haven’t changed much since then. A 2015 paper, for example, looked at several studies and concluded there was very limited data about long-term melatonin use.

In some long-term studies, participants only experienced mild side effects when taking melatonin compared to those taking a placebo. They reported side effects such as dizziness and headaches after three months of use. 

But, most of the time, studies are only one to seven days long. So while short-term use appears to be safe, there’s simply not enough research to say what the long-term effects could be. 

Long-term melatonin use in children and adolescents needs further study, and there isn’t enough data to say if it’s safe for those who are pregnant or breast-feeding at all, so these groups should avoid supplements altogether. 

Potential Long-Term Health Impacts 

A 2019 study suggested long-term melatonin use in children could delay puberty. But, as with many melatonin studies, the researchers ultimately concluded the research was limited and there wasn’t enough evidence to say either way. 

Research suggests taking a relatively small dose of melatonin (2 mg) for one month doesn’t cause any changes in anterior pituitary hormones, except for prolactin. Another study found melatonin supplements increased prolactin levels, which can lead to liver, kidney, and hormone problems. 

In fact, taking a large dose of melatonin (80 mg) was shown to substantially increase prolactin secretion, and as high levels of prolactin are associated with infertility in both men and women, it’s another reason you may want to stick to smaller doses for the short term until more research into long-term use is done. 

Protecting Your Brain’s Natural Production of Melatonin 

Some experts think taking supplements may interfere with your natural melatonin production, as you’re signaling to your brain that it doesn’t need to make its own supply of the hormone anymore. While a short-term study of seven days didn’t show this happening, long-term studies looking into this still need to be done. 

Treating Sleep Disorders 

Melatonin has been shown as an effective way to treat sleep disorders like insomnia and delayed sleep-wake phase disorder. But even then, it’s used as a short-term treatment. 

For example, in the UK, where melatonin is only available by prescription, the supplement is usually prescribed for one to four weeks, and occasionally up to 13 weeks. Some healthcare providers may even recommend taking melatonin two to three times per week, instead of every night. 

However, while some studies say melatonin may be a useful treatment for insomnia, especially in older people, other research suggests it doesn’t make enough of a difference to be a recommended treatment. Some experts even think it could make insomnia worse, although again, there’s not much evidence to support this either way. 

So, if you want to use melatonin to treat sleep problems, it’s always best to get medical advice before doing so, as not only is every treatment plan different, there may be a better sleep medicine out there for you.

It Might Not Work Long-Term

While short-term use has been shown in some studies to help those with sleep issues, there is some evidence to show melatonin may not even work long term. In a 2013 study, participants reported improved sleep after taking supplements for three months, but these improvements weren’t felt at the 12 month mark. 

However, as with many studies on melatonin, these participants had a health condition, and there’s not a lot of data on long-term use in healthy participants. 


While there doesn’t seem to be a risk of addiction, it’s all too easy to start feeling like you need to take melatonin for a good night’s sleep. Perhaps you take it for a few nights before stopping, but on the first night without a supplement, you worry so much about falling asleep that the stress keeps you up and disturbs your sleep. 

Unregulated Supplements 

Melatonin in countries like the UK and Australia is only available by prescription, but it’s unregulated in the US and available over the counter. The Food and Drug Administration (FDA) classifies them as a dietary supplement, so there are no real guidelines around how much you should take, or and how long you should take it for.  

In fact, one concern about the safety of melatonin is that you may not even know how much you’re taking. A 2017 study tested brands of supplements and found they contained 83% less to 478% more melatonin content than advertised on the label. 

So, even if you think you’re taking a small dose each night, you may be taking much more, increasing your risk of side effects in both the short and long term. We covered how much melatonin is too much here. 

You Can Probably Improve Your Sleep Naturally 

Melatonin doesn’t work in the same way traditional sleep aids do. Instead of putting you to sleep straight away, it tricks your brain into thinking it’s sunset, priming it for sleep a few hours later. While some people feel drowsy 20 minutes after taking melatonin, it can take a few hours to feel the effects. So, if you’re tossing and turning at 1 a.m., melatonin isn’t the answer. We covered other reasons why melatonin supplements may not work for you here.

Plus, if low melatonin levels are the reason you struggle to fall asleep, there are natural ways you can boost your brain’s production of the hormone, instead of turning to external sources. We’ll cover those below. 

How Long Can You Take Melatonin Every Night?

There are times when melatonin comes in handy, such as when you’re: 

  • Treating jet lag
  • Shifting your sleep schedule 
  • Adjusting to shift work 

You should combine supplements with good sleep hygiene for the best results. And when you do turn to supplements, we recommend Thorne and USP tested

As timing is everything when it comes to supplements, the RISE app can tell you when to take them based on your circadian rhythm, and send you a reminder so you don’t take them too late. 

We’ve already covered how much melatonin you should take in these cases, but how long should you take it for? Here’s what the science says: 

Jet Lag 

Melatonin has been shown as an effective way to recover more quickly from jet lag. That’s because the supplement is chronobiotic, or something that can shift your circadian rhythm. Taking it early in the morning can help you stay up later, if you’re flying west, and taking it a few hours before you want to sleep will help you fall asleep earlier, after flying east. 

It’s generally recommended to take melatonin supplements a few days before your flight, and then until you’re adjusted, which should be two to three days after arriving at your destination. 

Advice varies, however. For example, the National Health Service (NHS) in the UK recommends taking melatonin for only five nights maximum when treating jet lag. 

Shifting Sleep Schedule 

There may be times in life when you need to reset your sleep schedule — like if you’re a night owl who wants to become a morning person. Melatonin can help you make the shift by helping you fall asleep at a time when you wouldn’t naturally be tired. 

The advice here would be the same as if you were adjusting to a different time zone — use melatonin as a short-term aid until you’re adjusted. Then rely on sleep hygiene — like light exposure as well as meal and exercise timing — to keep your circadian rhythm running at the earlier time. 

Adjusting to Shift Work 

If you’re a shift worker, you may need to quickly flip your days and nights, and it can feel impossible to suddenly be alert through the night and fall asleep in the day. That’s where melatonin may help. 

One study looked at police officers who took melatonin for a total of 11 days to help them sleep in the morning after a night shift, and then at night once the night shifts were over. They didn’t experience any side effects, and they said they slept longer and reported better sleep quality (although sleep scientists still don’t agree on a definition for sleep quality). However, the study was very small — only eight people! 

In fact, the National Institute of Health (NIH) found many studies looking into melatonin use and shift workers were small and had inconclusive results. Light therapy may actually be a more effective tool for shift workers. 

So again, the recommendation here would be to take melatonin only short term until you’re adjusted to your new sleep-wake cycle, and look into alternative treatments — like light therapy — to help if you’re constantly switching. 

However, not everyone agrees melatonin is suitable for shift workers. Josephine Arendt from the University of Surrey, for example, doesn’t because of the risk of accidentally making yourself sleepy or impacting your performance at work if you take supplements at the wrong time. 

“I strongly advise shift workers and flight crew members not to self-medicate with melatonin at present,” she wrote in the Journal of Biological Rhythms. “That is, until we can be certain of correct timing.” 

What are the Side Effects of Melatonin?

The side effects of long-term melatonin use are still unknown. Short-term use can come with side effects like:

  • Headaches 
  • Nausea 
  • Dizziness 
  • Depression 
  • Tremors
  • Low blood pressure  
  • Allergic reactions 
  • Drowsiness when you don’t want it — like during the day or when driving 

Start with a smaller dose of melatonin to see if it works, as higher doses come with a higher risk of side effects. 

How Can I Boost Melatonin Naturally?

RISE app screenshot showing you when to get and avoid bright light.
The RISE app will tell you when to get and avoid blue light to optimize your circadian rhythm.

Want the sleep-boosting benefits of melatonin without taking a supplement night after night? With a few key behaviors, our brains can produce all the melatonin we need for natural healthy sleep. Here’s what to do. 

Sleep Hygiene

Sleep hygiene refers to the set of behaviors you can do throughout the day to help you sleep come nighttime. These healthy sleep habits include:

  • Get natural light each morning: Getting light exposure first thing will suppress melatonin production, setting up your circadian rhythm to ensure the hormone can be made later that evening. Aim for at least 10 minutes of natural sunlight, or 30 minutes if it’s cloudy or you’re getting light through a window.  
  • Get natural light throughout the day: Four to five hours of natural light exposure in the day can decrease how sensitive you are to bright lights come nighttime. If you can’t get outside for that long, try working by a window.  
  • Make your evenings dark: As darkness triggers melatonin production, and therefore sleepiness, dim the lights and put on blue-light blocking glasses 90 minutes before bed. The RISE app can tell you the best times to get and avoid blue light to help your brain make melatonin when you want it to. 
  • Keep your bedroom dark: Ensure your brain can effectively produce melatonin all night long by using blackout curtains and wearing an eye mask. If you wake up in the night to use the bathroom, use your phone flash light, instead of turning on the lights. 
  • Avoid alcohol too close to bedtime: Even one drink can suppress melatonin production. The RISE app can tell you the best time to have your last drink based on your circadian rhythm so as to not disturb sleep. 

Circadian Rhythm 

RISE app screenshot showing your melatonin window which can tell you the best time to go to sleep.
The RISE app can tell you the ideal time to go to bed each night. 

Your circadian rhythm is your internal body clock. It runs on a roughly 24-hour cycle and dictates when your body feels awake, sleepy, and when it produces certain hormones, including melatonin. 

Being strategic with light exposure can help, but you can also sync your schedule with your circadian rhythm to have an even easier time feeling sleepy when you want to. 

For example, there’s a time of night when your brain will be producing the most melatonin it will all night. In the RISE app, this is called the Melatonin Window. If you go to sleep in this roughly one-hour window, you’ll be taking advantage of your natural melatonin supply and have a much easier time falling asleep compared to if you went to bed at other times of night. 

Use RISE to Harness Your Natural Melatonin 

Melatonin supplements are great for some as a short-term sleep aid — like when treating jet lag or shifting your sleep schedule — but the jury’s still out on whether they’re safe to use long term. 

The best way to fall asleep easily, night after night? Using the safest form of melatonin, the kind your brain makes.

The RISE app can help you practice good sleep hygiene and sync up with your circadian rhythm. It can tell you when exactly you should be getting and avoiding blue light, so your brain can make all the melatonin it needs for a good night’s sleep. And when melatonin supplements are the answer, RISE can tell you the ideal time to take them based on your own circadian rhythm.

All of Your Sleep and Melatonin Questions Answered:

Summary FAQs

Is it OK to take melatonin every night long-term? 


There isn’t much research into long-term melatonin use. Short-term use appears to be safe, so try to limit melatonin to a few days at a time, and then get back to harnessing your natural melatonin production.

Can I take 5mg, 10mg of melatonin every night? 


While more research needs to be done to find the ideal dose, most of the time, you don’t need to take more than 5 mg of melatonin. In fact, even 0.5 mg to 1 mg doses have been shown to be effective.

Melatonin side effects 

 Melatonin side effects include headaches, nausea, dizziness, and more serious things like anxiety, depression, tremors, and allergic reactions.

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