How Much Melatonin Is Too Much? It’s Lower Than You Think

How do you know how much melatonin is too much? We say, most of the time, you don’t need to take any melatonin supplements at all.
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Jeff Kahn, M.S., Rise Science Co-Founder
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Man taking melatonin supplements before bed

You may have tried melatonin supplements to try to get better sleep, but found small doses aren’t doing the trick. So, naturally, you start reaching for more the next night, and then more the night after that. But how much melatonin is too much? Most of the time, we say any extra melatonin you take is too much. Hear us out! 

Melatonin is a hormone that’s naturally produced in the brain’s pineal gland to promote sleep. If everything’s working correctly, you’ll naturally make enough for a good night’s sleep and supplements simply aren’t needed. If you’re having trouble sleeping, a few lifestyle tweaks — like practicing good sleep hygiene and living in sync with your circadian rhythm — can ensure your brain produces all the melatonin it needs. 

However, there are a few situations when melatonin supplements come in handy, like when adjusting to jet lag, shift work, or moving your sleep schedule. But even in these cases, you need much less melatonin than you probably think. Read on to learn how you can stop worrying about how much melatonin to take (by harnessing your natural supply instead) and how much melatonin is too much in those situations when you do need to take it.  

The Trend of Taking More (and More) Melatonin 

There's no doubt about it: melatonin use is on the rise. According to one study, the number of Americans taking melatonin in 2018 was quadruple the number who were taking it a decade earlier. And the supplement has only gotten more popular since. As it’s produced naturally in the brain, it’s easy to view melatonin like a vitamin tablet you take to get more of something you’re deficient in. But just because it can be produced naturally, doesn’t mean supplement versions are risk free. 

In the UK and Australia, for example, melatonin is only available by prescription. But in the US, it’s available over the counter and unregulated. It’s marketed and sold as a natural remedy for better sleep, and more of us are reaching for it night after night. But for most of us, a few simple behaviors, and a tool like the RISE app, can ensure your brain naturally produces enough melatonin to fall asleep, so you can reach your full potential each day, all without any supplements at all.  

How to Make Sure Your Brain Produces All the Melatonin it Needs 

RISE app showing your energy peak and dip times
The RISE app will tell you the best time to go to sleep to harness your natural melatonin. 

The best way to avoid taking too much melatonin is to not take any at all and instead harness your brain’s natural melatonin production. You can do this by focusing on two simple things: circadian rhythm and sleep hygiene. 

Your circadian rhythm is the roughly 24-hour internal body clock that controls when you feel sleepy, awake, and when your brain does things such as produce melatonin. There’s a time of night when your natural rate of melatonin production peaks — in the RISE app this is called the “Melatonin Window.” If you go to sleep in this one-hour window, you’ll have a much easier time falling asleep. 

RISE calculates your circadian rhythm each day — based on things like your inferred light exposure and previous night’s sleep — and gives you a one-hour ideal bedtime to aim for. 

Sleep hygiene, on the other hand, is a set of behaviors you can do during the day, evening, and at nighttime to set yourself up for a good night’s sleep. Many of these behaviors include avoiding things that suppress melatonin production. Here’s what you can do: 

  • Get natural light when you wake up: Light exposure tells the brain that it’s daytime and stops it making melatonin. Get 10 minutes of natural light as soon as possible after waking up to feel alert and set up your circadian rhythm correctly, so you’ll produce melatonin later that evening. 
  • Get natural light during the day: Studies suggest getting four to five hours of natural light in the day could make you less sensitive to bright artificial lights come nighttime. Aim to get this light from being outside, or sit by a window if that’s not possible. 
  • Avoid light in the evenings: Darkness triggers melatonin production, so dim the lights and put on blue light blocking glasses about 90 minutes before bedtime. We dive more into the science of how blue light blocking glasses work here.
  • Make your bedroom as dark as possible: Keep melatonin production high as you’re drifting off and in the first few hours of sleep by using blackout curtains and wearing an eye mask
  • Avoid alcoholic drinks close to bedtime: We know a nightcap can help you feel drowsy at first, but alcohol disrupts sleep through the night and even one drink can suppress melatonin production

The RISE app can tell you the best time to do these sleep hygiene behaviors each day based on your circadian rhythm. 

When You Should Take Melatonin 

So we’re obviously big fans of harnessing natural risk-free melatonin — the type your brain makes — but there are a few times when taking supplements is useful. 

You should consider taking supplements when: 

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

How Much Melatonin to Take

We’ve covered in more detail how much melatonin to take in various situations, but generally, there’s rarely a need to take more than 5 mg of melatonin. In fact, research suggests a smaller dosage of melatonin (think 0.5 mg to 1 mg) may be just as effective as a larger one (3 mg).  

So to reduce the risk of side effects, we recommend starting with a low dose and only increasing to higher doses if necessary. Plus, keep melatonin use as a short-term fix, not something you rely on every night to get to sleep. 

Jet Lag 

Melatonin can help you adjust to a different time zone. In general, research suggests 5 mg melatonin supplements when taking eastbound flights and 1 mg for westbound flights. Studies show just 0.5 mg can be effective and anything over 5 mg doesn’t seem to be any more effective than 5 mg. 

Shift Work 

Research suggests 0.3 mg to 5 mg can help people fall asleep when they otherwise wouldn’t be producing melatonin — such as when a night shift worker wants to sleep during the day. 

Moving Your Sleep Schedule 

Studies show just 1 mg of melatonin may be enough to help shift your sleep-wake cycle — for example, if you’re a night owl trying to reset your sleep schedule to start waking up earlier. You can make this even more effective by getting light exposure early in the day.  

How Long Can You Take Melatonin For? 

It really depends on why you’re turning to supplements in the first place, but it’s generally agreed supplements are safe for short-term use. 

In the UK, for example, melatonin is usually prescribed to treat insomnia for only 1 to 4 weeks, and for jet lag it’s recommended to take it for up to five days. Studies recommend taking melatonin until you’re adjusted to jet lag, which may be even fewer days.

More research needs to be done on the long-term effects of melatonin use and to determine better guidelines for how long you can safely take it for, but we’d recommend only taking it for as short a time as possible and, most of the time, focusing on boosting your natural melatonin production instead. 

What Are the Side Effects of Melatonin? 

Melatonin can come with unwanted side effects like headaches, dizziness, stomach cramps, and unintended daytime sleepiness. More serious side effects include anxiety, depression, tremors, seizures, and allergic reactions. 

Studies suggest melatonin supplements may also increase the body’s production of prolactin — the hormone that enables milk production — in men, which can go on to cause hormone, liver, and kidney problems. 

Some experts even believe supplements may reduce your body’s natural production of melatonin. Although one study showed this didn’t happen after seven days of taking supplements, research on what happens with long-term use still needs to be done. 

On the plus side, there’s some evidence to show melatonin may help in the treatment of PCOS (polycystic ovary syndrome) and even female infertility. Although for men, one study showed melatonin may reduce sperm count and another showed it may protect it — so more research clearly needs to be done here, too. 

In general, melatonin is seen as much safer than traditional sleep aids. Taking melatonin hasn’t been linked to sleepwalking, and there’s not enough evidence to say it can cause bad or vivid dreams. It may help treat sleep problems like insomnia, diagnosed delayed sleep-wake phase disorder, and sleep problems among older adults — but all of this should be under the supervision of a healthcare professional. 

Can You Overdose on Melatonin? 

There doesn’t seem to be a risk of melatonin overdose. But the annoying answer is no one knows for sure — there’s simply not much data on the effects of taking high doses of melatonin. 

However, taking more than you wanted to is a real risk. A 2017 study found the amount of melatonin in supplements varied from 83% less to 478% more than advertised on the label. The US Food and Drug Administration (FDA) classifies melatonin as a dietary supplement, so there isn’t strict regulation. But it is generally agreed upon by experts that there’s no risk of abuse, dependence, or rebound effects from withdrawal from melatonin supplements. 

When You Shouldn’t Take Melatonin 

So we’ve covered that melatonin should be a short-term solution if you take it, but there are some cases when you really shouldn’t take melatonin at all. 

You should seek medical advice before taking melatonin supplements if you are pregnant, breastfeeding, a transplant recipient, or have a health condition like diabetes, high blood pressure, or a seizure or bleeding disorder. People with medical conditions like hepatic impairment (liver problems) or mental health concerns like depression should also speak to a doctor and potentially steer clear of melatonin, too. 

If you’re taking certain medications — like blood pressure and diabetes medications, certain contraceptives, immunosuppressants, anticoagulants (blood thinners), or anticonvulsants (anti-seizure medications) — you should avoid taking melatonin supplements as they may have harmful interactions

There’s also limited research into the effects of melatonin supplements on children and teenagers, so many experts do not recommend these groups using them. 

The Safest Amount of Melatonin to Take? None 

Opt for the cheapest, safest, and easiest form of melatonin by relying on your brain’s own natural production. To do this, use the RISE app to practice good sleep hygiene and go to sleep in your Melatonin Window. This will ensure you will have all the melatonin you need, without ever needing to worry about taking too much. In the rare cases where supplements are needed, take the lowest dose you can to reduce the risk of side effects.

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