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How Much Melatonin Is Too Much and Can You Overdose?

Experts recommend small doses of 0.3 mg to 1 mg of melatonin. Large doses can cause side effects, mess up your body clock, and haven’t been well researched.
Written by
Jeff Kahn, M.S., Rise Science Co-Founder
Reviewed by
Jamie Zeitzer, PhD, Rise Science Scientific Reviewer
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We bring sleep research out of the lab and into your life. Every post begins with peer-reviewed studies — not third-party sources — to make sure we only share advice that can be defended to a room full of sleep scientists.
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Updated Regularly
We regularly update our articles to explain the latest research and shifts in scientific consensus in a simple and actionable way.
Man taking melatonin supplements before bed

How Much Melatonin Is Too Much? 

  • There’s no official upper limit for how much melatonin is too much. But in general, experts recommend sticking to small doses of 0.3 mg to 1 mg of melatonin. 
  • Large doses can increase your risk of side effects, they haven’t been as well researched, and they can push back your sleep-wake cycle, making it harder to sleep the next night. 
  • If you’re taking melatonin supplements, the RISE app can tell you the best time to take them to make them more effective. Plus, as you should only take melatonin short term, RISE can guide you through 20+ daily behaviors to help you sleep without melatonin.

Melatonin supplements are a synthetic version of the hormone we make in our pineal gland. But just because it’s natural, that doesn’t mean taking large doses is safe, advised, or even necessary. 

Below, we’ll cover how much melatonin is too much, whether you can overdose, and how much to take exactly. 

Advice From a Sleep Doctor

Advice From a Sleep Doctor

“There’s no agreed maximum limit for melatonin, but you should stick to small doses. Even if it’s safe to take large doses of melatonin, you can disrupt your sleep schedule and larger doses aren’t necessarily more effective than smaller doses. I usually recommend taking a 0.3-to-1-mg dose of melatonin only when necessary, like when treating jet lag.”

That’s what Rise Science sleep advisor and medical reviewer Dr. Chester Wu, who is double board certified in psychiatry and sleep medicine, advises.

How Much Melatonin Is Too Much? 

There’s no set amount of melatonin that’s too much. In general, experts recommend taking no more than 1 mg of melatonin, and many recommend taking much smaller doses. Small doses of 0.3 mg to 0.5 mg have been shown to be effective and are less likely to make you groggy the next day or push back your next night’s sleep.

“Unlike other drugs like painkillers, for example, larger doses of melatonin aren’t more effective than smaller doses,” says Dr. Jamie Zeitzer, Co-Director of the Center for Sleep & Circadian Sciences at Stanford University and one of our sleep advisors. “In contrast to other drugs, taking too much melatonin probably won’t cause any serious health issues, but it can backfire and have the opposite effect you’re looking for, causing daytime grogginess and trouble sleeping the next night.” 

For example, some research shows 0.5 mg of melatonin can be just as effective as 5 mg for treating jet lag, and doses larger than 5 mg appear to be no more effective. 

Many studies looking into large doses of melatonin compare it to a placebo, not a lower dose, so it’s hard to tell what the lowest effective dose is.

Plus, how much melatonin is too much may be individual. It can depend on your age (older adults may need less), weight, and how sensitive you are to the side effects of melatonin.

You want to take as small a dose as you can because high doses of melatonin can: 

  • Increase your risk of side effects: You might feel groggy when you wake up and experience side effects like nausea, dizziness, or sleepiness during the day when you don’t want it (like when driving or at work). 
  • Push back your circadian rhythm: Taking melatonin in the morning can push back the timing of your circadian rhythm, meaning your body wants to sleep later than usual. This is ideal if you’re crossing time zones or prepping for night shifts, but not so ideal if you’re trying to sleep normally. This pushing back of your circadian rhythm can happen accidentally if you take too much melatonin in the afternoon or evening or during the night and wake up with high levels of it still in your system the next morning. 
  • Potentially cause health problems: Most clinical trials on melatonin study 2-mg doses so more research is needed into the safety and long-term effects of higher doses. 

Some experts say anything above a physiologic dose of melatonin is too much. A physiologic dose is a dose that’s equivalent to what your body produces naturally. Your body makes about 10 to 80 micrograms of melatonin a night (or about 0.01 mg to 0.08 mg). Doses of about 0.3-mg are generally considered physiologic. 

Larger doses than what’s found in the body are known as pharmacologic doses or supraphysiologic doses. These include the 5 mg, 10 mg, and 20 mg doses you can buy over the counter. 

Experts say you don’t need these supraphysiologic doses. 

“While melatonin is considered safe for most people, you may only need a low dose of it,” says Dr. Zeitzer. “In most cases, I’d recommend taking a small dose of 0.3 mg of melatonin and only in the short term.” 

It can also be hard to tell how much melatonin you’re taking exactly. A 2017 study found the amount of melatonin in supplements varied from 83% less to 478% more than what was advertised on the label. The U.S. Food and Drug Administration (FDA) classifies melatonin as a dietary supplement, so there aren’t many rules and regulations. You may think you’re taking a low dose, but it’s hard to know for sure. Plus, different formulations of melatonin — like gummies and sprays — can contain different doses.

Heads-up: Taking melatonin every night is also considered “too much” for most people. It’s generally safe for short-term use, like when adjusting to jet lag, not every night to fall asleep or to treat sleep issues. There are no set guidelines here either, but in general, you should only take melatonin until you’re adjusted to a new sleep schedule— which may be just a few days. Improve your sleep hygiene (more on that soon) and speak to a sleep specialist or doctor if you have trouble sleeping. If melatonin is the best treatment, they can prescribe the right amount of melatonin for you and tell you how often to take it. 

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Side Effects of Melatonin

The side effects of melatonin include:

  • Headaches
  • Nausea 
  • Dizziness
  • Daytime sleepiness  
  • Allergic reactions
  • Abdominal pain
  • Vivid dreams 

Melatonin isn’t considered addictive and you probably won’t develop a tolerance to it.

What Not to Take With Melatonin

Speak to a healthcare provider before taking melatonin if you’re on medication such as: 

  • Epilepsy drugs
  • Anticoagulants (blood thinners)
  • Immunosuppressants
  • Hormonal birth control 

When Not to Take Melatonin 

You may not be able to take melatonin when: 

  • Pregnant 
  • Breastfeeding 
  • You’ve received a transplant 
  • You’ve got a health condition like diabetes, depression, or high blood pressure
  • You’ve got a sleep disorder (melatonin may not be best for insomnia) 

Get medical advice before taking melatonin. Your healthcare provider can tell you whether it’s safe for you, what the upper limit is for you, and whether other treatments are more effective. 

How Much Melatonin Is Too Much for Kids? 

There are no set guidelines for how much melatonin is too much for kids. You should only give children melatonin on the advice of a healthcare professional who can prescribe an exact dose. 

The American Academy of Sleep Medicine says there’s little evidence that melatonin can treat insomnia in healthy children (or anyone for that matter). Habit and schedule changes may be better. 

Melatonin use among kids has increased and it can be dangerous. A 2023 study found calls to US Poison Control Centers for pediatric melatonin ingestions increased by 530% from 2012 to 2021. They were linked to over 4,000 hospitalizations and two deaths.

A 2023 paper says there’s limited data on the dosage of melatonin for young people. So the right dose could vary with age, and supplements may affect adolescents and young people differently — 2023 research found young adults had lower morning cognition after taking melatonin the night before.

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Can You Overdose on Melatonin? 

Most experts agree you probably can’t overdose on melatonin, but more research is needed. 

Melatonin’s half-life (the time it takes your body to metabolize half a dose) is about 20 to 45 minutes. So your body should be able to process large doses before you experience serious melatonin side effects. 

We’ve covered how long melatonin lasts here.

One study found there were no adverse effects from 100 mg of melatonin up to seven hours later (and this amount didn’t make participants fall asleep, either!). The study was small though — only 12 people! Experts do not recommend doses anywhere close to this. 

Melatonin Overdose Symptoms  

While you can’t technically overdose and taking a large dose may not be life-threatening, you may experience more serious side effects such as: 

  • Vomiting 
  • Dizziness 
  • Stomach cramps 
  • Pushing back your circadian rhythm  
  • Anxiety
  • Depression
  • Joint pain 
  • Tremors
  • Seizures

Seek medical attention if you’re experiencing unwanted side effects.  

How Much Melatonin Should I Take? 

There are no set guidelines for how much melatonin to take. Experts recommend starting with as low a dose as possible. Higher doses aren’t necessarily more effective than lower doses, and how sensitive you are to melatonin and how high your natural levels are will vary from others. How much melatonin you should take may depend on what you’re using it for and when you’re taking it. If you’re taking it to fall asleep each night, you may not need to take any at all. 

In general, here’s a rough guide to how much melatonin to take to: 

  • Get over jet lag: 0.3 mg to 1 mg of melatonin. How much you need to take depends on your direction and duration of travel. 
  • Shift your sleep schedule: 0.3 mg to 1 mg of melatonin. 
  • Adjust to shift work: 0.3 mg to 1 mg of melatonin. Shift workers may be better off with other treatments, like light therapy, to avoid the risk of drowsiness at work.
  • Fall asleep faster: None at all or as small a dose as possible. Melatonin isn’t that effective as a sleep aid when taken when your natural levels of melatonin are already high (i.e. in the evening or at night). 
  • Treat insomnia or other sleep disorders: None unless prescribed by a healthcare provider. Speak to a doctor to get your prescribed dose. Other treatments may work better. 

If you do decide to take melatonin, we recommend Thorne and USP tested as reputable brands. Start with the lowest dose possible and only increase if needed, but don’t cut pills in half to decrease your dose. 

We’ve covered more on how many mg of melatonin to take here.

When it comes to the effectiveness of melatonin, when you take it can matter more than how much of it you take.

In general: 

  • To fall asleep earlier than usual: Take melatonin four to five hours before the time you want to feel sleepy.
  • To fall asleep later than usual: Take melatonin at your usual wake-up time.
  • To fall asleep at bedtime: Take melatonin 30 to 60 minutes before bed (but know that it’s not as effective at this time). 

We’ve covered how long before bed to take melatonin here.

RISE can tell you the best time to take melatonin supplements to fall asleep earlier.

RISE app screenshot showing melatonin supplement time reminder
The RISE app can tell you the best time to take melatonin.

Is it Safe to Take 10 mg of Melatonin? 

It may not be safe to take 10 mg of melatonin. More research is needed. In general, experts recommend taking much lower doses of 0.3 mg to 1 mg of melatonin. Taking high doses increases your risk of side effects and they can push back your circadian rhythm, resulting in sleep problems the next day. 

Is it OK to Take 20 mg of Melatonin? 

It may not be OK to take 20 mg of melatonin. Many experts recommend taking only 0.3 mg to 1 mg of melatonin. More research is needed on larger doses. They may not be safe and you may inadvertently push back your circadian rhythm the next day.

How Much Melatonin Does the Body Produce?

It’s thought the body produces about 10 to 80 micrograms of melatonin per night, which is equivalent to about 0.01 mg to 0.08 mg. Everybody produces a different amount of melatonin, however, and the amount of melatonin you produce may be affected by doing shift work, being overweight, or having a medical condition. You may not produce less with age, but older adults often have lower melatonin due to medical conditions. 

Certain behaviors can also affect how much melatonin your body produces day to day, such as:  

  • Light: Light has the largest impact on melatonin. Research shows room light exposure during normal sleep hours can suppress melatonin levels by more than 50%.
  • Alcohol: One study found after a moderate dose of alcohol an hour before bed, melatonin was down by 19% about three hours later. 

To make sure your body can make the melatonin it needs, follow RISE’s 20+ sleep hygiene reminders. These are timed to your own circadian rhythm and include when to get and avoid bright light and when to stop drinking alcohol each day. 

We’ve covered how to increase melatonin naturally here, and how to fall asleep without melatonin supplements here. 

RISE can also tell you when your body’s rate of melatonin production is at its highest — look out for your Melatonin Window. You’ll have an easier time falling asleep if you head to bed during this window.

RISE app screenshot showing sleep hygiene habit reminders
The RISE app can tell you when to do 20+ sleep habits.

RISE users on iOS 1.202 and above can set up their 20+ in-app habit notifications here

Expert tip: Want to improve your sleep? The first step is finding out how much of it you need. Use RISE to find out your unique sleep need — it’s different for everyone. When looking at the sleep needs of 1.95 million RISE users aged 24 and up, we found it ranged between five hours and 11 hours 30 minutes.

The RISE app can tell you how much sleep you need
How much sleep RISE users need.

RISE users on iOS 1.202 and above can view their sleep need here

Take As Low a Dose of Melatonin As Possible 

There are no hard-and-fast rules when it comes to melatonin doses, but many experts agree anything over 1 mg can be too much. Many recommend smaller doses than that. Small 0.3-mg and 0.5-mg doses have been shown to be effective and they’re less likely to leave you feeling groggy the next or push back your body clock.

If you do take melatonin, RISE can tell you the best time to take it. You can also follow RISE’s 20+ personalized sleep hygiene habit reminders each day. Some of these habits help boost your body’s natural production of melatonin, and they can all help you fall asleep faster and wake up less often, whether you’re taking melatonin or not. 

RISE users notice the benefits of a good night’s sleep: “After figuring out how I should sleep with this app, I felt a lot better and my health is better too!” Read the review.

We’ve found 80% of RISE users get better sleep within five days. 


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