How Long Does Melatonin Take to Work?

Medically approved by
Dr Earim Chaudry
Last updated
13th March 2022

In 30 seconds

Melatonin is a natural hormone that helps your body maintain a healthy sleep-wake cycle. But many people take it as a medicine to help them sleep, particularly after short-term sleep disruptions such as jetlag or shift work. How long does melatonin take to work? Typically, about 1 to 2 hours, but it can work much more quickly – in as little as 30 minutes.

Melatonin, the Sleep Hormone

Melatonin is a sleep aid that works a little differently. Rather than simply sedating you – like some of the strongest sleeping pills out there – melatonin works with your natural circadian rhythm to help support your existing sleep routine.

Really, melatonin is a hormone produced by your brain’s pineal gland that gets released every evening before you go to sleep. It’s known as the “sleep hormone” because its role is to help you feel drowsy and ready for bed. It works in response to changes in the light. So, when evening comes and darkness falls, melatonin will naturally be released to get you feeling sleepy.

However, for people that don’t find it easy to sleep, artificial melatonin support can be really useful. Why? Because it supports those natural feelings of drowsiness to counteract your sleep problems.

Sounds good. But how exactly does melatonin work? And, crucially, how long does melatonin take to work?

How Does Melatonin Work?

Melatonin works to help you sleep by making you drowsy and lowering your body temperature. It is understood to do this by making you relax by binding to particular receptors on cells. For example, there’s evidence that melatonin reduces nerve activity by binding to receptors in the brain.

Melatonin supplements or tablets work in the same way as natural melatonin. They bind to the same receptors and induce the same chemical effect. As one study showed, melatonin tablets help to reduce the amount of time it takes to fall asleep by an average of 7 minutes.

The medicine is usually prescribed for short-term sleep problems and insomnia in people over the age of 55. However, it’s regularly prescribed off-label to help treat sleep disorders and sleep disruptions in the general population.

Note. In the UK, melatonin is only available on prescription. While it’s classed as a dietary supplement in the US, it is not available over the counter in the UK. So, if you need it, you’ll have to speak to a GP, or a pharmacist such as Manual.

If you’re in the US, you can find local information on melatonin from the Food and Drug Administration (FDA).

How Long Does Melatonin Take to Work?

Typically, medical advice states that melatonin takes about 1 to 2 hours to work. As a result, you should take melatonin about 1 to 2 hours before you intend to go to bed.

In some cases, melatonin has been known to work more quickly – in as little as half an hour. However, you shouldn’t count on that.

Note that if you’ve taken a dose of melatonin and you’re not yet feeling sleepy, do not take another dose. It can increase the likelihood of side effects.

Typically, you will only be prescribed melatonin for a maximum of 1 to 4 weeks. Taking it for longer periods can reduce its effectiveness.  

How Long Will Melatonin Make You Sleep?

With melatonin, you can’t really say that taking the medicine will guarantee you will be able to sleep for a particular length of time. It is not a conventional sleeping pill.

Rather, melatonin will help to regulate your own internal clock – and so, it will help you maintain your normal sleep schedule. That means that you’ll wake up the next day as normal, but this time after a good night of sleep.

Tips to Make Melatonin Work at Its Best

Melatonin is an incredibly powerful sleep aid. But it won’t be able to do everything all by itself. To boost the chances of optimal effects, it’s important you take melatonin as recommended. Here are some good tips to follow:

  • Follow the dosage. A larger amount of melatonin does not make it more effective. You will typically be prescribed a 2mg dose of melatonin to take a day. Don’t take more than that without explicit healthcare advice.
  • Take after food. Swallow the tablet whole, without chewing or crushing it.
  • Avoid alcohol and cigarettes. These are known to reduce the effectiveness of melatonin.
  • Improve your sleep hygiene. Stress and blue light are known to reduce natural melatonin production. Turning off any devices and creating a comfortable, cool, and calm environment for sleep will help.
  • Exercise. Regular exercise is known to promote better sleep. If you’re struggling with jetlag, it can help you get back on your sleep pattern.
  • Watch out for side effects. All medicines have side effects and melatonin is no exception. However, they are usually mild. You may feel daytime sleepiness, irritability, or dizziness. Do not drive after taking melatonin.
  • Tell your pharmacist if you are on other medication. Drugs for high blood pressure and some antidepressants can interact with melatonin. Tell your pharmacist if you are taking these – or if you are breastfeeding.
  • Support melatonin with natural supplements. We recommend taking melatonin with Good Nights, our natural sleep aid.

Key Takeaways

Melatonin is a natural hormone that helps you sleep. But it’s often also taken by shift workers, international travellers, and people with short-term sleep problems to help tackle their insomnia.

How long does melatonin take to work? About 1 to 2 hours. But always stick to the recommended dose.


Does Melatonin Work Immediately?

Melatonin gets to work immediately to help you sleep. You’ll see the results within 1 to 2 hours. Some people feel sleepy even sooner.

Are There Any Negative Side Effects of Taking Melatonin?

The side effects of melatonin are usually mild. They can include dizziness, sleepiness during the day after, and mild irritability. In some cases, you may have nightmares or have a slight stomach ache.

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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