How melatonin tablets work

Melatonin is a natural hormone produced by the pineal gland in the brain. It is an important regulator of your sleep-wake cycle or circadian rhythm. Because of this, melatonin tablets are prescribed for sleep issues such as insomnia and jet lag.

In this guide, we explore how melatonin works for insomnia, whether it really helps you fall asleep, and what to do if it isn’t working for you.

Melatonin is a hormone produced by the pineal gland in the brain that is critical for helping your body prepare for sleep. Melatonin levels peak at night when it is dark, signalling to your body that it is time to sleep, and return to normal levels during the day when it is light, and you need to be awake.

Melatonin tablets work by supplementing the body’s natural production of melatonin, which is released by the pineal gland in response to fading light and darkness in the evening to signal that it is time to sleep. Melatonin supplements bind to the melatonin receptors in the brain to promote a state of “quiet wakefulness”, making it easier to fall asleep.

Melatonin tablets differ from other sleeping aids with a sedative effect, which can cause drowsiness and often override the body’s normal sleep-wake cycle to induce sleep. Instead, melatonin sends messages to the brain to signal that it is time to wind down and prepare for bed rather than forcing you to sleep.

Although melatonin helps to prepare your body for sleep, it does not have a sedating effect, like other sleeping pills. One study found that 2mg of melatonin for 3 weeks, followed by a 2-week withdrawal period, improved sleep quality and morning alertness in 47% of people, compared with 27% given a placebo.

Another study found that melatonin reduced the time to fall asleep by 24 minutes, compared with 13 minutes with a placebo. Overall, melatonin does not force your body to sleep, but it can improve the time it takes to fall asleep, your quality of sleep, and reduce the severity of sleep problems by promoting a more natural sleep state.

Melatonin vs Quviviq

Melatonin and Quviviq are both prescription-only medications for insomnia. Melatonin supplements your body’s natural melatonin production to help regulate your sleep cycle, but it is usually prescribed for short-term treatment, often 13 weeks or less.

Quviviq is a long-term treatment for chronic insomnia that works by blocking wakefulness chemicals by binding to orexin receptors.

Melatonin standard-release tablets usually take around 1 to 2 hours to work, but they can be effective in as little as 30 minutes in some people. You may need to take it consistently for a few nights to feel the full benefit of melatonin because it is not an instant sedative.

To fully reset your sleep-wake cycle, taking melatonin consistently for 1 to 2 weeks may be needed. If you have been experiencing persistent sleep issues, you should notice a difference by this time.

In most cases, melatonin will have cleared the body within 4 to 10 hours, which is why some people may still wake up during the night when taking it.

Melatonin has a short half-life of 45 to 65 minutes for standard-release tablets and 3.5 to 4 hours for prolonged-release types. Half-life describes the amount of time it takes for the active ingredient to be reduced by half in the body.

If you find you are still waking during the night, you may need prolonged-release melatonin tablets, which release melatonin steadily throughout the night and may cause morning grogginess. Standard-release melatonin pills work quickly, but their effects wear off faster.

Melatonin may not be effective for everyone. It works by regulating your internal body clock to encourage sleep rather than by having a sedating effect that forces you to sleep. There are several reasons why it may not work for you, including taking it at the wrong time, inconsistent use, or taking the wrong dose.

Wrong timing

Melatonin can take 30 minutes to 2 hours to take effect, so it is best taken 1 to 2 hours before bed. Taking it just before bed is usually too late because it does not work by knocking you out.

Inconsistent use

Not taking melatonin consistently can affect how well it works for you. If you have been told to take it every night, set an alarm to remind you so that you do not miss doses.

Too much light before bed

Blue light from screens, such as TVs, mobile phones, and laptops, suppresses your body’s natural melatonin production and can make supplements less effective because the light signals to your brain that it's daytime.

You should avoid screens for 1 to 2 hours before bed to encourage melatonin production and help the tablets work. A good way to do this is to avoid screens as soon as you take the melatonin tablet.

Wrong dose

The recommended melatonin dose for insomnia is 2mg once daily for up to 13 weeks. If you think you may be on the wrong dose, speak to your doctor for a medication review.

Underlying health issues

Melatonin does not treat the underlying causes of sleep problems and insomnia, such as stress, anxiety, or sleep apnoea. Making healthier lifestyle choices, practising mindfulness, getting regular exercise, and seeking appropriate treatment can help address the causes of insomnia and improve your sleep.

What should I do if melatonin doesn’t work?

If melatonin isn’t working for you, there are several things you can try, like:

• avoiding caffeine and alcohol, which are stimulants that can stop melatonin from working
• improving your sleep hygiene by going to bed at the same time each night and waking at the same time every morning
• making sure that your room is cool, dark, and clean
• reducing screen use and dim the lights 1 to 2 hours before bed to signal to your brain that it is time to prepare for sleep

If your sleep problems continue, consider insomnia alternatives, such as Quviviq or see a sleep specialist.

Does melatonin work the first night?

Yes, melatonin can work on the first night that you take it. It is best taken 1 to 2 hours before going to bed, but unlike other sleeping pills, melatonin does not have a sedative effect, so it may not work instantly for everyone. It usually works best when it is taken consistently over several days.

Can melatonin stop working over time?

Yes, melatonin can stop working for some people, especially if it is taken long-term. One study found that loss of response to melatonin can be due to slow melatonin metabolism. This may happen because the liver is less able to break down certain substances, including medications.

Does melatonin work for jet lag?

Yes, melatonin is an effective treatment for reducing jet lag symptoms. It helps to reset your sleep-wake cycle, especially when travelling across different time zones, reduces daytime fatigue, and improves your sleep quality. You can request melatonin for jet lag using our Jet Lag Service.