Melatonin: What is it and what has it got to do with sleep?

Sleep is essential for good health. The fundamental biological processes that happen during sleep allow our bodies to function correctly; our brains store new information, cells are repaired and reorganised, and molecules, hormones, and proteins are released, energising us and helping us to get the most out of our time asleep.

Yet, there are other biological processes that occur while we’re still awake that play a fundamental role in how well we sleep, and the cycles of being asleep and awake. One of these processes has to do with a hormone called melatonin.

What is melatonin?

Often referred to as the sleep hormone, melatonin helps to control our sleep-wake cycles, helping to regulate our circadian rhythm. It is produced in the pineal gland in our brains and released into the bloodstream. 

Melatonin production is increased or decreased according to external factors, like light and the time of day. When we’re surrounded by darkness, our bodies produce more melatonin, promoting sleep. The body continues to produce melatonin as we sleep. Exposure to light causes melatonin production to stop. 

Beyond just making us feel tired each night, melatonin contributes to longer term sleep health. Waking up and going to sleep at the same time each day over a period of time is an effective way to improve your ability to fall and stay asleep. And since the body continues to produce melatonin as you sleep, it also promotes sleep consolidation. The role melatonin plays in synchronising the sleep-wake cycle with the cycle of day and night supports this regular ongoing sleep routine.

Melatonin created naturally within the body is known as endogenous melatonin, but it can also be produced externally and taken as a supplement.

Can melatonin supplements improve your sleep?

Research has shown that in some cases, melatonin supplements can help to address irregular sleep patterns or sleep difficulties. However, they aren’t for everyone—or indeed every situation. 

In the UK, melatonin supplements are available by prescription only. Your doctor can help you determine whether melatonin is right for you.

When to ask your doctor about melatonin supplements

Speaking to your doctor about the potential benefits and side effects to melatonin will ensure you make an informed and considered decision about whether melatonin is right for you, and in what dosage.

Some situations or sleeping problems for which melatonin supplements may have potential benefits include:

• “Night owls”, people who tend to be more active or wakeful at night.

• People with a circadian rhythm disorder in which their sleep schedule is not synchronised with day and night.

• Jet lag, a condition that can occur when a person travels across different time zones. The rapid shift in time zones causes a misalignment of the person’s sleep schedule with the local time zone.

• Shift work. People who work night shifts often struggle to get enough sleep during the day, when they’re not working. Often working a mix of daytime and night shifts, shift workers often struggle with a misaligned internal clock.

Some of the research into the benefits of melatonin supplements has been inconclusive, particularly when it comes to its potential in treating insomnia in adults who are otherwise healthy and not suffering from jet lag or a circadian rhythm disorder. If you suffer from symptoms of insomnia, it’s best to consult your doctor or a sleep coach for an in-depth discussion about the benefits and risks, to determine whether additional melatonin could help improve your sleep, and to look into other ways to treat your symptoms.

Improving your sleep without melatonin supplements

There are many other ways to address symptoms of insomnia or sleep difficulties that don’t involve supplements or medication. By building new habits around your lifestyle and sleep routine, such as exercise, diet, and sleep hygiene, you may find that you’re able to manage many symptoms yourself. 

Reducing consumption of alcohol and caffeine, especially late in the day can help to improve sleep, as can increasing your intake of magnesium-rich food, such as nuts and leafy greens. Magnesium plays an important role in sleep regulation, helping your body relax and reducing stress.

Cognitive behavioural therapy for insomnia (CBTI) is an evidence-based approach to managing the symptoms of insomnia that explores the connection between how people think, feel, and behave when it comes to sleep.

When considering the role melatonin and supplements might play in the way you manage your sleep, remember that your exposure to light affects your body’s own melatonin production. You can help regulate melatonin production simply by introducing some new practices, such as making sure you get plenty of natural light during the day, reducing screen time in the evening, and choosing some warm, gentle lighting options for your bedroom.