Is melatonin or magnesium better for your sleep? Experts weigh in

Many people struggle to get a good night’s sleep at some point or another. Anxiety, stress and even your natural tendency to be a night owl or morning lark can interfere with the seven to nine hours of sleep that’s often recommended for folks to get each night.

That can be a problem because sleep is essential to your health. Research shows that poor sleep is associated with increased risks of obesity, Type 2 diabetes, hypertension, cardiovascular disease and more.

If you’re having trouble sleeping, studies show that some over-the-counter supplements such as melatonin and magnesium may help. But there are caveats: neither act as a sedative or can treat sleep disorders such as chronic insomnia – when you have difficulty falling or staying asleep at least three times a week for three months or more.

Keep in mind that you should always talk to your doctor before starting any supplement. Melatonin, for example, is only available in Australia over the counter in low-dose form for those aged 55 and over for short-term insomnia, or adults over 18 as a treatment for jet lag.

So how do you know whether to consider melatonin or magnesium? We spoke to health experts and combed through the research to help answer that question.

Melatonin supplements can help align your body’s internal clock with the sun to help you achieve your desired sleep schedule, says Anita Shelgikar, immediate past president of the American Academy of Sleep Medicine and a professor of neurology at the University of Michigan Medical School.

The supplement can be helpful for people who are naturally inclined to stay up very late or wake up very early, making it difficult to follow a typical work, school or social schedule. People who work night shifts or are experiencing jet lag may also benefit.

The supplement works by mimicking the hormone produced by the pineal gland in the brain that regulates your sleep-wake cycle. Your brain responds to darkness by releasing melatonin to promote sleepiness. Melatonin levels then wane toward the morning, helping you wake up.

A 2024 review of 26 randomised controlled trials found that melatonin reduced the time it took to fall asleep and increased the total time people slept, with the most notable results at 4 milligrams of melatonin per day, taken three hours before the desired bedtime.

Taking low doses – about 1-3 mg daily for a few weeks – is generally considered safe for most healthy adults. But you shouldn’t exceed 5 mg in most cases as there is no reliable evidence that larger doses provide better results, says Michael Grandner, director of the Sleep and Health Research Program at the University of Arizona.

It’s also better to err on the lower end of dosing because supplements tend to be more potent than the listed dosage when fresh from the manufacturer, then degrade to the listed dosing over time, Grandner says. And he prefers a quick-dissolve formulation, when possible. With gummies, it’s hard to know exactly how much melatonin you’re getting or when it will be absorbed, he says.

Generally, you should take melatonin two to three hours before your desired bedtime.