Melatonin or magnesium: Which helps sleep better?

Melatonin and magnesium are often used for better sleep, but they work differently and are not suitable for everyone.

Many people experience, even occasionally, difficulty sleeping. Stress, the pressure of everyday life, irregular habits, and even someone's natural predisposition to go to bed late or wake up very early can prevent an adequate and quality night's sleep.

The problem is not negligible. Sleep is a basic requirement for physical and mental health , while chronic lack of it has been linked to an increased risk of obesity, type 2 diabetes, hypertension and cardiovascular disease.

When sleep difficulties persist, many people turn to over-the-counter supplements, most notably melatonin and magnesium. While both may be helpful in some cases, they do not work as sleeping pills and cannot treat chronic insomnia.

Chronic insomnia is considered difficulty initiating or maintaining sleep at least three times a week, for a period of three months or more.

Before taking any supplement, it is important to consult a doctor, especially if you are taking medication or have a chronic condition. You should also pay attention to the quality of the products, as dietary supplements are not regulated in the same way as prescription drugs.

Melatonin: When can it help?
Melatonin appears to be most useful when the main problem is difficulty falling asleep at the desired time. It is a hormone naturally produced by the brain and helps regulate the sleep-wake cycle. When it gets dark, its levels increase and enhance the feeling of sleepiness, while in the morning they subside, making it easier to wake up.

For this reason, melatonin supplements can help people whose biological clocks are out of sync with their daily schedule. They may be useful for those who have a strong tendency to sleep very late, for night shift workers, or for travelers who experience jet lag.

According to Anita Selgikar , a professor of neurology at the University of Michigan Medical School and past president of the American Academy of Sleep Medicine, melatonin can help synchronize the internal biological clock with the light and dark cycle.

A review of 26 randomized trials, published in 2024, found that melatonin can reduce the time it takes to fall asleep and slightly increase total sleep time. The most notable effects were seen with a daily dose of 4 mg, taken about three hours before your desired bedtime.

Experts, however, usually recommend lower doses, in the range of 1 to 3 mg, for a limited period of time. Michael Gradner , director of the Sleep and Health Research Program at the University of Arizona, points out that in most cases, it is not advisable to exceed 5 mg , as there is insufficient evidence that higher doses offer a better result.

The exact time of day is important. It is usually recommended that melatonin be taken two to three hours before your desired bedtime. It also helps to keep a consistent schedule, get plenty of light in the morning, and limit lighting and screens just before bedtime.

If melatonin is taken at a time when the body has already begun to produce a sufficient amount, the additional benefit may be small. Therefore, when no improvement is observed, it is not advisable to arbitrarily increase the dose , but to seek medical advice.

Particular caution is required in children. Administration should only be done with the consent of a pediatrician and in very low doses. Peter Cohen , a pathologist at Cambridge Health Alliance and associate professor at Harvard Medical School, warns that there have been recorded cases of accidental overdose that even led to hospitalization.

Melatonin may also be more useful in older people, as its natural production gradually declines over the years. In addition, certain medications, such as beta-blockers, can further reduce its nocturnal secretion.

This, however, does not mean that it is harmless in every case. Melatonin can interact with anticoagulants, antiepileptics and immunosuppressive drugs . For this reason, its use should be done with caution and always with the knowledge of the treating physician.

Magnesium: Milder help and less data
Unlike melatonin, magnesium has not been studied as extensively as a sleep aid. It is, however, an essential mineral that participates in many functions in the body, including normal nerve and muscle function.

Normally, magnesium is best obtained through diet. Rich sources include green leafy vegetables, legumes, nuts, seeds, and whole grains.

Its possible relationship with sleep is explained by two main mechanisms. On the one hand, magnesium indirectly participates in the melatonin production process. On the other hand, it contributes to the normal functioning of muscles and may facilitate their relaxation, although scientific evidence for the treatment of muscle cramps remains conflicting.

Studies to date are limited and usually show little benefit. In a small trial published in 2025, people who took 250 mg of magnesium bisglycinate daily for a month experienced improved sleep compared to those who took a placebo.

Michael Gradner believes that magnesium can help with mild or transient sleep difficulties, especially when muscle tension is present. As he points out, its effects are usually not as strong as many believe, but that does not mean they are non-existent.

Those who choose to try it usually prefer magnesium glycinate or bisglycinate, at a dose of about 250 mg at night. Anita Selgikar clarifies, however, that this recommendation is largely based on empirical observations, as scientific data remains limited.

In contrast, magnesium citrate is not considered a suitable choice for sleep , because it is often used as a laxative and can cause gastrointestinal discomfort during the night.

The most common side effects of magnesium are diarrhea, abdominal cramps, and vomiting. It can also interact with certain antibiotics, antihypertensives, and osteoporosis medications, and may worsen conditions such as myasthenia gravis (a neuromuscular disorder).

Which supplement is ultimately more suitable?
Overall, melatonin seems to be most appropriate when the problem is related to the synchronization of the biological clock and difficulty initiating sleep . It may also be useful in cases of jet lag, shift work, or reduced natural production of the hormone due to age.

Magnesium, on the other hand, may offer limited help with mild, transient sleep disorders or muscle tension. However, the available scientific evidence is clearly less and does not justify expectations of spectacular results.

In any case, neither supplement is a substitute for proper diagnosis and appropriate treatment . When insomnia persists for weeks, affects daily functioning, or is accompanied by severe fatigue, loud snoring, breathing interruptions, or other symptoms, an evaluation by a doctor or sleep specialist is required.