Can You Take Magnesium With Melatonin?

Quick answer

We found no source saying magnesium and melatonin change how each other works or is absorbed. Melatonin sleep trials used 0.1 to 5 mg, the one magnesium bisglycinate sleep trial used 250 mg of magnesium, and the upper limit for magnesium from supplements is 350 mg a day.^1,2,3

Key facts

Sleep trials of melatonin used 0.1 to 5 mg, almost always taken in the evening.¹
The one sleep trial of magnesium bisglycinate gave 250 mg of magnesium a day, 30 to 60 minutes before bed, for four weeks.²
The upper limit for magnesium from supplements and medicines is 350 mg a day for adults, and it does not count magnesium in food.^3,4
One trial gave 5 mg of melatonin, 225 mg of magnesium and 11.25 mg of zinc together to 43 care home residents, so it cannot show what each did.⁵
Magnesium is absorbed in the gut and stored mostly in bone and soft tissue, while only about 15% of a swallowed melatonin dose reaches the blood.^4,6

Two different kinds of supplement

Melatonin is a hormone your brain produces in response to darkness. It helps with the timing of your 24-hour internal clock and with sleep.⁷

Magnesium is a helper for more than 300 enzyme systems in the body.⁴

One is a signal that tells the body clock night has arrived. The other is a nutrient the body needs whether or not anyone is thinking about sleep. That is why the usual worry about stacking two similar products does not map neatly onto this pair: they are not two versions of the same thing, and neither is a substitute for the other.

What each has been studied for in sleep

Helps you fall asleep a little sooner on nights of occasional sleeplessness*^1,8,9

Moderate evidence

Pooled placebo-controlled trials show melatonin shortens the time it takes to fall asleep by about 4 minutes (17 studies, 284 people) to 7 minutes (19 studies, 1,683 people, doses of 0.1 to 5 mg). The effect is consistent but small, most trials were short, many enrolled people with diagnosed sleep problems, and the largest 2 mg trials used a slow-release tablet.

Amount studied: 0.1 to 5 mg, almost always taken in the evening

May modestly improve self-rated sleep in adults who sleep poorly*^2,10

Early evidence

One randomized, placebo-controlled trial tested this form: 155 adults who slept poorly took magnesium bisglycinate (250 mg of magnesium a day) or placebo for four weeks. Scores on a sleep-problem questionnaire fell a little more with magnesium (3.9 points against 2.3), a small effect, and other measures did not differ. It is a single short trial that relied on self-report. Older trials used other forms at higher doses in older adults and were rated low quality.

Amount studied: 250 mg a day as bisglycinate, 30 to 60 minutes before bed, for four weeks

Both effects are small, and they were measured differently. The melatonin trials timed how long it took to fall asleep, while the magnesium trial used a sleep-problem questionnaire and found no difference on its other measures. The two results are not the same size or the same kind.^1,2

Amounts and timing in the studies

What the sleep studies used^1,2,3,7,11
	Melatonin	Magnesium
Amount	0.1 to 5 mg a day in adult trials	250 mg of magnesium as bisglycinate, in the one trial of this form
Timing	Evening, often 30 minutes before bed; one analysis suggested about 3 hours before	Two capsules 30 to 60 minutes before bed
Length	Mostly short trials; longer trials and higher doses showed larger effects	Four weeks
Upper limit	None set	350 mg a day from supplements and medicines for adults

The one trial that gave them together

A 2011 trial in an Italian care home is the closest thing to evidence on the pair. Forty-three residents, with an average age of about 78, took a food supplement of 5 mg of melatonin, 225 mg of magnesium and 11.25 mg of zinc, mixed into pear pulp, 1 hour before bed for 8 weeks. Their sleep questionnaire scores came out better than with placebo.⁵

Three things limit what that tells you. The supplement also held zinc, so the result cannot be credited to melatonin and magnesium alone. The melatonin amount was at the top of the range other trials used. And the people were older adults living in care, who may respond differently from a younger adult at home.^1,5

Does one change how the other is absorbed or cleared?

The sources do not say so. A review of melatonin's pharmacokinetics names age, caffeine, smoking, birth control pills, food and one antidepressant as factors that change how the body handles a dose, and magnesium is not among those it names. For magnesium, the factors listed in the sources are the amount taken, the person's magnesium status and what else is in the meal.^6,12

Only about 15 percent of a swallowed dose of melatonin reaches the bloodstream on average, with a range of 9 to 33 percent across studies.⁶

What else is in a meal changes how much magnesium is taken up. Phytate, oxalate, some kinds of fiber and high doses of other minerals lower uptake; protein, medium-chain fats and some carbohydrates, such as inulin and resistant starch, raise it.¹²

Who should ask first

The upper limit for magnesium from supplements and medicines is 350 mg a day for adults. It does not count magnesium in food and drinks.^3,4

Melatonin may stay active longer in older people than in younger people and cause daytime drowsiness.⁷

Ask your pharmacist or doctor first

NCCIH says people taking blood thinner medicines need to be under medical supervision when taking melatonin. A Cochrane review noted case reports suggesting that people taking warfarin may come to harm from melatonin, and called for the possible interaction to be studied.^7,13

Reported in studies

Magnesium: ask first if you take an antibiotic, a bisphosphonate, a diuretic or a medicine for acid reflux, or if you take gabapentin or levothyroxine, or if you have kidney disease or reduced kidney function.^3,4
Melatonin: ask first if you are pregnant or breastfeeding, have epilepsy or take medicine for seizures, take sleeping pills or other medicines that cause drowsiness, or take birth control pills or other hormone medicines.^7,14,15
Either: ask first if sleep trouble has lasted more than a few weeks.¹⁶

What is in our products

What’s in ours

Magnesium Glycinate: Magnesium, 275 mg per serving, from the label
Men's Multi: Magnesium, 50 mg per serving, from the label
Creatine + Electrolytes: Magnesium, 60 mg per serving, from the label

What’s in ours

Sleep: Melatonin, 2 mg per serving, from the label

Questions people ask

Do I need to space magnesium and melatonin apart?

No source we read sets a gap between them. Melatonin trials mostly gave it in the evening, and the magnesium bisglycinate trial gave capsules 30 to 60 minutes before bed. Spacing rules do exist between magnesium and some medicines, so ask your pharmacist if you take one.^1,2,4

Can I take both every night?

NCCIH says short-term melatonin use appears safe for most adults and that long-term information is lacking. The magnesium bisglycinate trial ran four weeks, and the combined care home trial ran eight. We found nothing longer for the pair.^2,5,7

Is there a magnesium limit to keep in mind?

Yes. The upper limit for magnesium from supplements and medicines is 350 mg a day for adults. Melatonin has no upper limit set, and NCCIH says information on higher doses is limited.^3,7

Does the type of magnesium matter when pairing it with melatonin?

The melatonin sources do not mention magnesium forms. For magnesium, a 2017 review found the amount taken and a person's status matter more for absorption than the type of salt, and the one sleep trial used bisglycinate.^2,12

See what we make

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See the Full Measure line Creatine + Electrolytes Magnesium Glycinate Men's Multi

Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.