I Tried Magnesium for Sleep, and It Worked — but I Wasn't Expecting the Side Effects

Every once in a while, there's a buzzy supplement that seems to end up in just about everyone's medicine cabinet. At one point it was collagen. These days, it's magnesium.

Magnesium is an essential mineral that plays a major role in many important bodily processes (like muscle and nerve function, for example), per the National Institutes of Health (NIH).

But it's also been touted recently as a sleep aid, meaning it can improve sleep quality and make it easier to fall asleep. And there is some research to back up these claims, according to the Cleveland Clinic.

I decided to put it to the test. Here's what happened when I took magnesium to help with sleep and whether I'd recommend it based on my experience.

I began taking magnesium as a supplement because I was having trouble falling and staying asleep, mostly due to anxiety, and my psychiatrist recommended it.

Truthfully, the research on just how effective magnesium is for sleep is limited, and results are mixed.

For example, one older December 2012 study in the ‌Journal of Research in Medical Sciences‌ found that when compared to a placebo, magnesium only produced a slight improvement in the ability to fall asleep and sleep quality. (‌Total‌ sleep time was the same for both the placebo and magnesium group.)

But research that looks at magnesium's potential to reduce anxiety symptoms is a bit more promising.

In fact, one May 2017 review in ‌Nutrients‌ suggests magnesium acts on GABA receptors in the brain. (GABA is a neurotransmitter that slows down your central nervous system and produces a calming effect, per the Cleveland Clinic.)

And for someone like me, less anxiety at night means less trouble falling asleep.

"Magnesium can relax and encourage sleep in folks who have insomnia," says James J. McGuirk, MD, a neurologist at Vanderbilt University Medical Center, adding that the nutrient can also be helpful for nocturnal muscle cramps and restless legs syndrome.

"But truthfully, I don't think anyone really knows exactly ‌why‌ it works," Dr. McGuirk adds. More research needs to be done to find the exact reason why magnesium has the relaxing effect it does.

Before I started taking magnesium, I did some research on which type to take. There are many different kinds of magnesium supplements to choose from, including pill, gummy and powder forms. I settled on taking magnesium citrate in powder form.

The Cleveland Clinic specifically recommends taking magnesium citrate or glycinate if you're going to try it for sleep, while avoiding magnesium oxide, because it can act as a stool softener.

Plus, research — including one August 2019 study in ‌Magnesium Research‌ — shows magnesium citrate is generally absorbed well by the body.

Once I found the type of magnesium I wanted to take, I began mixing it into a glass of water and drinking it 30 minutes or so before bedtime. And surprisingly, after a few days, I found myself easily drifting off into slumber instead of anxiously tossing and turning.

There's no doubt it helped me feel more relaxed and fall asleep more easily.

I did notice one interesting (and unwanted) side effect, though: vivid, sometimes frightening dreams. They were so intense that it was stressful to even think about them during the day.

Was the magnesium to blame? Maybe.

But if there's limited evidence on magnesium's effect on sleep, there's ‌none‌ on magnesium's effect on dreams, says Sogol Javaheri, MD, MPH, a sleep medicine specialist and instructor at Harvard Medical School.

We know that we tend to dream during the rapid eye movement (REM) stage of sleep, but we don't know how magnesium affects that stage of sleep yet, Dr. Javaheri adds.

"It's possible that magnesium could cause more vivid dreaming because when we sleep better, we tend to dream more," she says. "There is a biological plausibility, but it's never been shown or proven."

While vivid dreams were my main side effect, there are a few other potential side effects of magnesium for sleep, per UC San Diego Health. They include the following (although keep in mind that these are rare if you're taking magnesium at the daily recommended dose):

• Daytime drowsiness or fatigue
• Muscle weakness
• Nausea
• Vomiting
• Skin flushing
• Diarrhea
• In severe cases, magnesium overdose: This happens when you take more magnesium than directed or prescribed, resulting in heart rhythm abnormalities

I took magnesium for a couple months, but once I suspected it was causing my vivid dreams, I decided to stop taking it every night.

Now, I take it more sparingly, when I am having an especially hard time falling asleep and could use an extra sense of calm.

If you're looking to take magnesium for sleep, the Cleveland Clinic recommends starting with 200 milligrams.

And it's really only safe to take every night if your doctor gives the OK. (Taking it consistently could be putting a bandaid on an underlying sleep disorder that needs treatment — like sleep apnea, per UC San Diego Health.)

Keep in mind, too, that each person's experience with magnesium might be different. Just because it triggered vivid dreams for me doesn't mean it would do the same for you.

"Magnesium is involved in a lot of pathways in the body and it's definitely an essential nutrient," Dr. Javaheri says. "I do believe it could have important effects on sleep — we just need to study it more."