When should you try magnesium for sleep?

Los Angeles-based, board-certified holistic nutritionist Katie Bressack, INHC, AADP, revealed an important distinction with me: melatonin can be effective when sleep trouble is temporary or circumstantial, like when you’re jet-lagged or an extra-long weekend snooze throws off your sleep schedule. 

But when a lack of sleep continues for an extended period, Bressack explains: “Magnesium works better for sleep consistently.”

She added that this is particularly true during periods of hormonal change. Indeed, during this phase, I spoke with my board-certified medical doctor, who ran diagnostic tests and confirmed that I’d experienced some significant fluctuations in my hormone levels.

Similarly, if you’re considering taking magnesium for sleep (or changing your nutrition or sleep regimen), it’s important to talk to your licensed healthcare professional first. Registered dietitian Sally Twellman, RDN, says that, in particular, people taking diuretics, antibiotics, or heart medicine could experience an interference with medication absorption. Those with chronic conditions like diabetes, heart disease, or kidney disease should also avoid taking a magnesium supplement without medical supervision.

More than half of Americans today may be at risk for a magnesium deficiency, according to 2025 research published in Nutrients. This may, in part, help explain why the National Sleep Foundation reports that up to six in 10 Americans say they have trouble sleeping. 

Here’s the link: magnesium helps regulate and optimize the release of hormones involved in sleep, including serotonin and melatonin. The mineral is also known to help: 

Together, these magnesium benefits can contribute to a gentler wind-down and a more restful night.

How long does it take for magnesium to help you sleep?

Even though magnesium might not work, well, overnight, I did notice that the effects didn’t take long to set in. Bressack recommends taking magnesium about an hour before bed, but I simply took it in the morning with my multivitamin and coffee, letting it get to work in my system at a time of day I already carve out for my supplements. (Drinking water too close to bedtime can also keep me up at night!)

Bressack says she’s witnessed many of her clients experience a restful effect of magnesium after “just a few days—not too long.”

Which form of magnesium is best for sleep?

Some healthcare professionals suggest that magnesium glycinate is the ideal form of the supplement. That’s because glycine, an amino acid, helps your body better absorb magnesium.

Bressack also says you can boost your magnesium intake through food. She recommends dark leafy greens and avocados, while the National Institutes of Health lists black beans, chia seeds, potatoes (skin-on), and almonds as a few of the highest-magnesium foods.

After consulting with Bressack and my doctor, I took an extra-strength magnesium supplement from Nature Made. The 400-milligram dose is slightly higher than the recommended daily allowance (RDA) for adults: 310 to 320 milligrams for women and 400 to 420 milligrams for men. Under the supervision of two healthcare professionals, this dosage worked well for me.