Magnesium vs. Melatonin: Which Is Better for Sleep?

Ten years ago, bragging about four hours of sleep was a badge of honor. Now? Eight hours is the real power move. In the biohacking bro era of Whoop scores, cold plunges, and longevity podcasts, a full night’s sleep has become the ultimate performance enhancer.

But knowing you need it and actually getting it are two very different things. While maintaining good sleep hygiene in the evening is key to getting consistently adequate shut-eye, many people also turn to the supplement aisle, most often to melatonin or magnesium, for help falling asleep. But does one outperform the other—and should you really take either to begin with?

Melatonin for sleep

Melatonin isn’t just a common sleep aid; it’s a hormone your body naturally produces nightly in anticipation of sleep. Contrary to popular belief, melatonin supplements aren’t exactly sleeping pills at all. Rather, they’re time-setters that reset your circadian rhythm (aka your internal clock) earlier. They work best when timing is the main issue, like when your schedule’s off due to jet lag, shift work, or delayed sleep phase syndrome, says William Lu, MD, sleep medicine physician and medical director at Dreem Health.

Still, according to a 2022 Sleep Foundation Survey, over 27 percent of adults in the U.S. take melatonin regularly, despite its long-term effects requiring further investigation. Per one meta-analysis of 19 studies, supplemental melatonin helped participants fall asleep seven minutes faster, sleep eight minutes longer, and improve overall sleep quality modestly compared to a placebo. So it appears to help—at least marginally.

However, it’s not the right fit for everyone—particularly if you’re dealing with insomnia driven by stress or pain, says Dr. Lu. (More on that soon.) “Timing and dose matter a lot, so taking too much or at the wrong time can actually make sleep feel worse rather than better,” he adds. Research shows that 5 to 6 milligrams or less appears safe, but the bad news is that dosage inaccuracies are far too common. One study of 25 melatonin products found that the actual quantity of melatonin ranged from 74 to 347 percent of what was listed on the label (further cementing the supplement industry as a Wild West of wellness). He also notes that the melatonin hangover—characterized by grogginess and next-day drowsiness—is real for many.

Magnesium for sleep

Compared to melatonin, magnesium is geared more for gentle R&R. “Magnesium supports sleep by helping regulate neurotransmitters involved in relaxation, particularly by binding to GABA receptors in the brain that promote calmness, and by helping lower stress signaling and muscle tension,” says Dr. Lu. Though evidence for using magnesium for insomnia is mixed, he says that effects can be subtle. “The upside is that it can be especially helpful if someone is magnesium-deficient or dealing with muscle cramps, restlessness, or stress-related sleep issues,” he continues.

Magnesium comes in many forms, and some work better than others to promote a good night’s rest. According to Nilong Vyas, MD, MPH, board-certified pediatrician, behavioral sleep coach, and founder of Sleepless in NOLA, the best types of magnesium for sleep include magnesium L-threonate and magnesium glycinate.

“Magnesium L-threonate crosses the blood-brain barrier and supports neurotransmitters involved in melatonin production, while also promoting relaxation and restorative sleep,” says Dr. Vyas. In one randomized, placebo-controlled study of adults with self-assessed sleep issues, those who supplemented with 1 gram of magnesium L-threonate for 21 days experienced significant improvements in scores for deep sleep, REM sleep, and readiness (among other metrics) on their Oura rings, as well as subjective improvements in energy levels, productivity, mood, and mental alertness. Meanwhile, Dr. Vyas says that magnesium glycinate is well-absorbed and can help regulate sleep and promote relaxation. Research shows that it can modestly improve insomnia severity in adults with poor sleep quality, with greatest improvements in those with lower baseline magnesium intake.