Better sleep is only part of the story. Experts explain how magnesium supports your muscles, heart, metabolism and stress response – and why so many people aren’t getting enough
At the start of 2026, searches for magnesium hit a five-year high. The chemical, often associated with improved circadian rhythms and sleep cycles, is the fourth-most abundant mineral in the human body and acts as a key marker in hundreds of your day-to-day biological processes.
From nerve and muscle function to blood pressure and bone development, magnesium contributes to over 300 enzyme systems in the body. So you might want to pay attention to it.
But why the sudden interest? Currently, it’s estimated that around 60% of people are magnesium deficient, and though certain foods — including pumpkin seeds, cashew nuts, spinach, edamame and dark chocolate — can help raise levels, many people opt for supplementation to get more of the mineral through supplementation with magnesium pills or powders.
So, what’s actually happening under the hood once you ingest magnesium? Below, we take a closer look.
Muscle support
However you take it, magnesium acts as a natural calcium ‘blocker’ to your muscles, helping them relax and avoid spasming. At a cellular level, calcium binds itself to troponin C and myosin proteins, generating muscle contractions. When your muscles contract too much, however, they can begin to spasm.
When you take magnesium, it competes to do the same job as calcium, helping you avoid muscle cramps but relaxing your muscle groups. If you ever find your quads, biceps or chest twitching after a particularly heavy workout, magnesium might offer a welcome hand and ease the cramps. DOMS will never feel the same again.
Stress
Stress and magnesium influence one another in a two-way cycle. When you’re under pressure, your body releases stress hormones such as cortisol and adrenaline, which increase the amount of magnesium lost through the kidneys.
Over time, lower magnesium levels may make it harder for your body to cope with stress, reinforcing a cycle in which stress depletes magnesium and magnesium depletion heightens the effects of stress. To dodge the one-two punch of stress, you may want to consider adding magnesium to your supplement stack.
Sleep
This is the area in which magnesium is most commonly associated. For those of us — this writer included — continually grappling with sleep and associated issues, adding magnesium to the daily rotation is a popular method of influencing how we unwind.
By contributing to nervous system regulation, it helps to ease muscle tension and plays a role in the production and function of melatonin, the hormone that governs our sleep–wake cycles. Its benefits tend to be greatest in people who are magnesium deficient or whose sleep is disrupted by stress.
Heart
One less-publicised benefit of magnesium is its connection with cardiovascular function. The chemical helps coordinate the electrical signals that control the heartbeat, supports proper contraction and relaxation of the heart muscle and contributes to healthy blood vessel function.
By promoting blood vessel relaxation and helping regulate vascular tone, magnesium also plays a role in maintaining healthy blood pressure. A decent return on investment, you’ll agree.
Metabolism
By this point, it’s clear that magnesium is somewhat of a workhorse — it’s a cofactor in over 300 enzymatic reactions, many of them central to how the body actually produces and uses energy.
It’s directly involved in glycolysis and helps generate adenosine triphosphate (ATP), the universal energy currency of the brain that keep your cells running. It’s why chronically low intake tends to show up as fatigue, poor exercise recovery and even disrupted blood sugar regulation.
