How Magnesium supports nerve and muscle function

Discover how magnesium supports nerve communication, muscle contraction and relaxation, energy production and daily movement. Plus, food sources and supplement tips.

Around 31% of people did not meet their magnesium requirements from food and drinks in 2023, according to the Australian Bureau of Statistics. Magnesium is one of the most active minerals in the body, working quietly across hundreds of everyday processes. Two of its best understood roles sit in the nervous system and the muscles, which is why magnesium comes up so often in conversations about movement, recovery and relaxation.

This article explains what magnesium does inside the body, how it supports nerve communication and muscle function, what can lower your levels, where to find it in food, and what to consider if you are thinking about a supplement.

What magnesium does inside the body

Magnesium is an essential mineral, meaning the body cannot make it and needs to obtain it from food, drinks or supplements. It is among the most abundant minerals in the body, with most of it stored in the bones and the rest held in muscle and soft tissue.

The NIH Office of Dietary Supplements describes magnesium as a cofactor in more than 300 enzyme systems that regulate reactions throughout the body, including protein synthesis and muscle and nerve function. A review in Physiological Reviews, notes that magnesium is the second most abundant cation inside our cells and is closely tied to energy metabolism.

Much of this involves ATP, the molecule cells use for energy. Magnesium binds ATP to form MgATP, the usable form that powers most energy-dependent reactions. Nerve signalling and muscle movement both draw on this supply, which is part of why magnesium is linked so closely to how the body moves and functions day to day.

Magnesium and nerve communication

Nerves talk to each other through tiny electrical signals, created by minerals moving in and out of nerve cells. The NIH Office of Dietary Supplements notes that magnesium plays a role in the active transport of calcium and potassium ions across cell membranes, a process that underpins nerve impulse conduction. With too little magnesium, this signalling system does not run as smoothly.

Magnesium also helps keep nerve signalling measured rather than overexcited, acting as a kind of gatekeeper at certain receptors in the nervous system. A 2025 structural study in Neuron mapped how magnesium sits inside the NMDA receptor, a channel involved in nerve signalling, and is released only when a strong enough signal arrives. This gatekeeping role helps the nervous system tell a meaningful signal apart from background noise.

The Neuron study also helps explain why magnesium is linked to a steady nervous system: by sitting at these receptors until a strong signal arrives, it helps keep nerve activity balanced rather than over-excited, working alongside minerals such as potassium, sodium and calcium.

Muscle contraction and relaxation explained

Muscle movement is a cycle of contraction and relaxation, and magnesium has a hand in both.

When a muscle contracts, calcium moves into the muscle cell and binds to regulatory proteins, allowing the muscle fibres to shorten and generate force. A review in Magnesium Research describes how magnesium works together with ATP in the cross-bridge process that drives this contraction.

Relaxation depends on magnesium too. The same Magnesium Research review notes that the relaxation phase relies on calcium being pumped back into storage within the muscle fibre, a step that also requires magnesium and ATP. This balance between contraction and relaxation is the mechanism behind one of magnesium's recognised roles: supporting muscle function and muscle relaxation.

Why magnesium matters for movement

Movement depends on the nervous system and the muscles working together. A nerve signal travels from the brain to a muscle, the muscle contracts, then relaxes, ready for the next movement. Magnesium contributes at several points in this sequence: the nerve signalling that carries the instruction, the energy supply that powers the muscle, and the calcium balance that lets the muscle relax afterwards.

This combined role is why magnesium is often discussed in the context of everyday movement, physical activity and recovery after exercise. The Magnesium Research review describes an adequate magnesium status as essential for normal skeletal muscle function across all ages. Its contribution is foundational, supporting the systems that make smooth, coordinated movement possible rather than acting as a quick fix.

Magnesium, electrolytes and everyday energy

Magnesium is also one of the body's electrolytes, the charged minerals that include sodium, potassium and calcium. Electrolytes help regulate fluid balance and support nerve and muscle activity, and magnesium sits within this group while carrying a wider role in energy metabolism.

That wider role comes back to ATP. As the Physiological Reviews review describes, magnesium is part of the cellular machinery that produces and uses energy through MgATP, rather than a direct source of energy itself. This is an important distinction: magnesium does not provide an instant lift the way caffeine or sugar might. It supports the underlying processes that turn food into usable energy and keep muscles and nerves working, across both rest and activity.

What can lower your magnesium levels

Several everyday factors can nudge magnesium intake or status lower. Diet is the most common one. The NIH Office of Dietary Supplements notes that refining grains removes much of their magnesium, so a diet heavy in refined and processed foods tends to supply less than one built around wholefoods.

Other factors can play a role too. The same fact sheet lists older adults, people with certain digestive conditions, and those who regularly drink large amounts of alcohol among the groups more likely to have low magnesium, partly because absorption can decrease and losses through the body can increase. Some medications can also affect magnesium levels, which is worth raising with a pharmacist or GP if it applies to you.

Signs your body may need more magnesium

Most people can meet their magnesium needs through food, though intake gaps still occur. Early signs of low magnesium intake can be vague and easy to miss, such as reduced appetite, tiredness or general weakness. These signs overlap with many other everyday causes and are not a diagnosis on their own. If you are concerned about your magnesium intake or notice persistent symptoms, a conversation with your GP is a sensible next step.

Food sources of magnesium

Food is the foundation for healthy magnesium levels. Healthdirect notes that leafy greens, legumes, nuts, seeds and wholegrains are among the richest sources, and that most people get the magnesium they need from a varied diet.

Practical everyday options include:

• Leafy green vegetables such as spinach and silverbeet
• Legumes such as chickpeas, lentils and black beans
• Nuts and seeds such as almonds, cashews and pumpkin seeds
• Wholegrains such as brown rice, oats and wholegrain bread

Foods high in dietary fibre tends to be good sources as well. For adults, the Nutrient Reference Values set the recommended dietary intake at around 310 to 420 mg per day, varying with age and sex. Spreading foods rich in magnesium across the day is a simple way to work towards that target.

Everyday habits that support nerve and muscle function

Healthy nerve and muscle function is supported by consistent everyday habits rather than any single nutrient or product.

• Eat a varied diet built around the foods listed above, alongside plenty of vegetables, wholegrains and legumes
• Stay physically active, which supports muscle health and general wellbeing
• Prioritise regular, good quality sleep, since rest is when muscles recover
• Manage day to day stress through approaches that suit you, such as time outdoors, breathing practices or social connection
• Stay hydrated and keep alcohol within recommended limits, as both affect mineral balance

Small, repeated choices tend to matter more over weeks and months than any single change on any single day.

Choosing and using a magnesium supplement

When dietary intake is not enough, a supplement can help fill the gap. The form matters, since different types of magnesium vary in how well the body absorbs them and how they sit with digestion.

Comparing common forms

Magnesium supplements broadly fall into organic forms, such as glycinate and citrate, and inorganic forms, such as oxide. A study in BMC Nutrition found that magnesium citrate, an organic form, was more available to the body than magnesium oxide, an inorganic form.

A few practical points help when comparing labels:

• Magnesium glycinate binds magnesium to the amino acid glycine. It is well absorbed and tends to be gentle on the stomach.
• Magnesium citrate is well absorbed and widely used, though it can have a mild laxative effect at higher doses.
• Magnesium oxide carries a high amount of magnesium by weight but is less well absorbed than organic forms.\
• Elemental magnesium is the figure to check on any label, as it tells you how much actual magnesium a dose provides.

Where Blackmores Magnesium Glycinate fits

Blackmores Magnesium Glycinate contains 150 mg of magnesium per film coated tablet, as magnesium glycinate, and is taken with food. It is formulated to support nervous system function and muscle function, and to help relieve muscle cramps and mild muscle spasms when dietary intake is inadequate. It also supports muscle relaxation, a healthy stress response and healthy sleeping patterns.

You can compare forms across the Blackmores magnesium range to find one that suits your routine. A supplement works best alongside a balanced diet, not in place of one. If you take other medications or have a health condition, check with your pharmacist or GP before starting magnesium.

When to speak with a healthcare professional

Magnesium intake gaps can often be addressed through diet, though some situations warrant professional input. Speak with your GP, pharmacist or an accredited practising dietitian if you have ongoing muscle cramps, twitches or weakness, persistent fatigue, or a health condition or medication that may affect magnesium levels. A healthcare professional can check whether magnesium or another factor is involved and suggest an approach suited to you.

Frequently asked questions

What does magnesium do in the body?

Magnesium takes part in a wide range of processes, including energy production, building proteins, and normal muscle and nerve function. This makes it one of the body's most widely used minerals.

How does magnesium support nerve function?

Magnesium helps move calcium and potassium across nerve cell membranes, which supports the electrical signals nerves use to communicate. It also helps keep that signalling balanced rather than overexcited.

How does magnesium help muscle contraction and relaxation?

Calcium triggers a muscle to contract, and magnesium acts as a natural counterbalance that helps it relax again. Both phases rely on magnesium working alongside ATP, the body's usable energy form.

Can magnesium support stress and the nervous system?

Magnesium contributes to normal nervous system function and is recognised as supporting a healthy stress response. It works alongside minerals such as potassium, sodium and calcium to help keep nerve activity steady.

Which form of magnesium is best absorbed?

Organic forms such as glycinate and citrate are generally better absorbed than inorganic forms like oxide. Glycinate is also known for being gentle on digestion.

Should I take a magnesium supplement?

Most people can meet their needs through food. When dietary intake is inadequate, a supplement may help, so speak with your GP or pharmacist if you are unsure.

Key takeaways

Magnesium supports both the nervous system and the muscles, two systems that work together for everyday movement. It helps carry nerve signals, keeps nerve activity balanced, supplies usable energy through MgATP, and works with ATP through contraction and relaxation so muscles can move and recover. Around 31% of Australians did not meet their magnesium requirements from food and drinks in 2023, so a varied diet rich in leafy greens, legumes, nuts, seeds and wholegrains is the first place to focus. When dietary intake is inadequate, a well absorbed form such as magnesium glycinate can help fill the gap alongside healthy daily habits.

Always read the label and follow the directions for use.

Disclaimer: This article provides general information only and is not intended to diagnose, treat, cure, or prevent any disease. The information presented is not a substitute for professional medical advice. If you have concerns about your health, please consult your GP or healthcare provider for a personalised assessment and recommendations. Supplements should not replace a balanced diet.