Magnesium is involved in over 300 biochemical processes in the body. Energy production, nerve signalling, muscle function, immune health, sleep regulation. It is, by most measures, one of the most important minerals your body relies on for daily function.

And yet, globally, an estimated 31% of people fail to meet the daily recommended magnesium intake levels. Many more sit in a grey zone of hidden deficiency, low enough to feel the effects, but not low enough to show up on a standard blood test.

The symptoms are easy to miss. Poor sleep, muscle tension, low energy, difficulty unwinding. These are things most people chalk up to a busy life rather than a nutritional gap. Which is exactly why magnesium deficiency so often goes unaddressed.

Why are so many of us low in magnesium?

Modern diets are a significant factor. Increased reliance on processed foods, soil nutrient depletion through intensive farming, and the general move away from wholefoods and vegetables have all contributed to declining magnesium intake over time. Stress and regular exercise can deplete levels further, two things that describe most people's daily lives.

What does magnesium actually do for sleep?

Magnesium plays a direct role in sleep regulation. It supports the release of melatonin, helps maintain a healthy biological clock and promotes deep, restorative sleep.

The research backs this up. A 2024 study found a graded dose-response relationship between magnesium depletion and sleep trouble, meaning the lower the magnesium status, the worse the sleep quality. 

If you are waking unrefreshed, struggling to wind down or lying awake at night, low magnesium could be a factor worth considering.

And what about muscle relaxation and recovery?

Magnesium regulates calcium movements between muscle fibres, supporting relaxation after contraction. Without adequate magnesium, muscles can struggle to fully relax, contributing to tension, cramps and may lead to slower recovery after exercise.

This is relevant not just for athletes but for anyone who carries physical tension through the day or finds it hard to switch off at night. The connection between muscle tension and poor sleep is well established, and magnesium sits at the centre of both.

Does the form of magnesium you take actually matter?

Yes, significantly. Not all magnesium supplements are absorbed equally. Some forms, like magnesium oxide, have lower absorption rates and can cause digestive discomfort.

Magnesium glycinate is magnesium bound to glycine, an amino acid, which allows it to be absorbed more efficiently in the small intestine. It is one of the most bioavailable and well tolerated forms available, making it a sound choice for consistent daily use.

Glycine itself also contributes to the formula. It is an amino acid associated with relaxation and sleep quality, working alongside magnesium to support a calm, restful state. When you see magnesium glycinate on a label, you are getting both the mineral and the amino acid working together.