← The FormularyLong gameMagnesium glycinate
Also known as Magnesium bisglycinateThe mineral most diets are short of, in the form that behaves.
Magnesium is the rare supplement where the marketing undersells the evidence rather than the other way round. It has real approved claims, most diets genuinely fall short, and it costs very little. The form matters more than people expect: oxide is cheap and poorly absorbed and sends a lot of men straight to the bathroom, glycinate is gentler and better tolerated. The one thing to be sceptical about is the sleep story. Glycinate gets sold as the sleep magnesium and the evidence there is much thinner than the evidence for everything else it does.
Magnesium bound to the amino acid glycine, which is what makes this form gentle on the stomach compared with the cheap oxide version.
It is a cofactor in several hundred enzyme reactions, including the ones that release energy from food and the ones that let muscle fibres relax after contracting. Being short of it shows up as fatigue and twitchiness long before anything dramatic happens.
Contributes to normal muscle function, to normal functioning of the nervous system, to the reduction of tiredness and fatigue, and to normal protein synthesis.
Most people, honestly. Anyone training hard, anyone eating few leafy greens, nuts or whole grains. Not for anyone with kidney disease without a doctor.
Around 275 mg elemental daily, in one go or split. Loose stools mean take less. Keep two hours clear of tetracycline or quinolone antibiotics and bisphosphonates.
Less of the low-grade tiredness if you were short, over weeks. Nothing dramatic on day one. If you were not short you may notice nothing at all, which is how minerals work.
Grade A for the authorised claims at 15% NRV and above. The sleep evidence is weaker and separate; do not read the grade as covering it.
Read the labelAbove 250 mg supplemental, loose stools are common. Avoid with kidney disease. Separate from some antibiotics.
Evidence grades describe how well an ingredient is studied — A well-supported, C emerging — not a promise of results. Educational, not medical advice. Doses are typical ranges; follow the label on the product.