Magnesium
Contributes to normal muscle function, normal functioning of the nervous system, and to the reduction of tiredness and fatigue.
Also known as Mag, Magnesium Glycinate, Magnesium Citrate, Magnesium Threonate, Mag Glycinate, Magnesium L-Threonate, Magnesium Taurate, Magnesium Malate, Magnesium Oxide
Common doses
200-400 mg
Best timing
Evening
Food
With or without food
Interactions
6 known
Magnesium is an essential mineral involved in over 300 enzymatic reactions in the body. It contributes to energy production, protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Despite its importance, magnesium deficiency is one of the most common nutrient insufficiencies in developed countries, affecting an estimated 50% of Americans.
The modern diet is a major factor. Magnesium content in food has declined due to soil depletion and food processing. Stress, alcohol, and certain medications (like proton pump inhibitors) further deplete magnesium. Subclinical deficiency is common but often undetected because serum magnesium (the standard blood test) reflects only 1% of total body stores.
Magnesium is often called the 'relaxation mineral' because of its role in muscle relaxation, GABA receptor function, and HPA axis regulation. It is one of the most commonly recommended supplements across virtually all health disciplines.
Key benefits
Muscle and nerve function
Magnesium contributes to normal muscle function and normal functioning of the nervous system. It regulates neuromuscular signals and muscle contraction.
Energy production
Magnesium contributes to normal energy-yielding metabolism. It is required for ATP synthesis and activation.
Sleep quality
Magnesium activates the parasympathetic nervous system and regulates GABA receptors, which may support sleep onset and quality.
Bone health
Magnesium contributes to the maintenance of normal bones. About 60% of body magnesium is stored in bones.
Vitamin D activation
Magnesium is a required cofactor for the enzymes that convert Vitamin D to its active form. Without adequate magnesium, Vitamin D supplementation may be less effective.
Available forms
Magnesium Glycinate
Chelated with glycine. Well-absorbed, gentle on the stomach. Preferred for sleep and anxiety support due to glycine's calming effects.
Magnesium Threonate
Crosses the blood-brain barrier. Specifically studied for cognitive function and brain magnesium levels. More expensive.
Magnesium Citrate
Good bioavailability. Can have a mild laxative effect at higher doses. Common and affordable.
Magnesium Oxide
Cheapest form. Poorly absorbed (~4% bioavailability). Primarily useful as an osmotic laxative, not for correcting deficiency.
Magnesium Taurate
Chelated with taurine. Studied for cardiovascular support. Taurine itself supports heart rhythm.
Magnesium Malate
Chelated with malic acid. Sometimes preferred for energy production and muscle pain, as malic acid is involved in the Krebs cycle.
Food sources
- Dark leafy greens (spinach, Swiss chard)
- Nuts (almonds, cashews)
- Seeds (pumpkin, sunflower)
- Dark chocolate (70%+ cacao)
- Avocado
- Legumes (black beans, edamame)
Signs of deficiency
- Muscle cramps and spasms
- Fatigue and weakness
- Poor sleep quality
- Anxiety and irritability
- Heart palpitations
- Numbness and tingling
Upper intake limit
350 mg/day from supplements (NIH). Higher amounts from food are fine. The upper limit refers to supplemental magnesium due to the laxative effect.
Research summary
Strong evidence for muscle cramps, blood pressure reduction, and Vitamin D activation. Good evidence for sleep quality (especially glycinate/threonate forms) and migraine prevention. Emerging evidence for anxiety, depression, and insulin sensitivity. Most adults would benefit from magnesium supplementation given the widespread insufficiency.
Known interactions (6)
Calcium and magnesium compete at high doses
High-dose magnesium may reduce zinc absorption
Magnesium activates Vitamin D
Complementary sleep support through different systems
B6 may enhance magnesium cellular uptake
No conflict — magnesium creatine chelate is a supplement form
Check your full stack
for interactions.
See what competes, what combines well, and when to take everything. Every interaction cites a published source.
Stack
6 supplements
Stack review
1 flagZinc and Iron compete for the same absorption pathway. Take at least 2 hours apart.
Supplements
This information is for educational purposes only. It is not medical advice and does not diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional.