Magnesium
Also known as Magnesium glycinate, Magnesium citrate
Magnesium is a cofactor for hundreds of enzymatic reactions, including energy production, muscle relaxation, blood-sugar control, and nervous-system regulation. Modern diets are frequently low in it, and deficiency can show up as cramps, poor sleep, and tension.
Benefits
Improves sleep quality
ModerateSupports GABA activity and nervous-system calming, which may help with sleep onset and quality.
Eases muscle cramps and tension
ModerateImportant for normal muscle contraction and relaxation.
Supports blood-sugar regulation
ModerateHigher magnesium intake is associated with better insulin sensitivity.
Pros & cons
Pros
- Multiple well-tolerated forms
- Broadly beneficial and inexpensive
- Glycinate form is gentle and calming
Cons
- Oxide form is poorly absorbed
- High doses can be laxative
Side effects
Digestive upset
Citrate and oxide forms can cause loose stools at higher doses.
Excess in kidney disease
Those with impaired kidneys can accumulate magnesium and should be cautious.
How to take it
Typical dose
200–400 mg elemental magnesium per day
Timing
Evening for sleep support; with food to reduce GI upset
Tip: Glycinate and malate are gentle on digestion; threonate is studied for cognition.
Forms: which one to choose
The main forms of Magnesium compared by absorption, tolerability, and best use.
Magnesium Glycinate
Most popularHigh absorptionBest for: Sleep, stress, and relaxation · Calming and least likely to loosen stool
Read about Magnesium GlycinateMagnesium Citrate
High absorptionBest for: Everyday repletion and constipation · Well absorbed; can loosen stool
Read about Magnesium CitrateMagnesium Malate
High absorptionBest for: Daytime energy and muscle comfort · Often taken earlier in the day
Read about Magnesium MalateMagnesium L-Threonate
Moderate absorptionBest for: Cognition and brain health · Reaches the brain; low elemental magnesium; pricier
Read about Magnesium L-ThreonateMagnesium Taurate
High absorptionBest for: Heart, blood pressure, and blood sugar · Paired with taurine, which is also calming
Read about Magnesium TaurateMagnesium Oxide
Low absorptionBest for: Occasional constipation and lowest cost · Poorly absorbed for actual repletion
Read about Magnesium OxideWhat the research says
[1]Magnesium and sleep
ModerateReviews suggest modest improvements in sleep parameters, especially in older adults or those with low intake.
Systematic reviews · 2021PubMed[2]Magnesium and metabolic health
ModerateHigher dietary magnesium is consistently associated with improved insulin sensitivity and lower type-2 diabetes risk.
Cohort studies & meta-analyses · 2020PubMed[3]Magnesium for muscle cramps and recovery
PreliminaryA Cochrane review found magnesium unlikely to provide clinically meaningful cramp prevention in older adults; evidence in pregnancy and exercise-related cramps is mixed.
Cochrane review · 2020PubMed[4]Magnesium and blood pressure
ModerateMeta-analyses show modest reductions in blood pressure with magnesium supplementation.
Hypertension meta-analyses · 2017PubMed[5]Magnesium for migraine prevention
ModerateRandomized trials support magnesium for reducing migraine frequency in some patients.
Neurology trials · 2018PubMed[6]Magnesium, anxiety, and stress
PreliminaryReviews link low magnesium status to higher subjective anxiety and stress measures.
Nutrition reviews · 2017PubMed
Watch the breakdown
Our evidence review of Magnesium in video form — same research, ten minutes.
How Magnesium interacts
Synergies, absorption effects, and cautions between Magnesium and other supplements in the matrix.
Magnesium and its direct connections · click a node to open its guide
A sleep pairing with a built-in shortcut: magnesium glycinate is magnesium bound to glycine, so that form already delivers both. A standalone 3 g dose before bed (the amount sleep studies used) tops up the glycine, lowering core body temperature while magnesium relaxes muscles and calms the nervous system.
Compare the pairingRequired to activate vitamin D; low magnesium reduces how well D3 works.
Compare the pairingBoth calm the nervous system, a popular combination for relaxation and sleep.
Compare the pairingMagnesium is a required cofactor for many methylation enzymes; low magnesium can limit the benefit of folate supplementation.
Compare the pairingMagnesium is a cofactor for the enzyme that converts tryptophan to 5-HTP; deficiency limits serotonin synthesis.
Compare the pairingMagnesium supports vascular smooth muscle relaxation alongside nitric oxide from arginine.
Compare the pairingRiboflavin and magnesium are a commonly recommended migraine-prevention pair.
Compare the pairingBoron reduces urinary magnesium loss and supports magnesium status, complementing magnesium supplementation.
Compare the pairingBoth support cardiovascular function and a calm nervous system, and the pair is common in relaxation and recovery formulas.
Compare the pairingMagnesium supports GABA activity and relaxation while melatonin signals sleep timing — a popular, well-tolerated sleep stack that targets complementary mechanisms.
Compare the pairingMagnesium is required for thiamine-dependent enzymes to function properly.
Compare the pairingMagnesium supports many of the same mitochondrial and stress pathways as B3.
Compare the pairingMagnesium supports the same stress-response and energy pathways that rely on CoA.
Compare the pairingMagnesium and B6 are frequently combined for sleep, mood, and PMS support.
Compare the pairingOften combined for sleep and mood; magnesium supports the broader serotonin and relaxation pathways.
Compare the pairingMagnesium supports testosterone, stress resilience, and sleep alongside Tongkat Ali.
Compare the pairingBoth support mitochondrial energy production and cardiovascular function, a common pairing for heart health and fatigue.
Compare the pairingMagnesium supports many of the same enzymatic and neurological pathways as B12.
Compare the pairingCompete for absorption at very high single doses; keep intake balanced rather than mega-dosing one.
Compare the pairingFrequently asked questions
What is Magnesium used for?
Magnesium is most commonly used for sleep, stress, muscle function, and blood sugar. Supports GABA activity and nervous-system calming, which may help with sleep onset and quality.
How much Magnesium should I take?
A typical dose is 200–400 mg elemental magnesium per day. Glycinate and malate are gentle on digestion; threonate is studied for cognition. Start at the lower end and confirm the right dose for you with a healthcare professional.
When is the best time to take Magnesium?
Recommended timing: Evening for sleep support; with food to reduce GI upset.
What are the side effects of Magnesium?
Reported side effects include digestive upset and excess in kidney disease. Citrate and oxide forms can cause loose stools at higher doses.
Who should be careful with Magnesium?
Usually taken for better sleep, but a minority of people find the glycinate form paradoxically stimulating (glycine can be mildly activating for them); if it disrupts your sleep, take it earlier in the day or switch to citrate or malate. Speak with a healthcare professional if any of these apply to you.
Important cautions
- Usually taken for better sleep, but a minority of people find the glycinate form paradoxically stimulating (glycine can be mildly activating for them); if it disrupts your sleep, take it earlier in the day or switch to citrate or malate.
More Minerals
Boron
A trace mineral for bone, hormones, and mineral metabolism.
Calcium
The primary structural mineral of bones and teeth.
Copper
The trace mineral that balances zinc.
Supports these foundations
Magnesium can help reinforce these lifestyle foundations, but it works best on top of them, not in place of them.