Magnesium
Magnesium
TL;DR
Magnesium is a cofactor in more than 300 enzyme reactions. Supplemental doses of 200-400 mg elemental magnesium daily have the strongest support for constipation, migraine prevention, and sleep quality, particularly in people with low dietary intake.
Ideal For
- Low dietary intake of greens, legumes, nuts and whole grains
- Frequent or chronic constipation
- Migraine sufferers seeking a prophylactic
- Difficulty falling asleep or restless sleep
- Type 2 diabetes or metabolic syndrome, where urinary losses are higher
- Regular users of proton pump inhibitors or loop diuretics
Avoid If
- Chronic kidney disease or reduced eGFR
- Myasthenia gravis
- Second- or third-degree heart block
- Taking oral bisphosphonates, tetracyclines or quinolones without separating doses
Frequently Asked Questions
Overview
Magnesium is the fourth most abundant mineral in the body. About 25 g is stored in an adult, with 50-60% in bone and most of the remainder inside soft tissue cells. Less than 1% circulates in serum, which is why a normal serum magnesium result does not rule out depletion — the kidneys defend blood levels by pulling from bone and tissue stores long before a blood test moves.
Dietary intake in Western countries frequently falls below the RDA (400-420 mg/day for adult men, 310-320 mg/day for adult women). Refined grains lose most of their magnesium in processing, and the richest sources — legumes, nuts, seeds, whole grains, and leafy greens — are underconsumed. Habitual low intake is common rather than exotic, which is part of why supplementation produces measurable effects in trials.
Clinically, the evidence is strongest where magnesium acts pharmacologically rather than nutritionally. Magnesium oxide and citrate draw water into the bowel and relieve constipation reliably. Magnesium for migraine prophylaxis is recommended by several headache societies on the basis of randomized trials. For sleep and anxiety the trials are smaller and shorter, and the effect appears largest in older adults and in those with poor baseline intake.
Note the distinction between the RDA and the tolerable upper intake level: the UL of 350 mg/day applies only to supplemental magnesium, not to magnesium from food. Above that threshold, loose stools are the usual dose-limiting side effect.
How It Works
- Acts as a cofactor for over 300 enzymes, including those governing ATP production, protein synthesis, and DNA repair
- Blocks the NMDA receptor and potentiates GABA-A signalling, which is the proposed basis for its calming and sleep effects
- Competes with calcium at vascular and skeletal muscle sites, promoting smooth-muscle relaxation and vasodilation
- Stabilises cortical spreading depression and modulates nitric-oxide release, the leading mechanistic account for migraine prophylaxis
- Poorly absorbed forms (oxide, sulfate) retain water osmotically in the bowel lumen, producing a laxative effect
Quick Facts
- Involved in over 300 enzymatic reactions in the body
- Essential for muscle and nerve function
- Supports healthy heart rhythm and blood pressure
- Helps regulate blood sugar and energy metabolism
- Many people have insufficient magnesium intake
Benefits & Outcomes
GABA Enhancement
Cheap, well tolerated, and mechanistically sound, particularly if intake is low.
Parasympathetic Activation
Magnesium supports sleep depth and muscle relaxation, which shows up as better overnight HRV for many people.
Sleep Maintenance
Magnesium has modest sleep evidence, mostly in older adults and those with low intake.
Constipation Relief
Magnesium is a reliable, fast-acting option for constipation and works within a day for most people.
DHEA Enhancement
No meaningful evidence links magnesium to DHEA levels; its hormonal relevance is chiefly to testosterone in deficient men.
Anger Management
Magnesium plausibly reduces irritability, particularly where intake is low.
Oxytocin Enhancement
Magnesium supports calm and receptor function generally, but there is no human evidence it raises oxytocin.
Insulin Sensitivity
Magnesium improves insulin sensitivity where status is low, which is common in insulin resistance.
Heart Health Support
Magnesium supports vascular tone and rhythm; deficiency correction has clear cardiovascular rationale.
Lactic Acid Clearance
Magnesium supports muscle function but does not meaningfully change lactate clearance in replete athletes.
Enhanced Athletic Performance
Magnesium matters where intake is low, which is common in heavy trainers.
Testosterone Support
Magnesium shows small testosterone signals in athletes, with weak overall evidence.
Intestinal Motility
Magnesium is the most reliable supplement for slow transit, working osmotically within a day or two.
Irritability Reduction
Magnesium takes the edge off irritability, particularly where intake is low or stress is high.
Jet Lag Recovery
Magnesium has no circadian-shifting effect and is not a jet lag treatment.
Migraine Prevention
Magnesium is an AAN guideline-listed migraine preventive with RCT evidence for reducing attack frequency, especially in menstrual migraine and migraine with aura.
Nerve Pain Relief
Plausible NMDA mechanism, weak clinical evidence for nerve pain.
Night Sweats Reduction
Helps sleep continuity, not the sweats themselves.
Obsessive Thought Reduction
Magnesium may reduce the anxiety that fuels rumination, but there is no evidence it treats obsessions.
PMS Symptom Relief
Magnesium helps bloating, cramping and fluid retention, and pairs well with B6.
Post-Exercise Soreness Reduction
Magnesium helps if you are deficient or cramping, but it is not a reliable soreness treatment.
Pregnenolone Support
Magnesium supports hormone synthesis indirectly through sleep and stress rather than any direct steroidogenic effect.
Sex Hormone Binding Globulin
Magnesium may slightly reduce testosterone binding, but the practical effect is small.
Shift Work Adaptation
Magnesium may improve daytime sleep quality, particularly if intake is low.
Bone Health Support
Magnesium is required for vitamin D activation and parathyroid hormone regulation.
Melatonin Production
Magnesium supports the enzymatic conversion of serotonin to melatonin and has RCT evidence for improving sleep quality in deficient and older adults.
Menstrual Cramp Relief
Magnesium reduced dysmenorrhea pain and analgesic need in RCTs, with pre-menstrual dosing showing the strongest effects.
Panic Attack Prevention
Magnesium has small anxiolytic effects that may reduce background arousal, but no panic-specific evidence.
Social Anxiety Reduction
Magnesium has weak anxiety evidence, most relevant where intake is low.
ATP Production Enhancement
ATP is biologically active only as Mg-ATP, so repletion matters.
Pain Relief
Magnesium helps cramping and some neuropathic pain but does little for general inflammatory pain.
Back Pain Relief
Plausible role in muscle tension and neuropathic components; direct back-pain RCT evidence is thin.
Headache Relief
Magnesium is a guideline-supported migraine preventive, with the strongest evidence for menstrual migraine and deficiency states.
Hydration Support
Magnesium supports cellular hydration and muscle function; deficiency impairs electrolyte handling, but acute rehydration depends on sodium and fluid.
Diabetes Incidence
Good supporting evidence, especially with low dietary intake or prediabetes.
Glucose Tolerance
Solid supporting evidence, especially with low intake or prediabetes.
Electrolyte Balance
Clearly useful when intake or status is low — a large share of the population.
Deep Sleep Enhancement
Meta-analysis supports modest sleep quality improvements, strongest in deficient or older populations.
Improved Sleep Quality
A first-line sleep supplement with good evidence, a strong safety profile and high deficiency prevalence.
Stress Resilience
Well-supported for stress and mild anxiety, especially when dietary intake is low.
Heart Rate Variability
Plausible via sleep and autonomic tone, thinly studied directly.
Ghrelin Regulation
No direct evidence that magnesium alters ghrelin; any appetite benefit is indirect via sleep.
Muscle Relaxation & Cramp Relief
Positive RCT evidence in pregnancy-related leg cramps and in deficiency; Cochrane finds weaker evidence for idiopathic nocturnal cramps in older adults.
Stress & Anxiety Reduction
Magnesium has weak anxiety evidence outside of low intake.
Blood Pressure Regulation
Magnesium supplementation lowers blood pressure by a small but real margin, with the largest effect in hypertensive or magnesium-deficient adults.
Mental Clarity
There is no reliable trial evidence that magnesium improves cognitive performance in people with adequate magnesium status.
Health Concerns Addressed
Alcohol Use Disorder
Correcting magnesium is standard supportive care in alcohol use disorder, particularly during withdrawal. It treats a real deficiency rather than the disorder itself.
Painful Periods
Magnesium has genuine randomised trial support for reducing period-cramp severity — a Cochrane review rates the evidence favourable — making it one of the best-evidenced supplement options for dysmenorrhoea alongside heat and NSAIDs.
Premenstrual Bloating
Magnesium has specific randomised trial evidence for reducing premenstrual fluid retention — one of the better supplement options for cyclical bloating, alongside salt reduction in the premenstrual week.
Substance Use Disorder
Likely important as electrolyte repletion during alcohol withdrawal, not as a treatment for the disorder.
Arrhythmia
Essential when low, unproven when normal. Test-guided repletion is evidence-based; blanket supplementation for palpitations is not.
Muscle Tension
Magnesium is mechanistically plausible for muscle tension and many people report benefit, but trial evidence for chronic tension is thin — the strongest data remain for deficiency states and nocturnal leg cramps. Movement, heat, and stress reduction are better supported.
Chronic Pain
NMDA receptor blockade gives a credible mechanism for central sensitisation, but oral trials in chronic pain are small and inconsistent.
Nervousness
Low risk and cheap, but the evidence is weak and inconsistent.
Chest Tightness
Reasonable adjunct for asthma- or anxiety-pattern tightness after cardiac causes are excluded; never a first response to undiagnosed chest tightness.
Myasthenia Gravis
Magnesium is a caution item in myasthenia gravis, not a treatment — it physiologically reduces acetylcholine release at the neuromuscular junction, the exact signal already failing in MG, and intravenous magnesium has triggered myasthenic crises.
Heart Palpitations
Magnesium reduces palpitations when levels are low — from diuretics, poor intake or heavy losses — and correcting deficiency genuinely calms ectopy. For people with normal levels, evidence for benefit is weak, and it is not a treatment for true arrhythmias like SVT or atrial fibrillation.
Panic Attacks
A low-risk adjunct with weak, indirect evidence. It will not substitute for exposure-based CBT, which is the treatment that changes the course of panic.
Jaw Pain
Magnesium supports muscle relaxation and neuromuscular function, making it a plausible adjunct for jaw pain driven by clenching and muscle overuse. Direct trial evidence for TMD is thin; support is largely mechanistic.
Panic Disorder
Insufficient evidence for panic disorder specifically; reasonable only to correct deficiency.
Post-Exertional Malaise
Magnesium is frequently suggested for ME/CFS and PEM, but evidence is thin and nothing addresses the exertion-crash mechanism — pacing within your energy envelope remains the only management approach with guideline support.
Teeth Grinding
Magnesium is sometimes suggested for bruxism because of its role in muscle relaxation and sleep quality, but direct trial evidence for teeth grinding is thin. A fitted mouthguard and stress/sleep management remain the primary interventions.
Water Retention
One positive RCT in premenstrual fluid retention; no evidence for other causes of oedema.
Shakiness
No trial evidence supports magnesium for ordinary adrenergic shakiness.
TMJ Disorder
Plausible for masticatory muscle tension and sleep quality, but no trial has tested it in temporomandibular disorder.
Sugar Cravings
The popular claim that chocolate craving signals magnesium deficiency is not supported by evidence.
Insomnia
Worth trying at 200-350 mg of glycinate before bed, especially if your diet is low in greens, legumes and nuts. Expect a modest shortening of sleep onset rather than a transformation.
Magnesium Deficiency
This is direct replacement of a deficient nutrient. Choose glycinate or citrate — oxide is poorly absorbed and mainly acts as a laxative.
Chronic Constipation
Reliably effective for occasional constipation at 400-1000 mg of magnesium oxide or citrate. Straightforward, cheap and fast-acting — but not a solution for chronic constipation without a clinician.
Frequent Headaches
A genuine prophylactic option for migraine, particularly menstrual migraine and migraine with aura. Not useful for an attack already in progress, and it needs three months of consistent use.
Poor Sleep Quality
Magnesium modestly improves subjective sleep quality and sleep onset time, especially in older adults and people with low intake. Evidence quality is low-to-moderate, but glycinate at 200-400mg before bed is inexpensive and well tolerated.
Kidney Stones
Magnesium inhibits calcium oxalate crystallisation and is often combined with potassium citrate, but standalone evidence is thin compared with fluid and sodium changes.
Hearing Loss
The interesting evidence is preventive: magnesium before loud noise exposure reduced threshold shifts in military recruits. It does nothing for established loss.
Tremors
Magnesium only helps tremor when deficiency is the cause, which is uncommon. There is no trial evidence for essential tremor or Parkinsonian tremor.
Muscle Cramps
Low value for typical night cramps in older adults. More defensible in pregnancy-related cramps or where intake is genuinely poor.
Prediabetes
Worth attention if your intake is poor or you take diuretics or PPIs. A small lever, not a treatment.
Fibromyalgia
Small trials of magnesium, mostly as magnesium malate combined with malic acid, show inconsistent effects on fibromyalgia pain.
Frequent Urination
Not recommended as a treatment. Bladder training and pelvic floor work have far better evidence for the same symptoms.
Premenstrual Syndrome (PMS)
Magnesium 200-360 mg/day started in the luteal phase reduces PMS mood symptoms, fluid retention and cramping in repeated small trials, especially combined with vitamin B6.
Digestive Issues
Magnesium oxide and citrate are effective, well-characterised osmotic laxatives for constipation-predominant digestive complaints; they do not address reflux, bloating or IBS pain.
Hearing Changes
Small military trials suggest magnesium blunts temporary noise-induced threshold shift. Not a substitute for hearing protection and not a treatment for established loss.
Anxiety
Small anxiety improvements in trials, with the clearest signal in people who are magnesium-depleted or have premenstrual anxiety.
Chronic Fatigue Syndrome (ME/CFS)
Interest in magnesium for ME/CFS dates to a small 1991 trial reporting improved energy after intramuscular injection. That result has not been reliably replicated with oral dosing, so the case rests largely on correcting documented deficiency.
Metabolic Syndrome
Higher magnesium intake is consistently associated with lower metabolic syndrome prevalence, and supplementation modestly improves insulin sensitivity, blood pressure and triglycerides. Effects on any single component are small, but they align in a favourable direction.
ADHD (Attention Deficit Hyperactivity Disorder)
Children with ADHD show lower average magnesium status in observational work, and small trials pairing magnesium with vitamin B6 report symptom improvement. The trials are methodologically weak, so this is best viewed as correcting a deficiency rather than treating ADHD.
Menopause
Magnesium may help menopausal sleep disturbance and mood, but the evidence for vasomotor symptoms is weak and the largest trial was negative.
Chronic Muscle Soreness
Magnesium is genuinely required for muscle relaxation, but direct trials of supplementation for exercise-induced soreness are few and inconsistent. Benefit is most plausible in athletes with high sweat losses or low intake.
Low Testosterone (Male Hypogonadism)
A small trial in athletes found magnesium raised free and total testosterone, with the larger rise in those also exercising. Evidence is limited to a handful of small studies and observational correlations, so effects are probably modest and largest when status is low.
Blood Sugar Dysregulation
Magnesium supplementation modestly improves fasting glucose and insulin sensitivity, with the largest effects in people who are magnesium-deficient or insulin-resistant. Meta-analyses support a real but small effect; it is a supporting measure, not a glucose-lowering therapy.
Endometriosis
No clinical trials of magnesium for endometriosis exist; use is extrapolated from its effect on general menstrual cramping.
Supporting Research85 studies
Effects of Magnesium Supplementation on Blood Pressure: A Meta-Analysis of Randomized Double-Blind Placebo-Controlled Trials
Dibaba DT, Xun P, Song Y +3 more
Magnesium supplementation reduced systolic blood pressure by 2.00 mmHg and diastolic by 1.78 mmHg overall. Reductions were larger with higher doses and longer duration, and in participants with lower baseline magnesium status or higher baseline blood pressure. Serum magnesium rose by 0.05 mmol/L, and the increase correlated with the blood pressure reduction.
The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial
Abbasi B, Kimiagar M, Sadeghniiat K +3 more
Magnesium supplementation significantly improved PSQI scores (p<0.05) Significant increase in sleep time by 42 minutes (p<0.001) Improved sleep efficiency from 74% to 85% (p<0.001) Reduced early morning awakening frequency (p<0.01) Increased serum melatonin concentration (p<0.05) Decreased serum cortisol levels (p<0.05) Reduced sleep onset latency by 17 minutes
Effect of magnesium supplementation on blood pressure: a meta-analysis
Kass L, Weekes J, Carpenter L
Magnesium supplementation produced a small but statistically significant reduction in blood pressure: systolic fell by about 3-4 mmHg and diastolic by about 2-3 mmHg, with larger effects (up to roughly 5.6/2.8 mmHg) at doses above 370 mg/day. Effects were most evident in hypertensive participants.
Alternative medical interventions used in the treatment and management of myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia
Porter NS, Jason LA
Systematic review of 70 studies of complementary and alternative interventions in ME/CFS and fibromyalgia found the strongest supporting signals for magnesium, L-carnitine and S-adenosylmethionine, while homeopathy, massage and most botanical treatments had insufficient or conflicting evidence.
Efficacy of alginate-based reflux suppressant and magnesium-aluminium antacid gel for treatment of heartburn in pregnancy: a randomized double-blind controlled trial
Meteerattanapipat P, Phupong V
There was no difference between alginate-based reflux suppressant and magnesium-aluminium antacid gel in improvement of heartburn frequency (80% vs 88%).
Dietary magnesium intake and the risk of cardiovascular disease, type 2 diabetes, and all-cause mortality: a dose-response meta-analysis of prospective cohort studies
Fang X, Wang K, Han D +2 more
Comparing highest with lowest dietary magnesium intake, risk was reduced for total cardiovascular disease (RR 0.85), ischaemic heart disease (RR 0.78), type 2 diabetes (RR 0.81) and stroke (RR 0.88). Dose-response analysis showed roughly a 10% lower risk of coronary heart disease and 12% lower stroke risk, and a 19% lower risk of type 2 diabetes, per 100 mg/day increment. No significant association was found with total cardiovascular mortality or all-cause mortality.
Magnesium and Cardiovascular Disease
DiNicolantonio JJ, Liu J, O'Keefe JH
Review evidence links subclinical magnesium deficiency to hypertension, arrhythmias, arterial calcification, endothelial dysfunction and increased cardiovascular mortality, and argues that serum magnesium is an insensitive marker that hides widespread inadequacy.
A review of treatment of premenstrual syndrome and premenstrual dysphoric disorder
Kaur G, Gonsalves L
Calcium showed the most consistent benefit for irritability and mood symptoms; magnesium and B6 evidence was weaker and mixed.
Magnesium Status and Stress: The Vicious Circle Concept Revisited
Pickering G, Mazur A, Trousselard M +1 more
Stress increases urinary magnesium excretion and depletes magnesium stores, while magnesium deficiency amplifies HPA axis activation and stress hormone release - a self-reinforcing vicious circle. Mechanistically, magnesium antagonises NMDA receptors, supports GABAergic transmission and dampens cortisol release. Supplementation trials, particularly magnesium combined with vitamin B6, show reduced perceived stress scores in individuals with severe stress and low magnesium status.
Interventions for leg cramps in pregnancy
Luo L, et al
Across 8 trials (576 women), oral magnesium may reduce leg cramp frequency versus placebo in some trials but results were inconsistent; oral calcium showed no clear benefit; vitamin B complex and vitamin C evidence was very low certainty. No intervention was supported by high-quality evidence.
Muscle cramps and magnesium deficiency: case reports
Bilbey DL, Prabhakaran VM
Both patients presented with persistent, severe muscle cramps and pain attributable to documented magnesium deficiency, and symptoms resolved following magnesium repletion. The authors argue magnesium deficiency is more common than generally recognised and is often missed because serum magnesium poorly reflects total body stores.
Proton pump inhibitors, hypochlorhydria and micronutrient absorption: a systematic review
Heidelbaugh JJ
Long-term acid suppression was associated with impaired absorption of vitamin B12, iron and magnesium, supporting the role of gastric acid in mineral uptake.
Multivitamin and mineral supplementation and micronutrient status in adults: a systematic review
Blumberg JB, Frei BB, Fulgoni VL +2 more
Supplement users had markedly lower prevalence of inadequate intakes for vitamins A, C, D, E, calcium and magnesium.
Growing Evidence for Human Health Benefits of Boron
Nielsen FH, Meacham SL
Boron intakes above about 1 mg/day are associated with improved calcium and magnesium metabolism, bone strength and reduced inflammatory markers in experimental and observational work.
Nutrition treatment of deficiency and malnutrition in chronic pancreatitis: a review
Duggan SN, O'Sullivan M, Feehan S
Fat-soluble vitamin (A, D, E, K), vitamin B12, magnesium and zinc deficiencies are common and often unrecognised; enzyme replacement plus targeted repletion is recommended.
Pivotal role of boron supplementation on bone health: A narrative review
Rondanelli M, Faliva MA, Peroni G +1 more
Available human studies suggest boron influences calcium, magnesium and vitamin D metabolism relevant to bone, but no dosing recommendation can be established from current data.
The Effect of Magnesium Supplementation on Primary Insomnia in Elderly
Abbasi B, Kimiagar M, Sadeghniiat K +1 more
Magnesium supplementation significantly improved PSQI scores (p<0.05) Significant increase in sleep time by 42 minutes (p<0.001) Improved sleep efficiency from 74% to 85% (p<0.001) Reduced early morning awakening frequency (p<0.01) Increased serum melatonin concentration (p<0.05) Decreased serum cortisol levels (p<0.05) Reduced sleep onset latency by 17 minutes
Boron and bone health: a systematic review
Hunt, C.D.
This review of human and animal data found boron influences calcium, magnesium and vitamin D metabolism and steroid hormone levels, with depletion-repletion studies suggesting boron may reduce urinary calcium loss, but no clinical trials demonstrating reduced fracture risk or improved bone mineral density in humans.
Magnesium in Prevention and Therapy
Gröber U, Schmidt J, Kisters K
Review of magnesium physiology and therapeutics: deficiency is common and poorly detected by serum levels, and supplementation is used in migraine prophylaxis, eclampsia, arrhythmia, asthma and insulin resistance. Organic salts (citrate, glycinate) show better bioavailability than magnesium oxide.
Comparison between Acupuncture and Nutraceutical Treatment with Migratens in Patients with Fibromyalgia Syndrome
Schweiger V
In 55 patients with fibromyalgia, both acupuncture and the nutraceutical Migratens (containing coenzyme Q10, magnesium, riboflavin and related nutrients) over 12 weeks reduced pain, fatigue and Fibromyalgia Impact Questionnaire scores versus baseline, with acupuncture producing faster relief and comparable outcomes at study end.
Superiority of magnesium and vitamin B6 over magnesium alone on severe stress in healthy adults with low magnesemia: A randomized, single-blind clinical trial
Pouteau E, et al.
These findings suggest oral Mg supplementation alleviated stress in healthy adults with low magnesemia and the addition of vitamin B6 to Mg was not superior to Mg supplementation alone.
Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study
Walker AF, et al.
We conclude that a daily supplementation with Mg citrate shows superior bioavailability after 60 days of treatment when compared with other treatments studied.
Effects of selected dietary supplements on migraine prophylaxis: A systematic review and dose-response meta-analysis of randomized controlled trials
Talandashti MK, Shahinfar H, Delgarm P +1 more
Magnesium supplementation reduced migraine attacks (mean difference (MD) = -2.51), severity (MD = -0.88), and the monthly migraine days (MD = -1.66) compared with the control group.
A Randomized Double-blind Placebo-controlled Trial on the Effect of Magnesium Oxide in Patients With Chronic Constipation
Mori S
Our placebo-controlled study demonstrated that MgO was effective treatment for improving defecation status and shortened CTT in Japanese CC patients with mild to moderate symptoms.
Magnesium supplementation for the treatment of restless legs syndrome and periodic limb movement disorder: A systematic review
Marshall NS
We were unable to make a conclusion as to the effectiveness of magnesium for RLS/PLMD.
Magnesium for acute traumatic brain injury
Magnesium administration did not reduce mortality or morbidity after acute traumatic brain injury.
Is magnesium citrate treatment effective on pain, clinical parameters and functional status in patients with fibromyalgia?
Bagis S
The magnesium citrate treatment was only effective tender points and the intensity of fibromyalgia.
Short-Term Magnesium Therapy Alleviates Moderate Stress in Patients with Fibromyalgia: A Randomized Double-Blind Clinical Trial
Macian N
These findings show, for the first time, that magnesium improves mild/moderate stress and reduces the pain experience in fibromyalgia patients.
Intravenous magnesium sulfate for treating adults with acute asthma in the emergency department
Kew KM, Kirtchuk L, Michell CI
Intravenous magnesium reduced hospital admissions and improved lung function in adults with acute severe asthma.
Effect of Magnesium Supplementation on Depression and Anxiety
Tarleton EK, Littenberg B, MacLean CD +1 more
Magnesium is effective for mild-to-moderate depression in adults. It works quickly and is well tolerated without the need for close monitoring for toxicity.
Effect of magnesium sulfate iontophoresis on myofascial trigger points in the upper fibres of the trapezius
Ibrahim NA, et al.
MgSO4 iontophoresis is effective in improving pain level, neck ROM, and neck function in subjects with active MTrPs on the dominant upper fiber of trapezius.
Effect of Magnesium on Ventricular Extrasystoles in Children
Uysal F, et al.
Oral Mg therapy was found to be effective at suppressing VES in children regardless of serum Mg levels. Large and randomized studies are needed to demonstrate the effect of magnesium on VES suppression.
Magnesium for acute traumatic brain injury
Arango MF
There is currently no evidence to support the use of magnesium salts in patients with acute traumatic brain injury.
Senna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled Trial
Morishita D, Tomita T
Magnesium oxide increased complete spontaneous bowel movements versus placebo, comparably to senna
Intravenous magnesium sulfate for asthma exacerbations in children: Systematic review with meta-analysis
Intravenous magnesium sulfate reduced hospital admission and improved respiratory scores in acute severe childhood asthma.
Magnesium sulfate in combination with nimodipine for the treatment of subarachnoid hemorrhage: a randomized controlled clinical study
et al
Magnesium sulfate combined with nimodipine can help reduce the incidences of CVS, delayed cerebral ischemia, secondary cerebral infarction, and neurologic deficits.
Intravenous magnesium prevents atrial fibrillation after coronary artery bypass grafting: a meta-analysis of randomized controlled trials
Gu WJ, Wu ZJ, Wang PF
Intravenous magnesium reduced postoperative atrial fibrillation (RR 0.64).
Magnesium supplementation and subjective anxiety: a systematic review
Boyle NB, Lawton C, Dye L
Existing evidence is suggestive of a beneficial effect of Mg on subjective anxiety in anxiety vulnerable samples. However, the quality of the existing evidence is poor.
A double-blinded randomised controlled study of the value of sequential intravenous and oral magnesium therapy in patients with chronic low back pain with a neuropathic component
Yousef AA, Al-deeb AE
Our findings show that a 2-week intravenous magnesium infusion followed by 4 weeks of oral magnesium supplementation can reduce pain intensity and improve lumbar spine mobility during a 6-month period in patients with refractory chronic low back pain with a neuropathic component.
Intravenous and nebulized magnesium sulfate for treating acute asthma in adults and children: a systematic review and meta-analysis
Shan Z
The use of intravenous magnesium sulfate, in addition to beta2-agonists and systemic steroids, in the treatment of acute asthma appears to produce benefits with respect to improve pulmonary function.
A synergistic effect of a daily supplement for 1 month of 200 mg magnesium plus 50 mg vitamin B6 for the relief of anxiety-related premenstrual symptoms: a randomized, double-blind, crossover study
De Souza MC, Walker AF, Robinson PA +1 more
A small synergistic effect of a daily dietary supplementation with a combination of Mg + vitamin B6 in the reduction of mild premenstrual anxiety-related symptoms was demonstrated during treatment of 44 women for one menstrual cycle.
The effect of magnesium supplementation on primary insomnia in elderly: a systematic review
Mah J, Pitre T
Magnesium supplementation decreased sleep onset latency by approximately 17 minutes, but the quality of evidence was very low.
Magnesium, Calcium, Potassium, Sodium, Phosphorus, Selenium, Zinc, and Chromium Levels in Alcohol Use Disorder: A Review
Baj J
Such knowledge helps to understand the mechanisms of chronic alcohol-use disorder and to progress and prevent withdrawal effects, also improving treatment strategies.
Red blood cell magnesium and chronic fatigue syndrome
Cox IM, Campbell MJ, Dowson D
Patients treated with magnesium claimed to have improved energy levels, better emotional state, and less pain.
Dietary supplements for dysmenorrhoea
Pattanittum P, et al.
There is no high quality evidence to support the effectiveness of any dietary supplement for dysmenorrhoea, and evidence of safety is lacking.
Nutritional factors associated with aggression
Lower magnesium status was among the nutritional deficiencies associated with higher aggression.
Effect of magnesium sulphate on fetal heart rate parameters: a systematic review
Nensi A, De Silva DA, von Dadelszen P +4 more
To examine the potential effects of intravenous magnesium sulphate (MgSO4) administration on antepartum and intrapartum fetal heart rate (FHR) parameters
The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial
Abbasi B, Kimiagar M, Sadeghniiat K +3 more
Higher magnesium intake was associated with better sleep quality and reduced insomnia symptoms.
Long-Term Effect of Magnesium Consumption on the Risk of Symptomatic Gallstone Disease Among Men
Tsai CJ, Leitzmann MF, Willett WC +1 more
Increasing consumption of magnesium appears to decrease the risk of symptomatic gallstones in men, although the underlying mechanisms remain unclear.
Association of magnesium intake with sleep duration and sleep quality: findings from the CARDIA study
Zhang Y, et al.
Mg intake was borderline associated with better sleep quality... Randomized controlled trials with objective measures of sleep are warranted to establish the potential causal inference.
Magnesium for skeletal muscle cramps
Garrison SR, et al.
It is unlikely that magnesium supplementation provides clinically meaningful cramp prophylaxis to older adults experiencing skeletal muscle cramps.
Effects of Intravenous and Oral Magnesium on Reducing Migraine: A Meta-analysis of Randomized Controlled Trials
Chiu HY, Yeh TH, Huang YC +1 more
Oral magnesium significantly alleviated the frequency and intensity of migraine (ORs = 0.20 and 0.27).
Herbs, vitamins and minerals in the treatment of premenstrual syndrome: a systematic review
Whelan AM, Jurgens TM, Naylor H
To identify herbs, vitamins and minerals advocated for the treatment of PMS and/or PMDD and to systematically review evidence from randomized controlled trials (RCTs) to determine their efficacy in reducing severity of PMS/PMDD symptoms.
Effect of magnesium supplementation on glucose metabolism in people with or at risk of diabetes: a systematic review and meta-analysis of double-blind randomized controlled trials
Veronese N, Watutantrige-Fernando S, Luchini C
Mg supplementation appears to have a beneficial role and improves glucose parameters in people with diabetes and also improves insulin-sensitivity parameters in those at high risk of diabetes.
The Role of Magnesium in Sleep Health: a Systematic Review of Available Literature
Higher magnesium status was associated with better sleep quality, though randomized evidence remains sparse.
Prophylactic magnesium does not prevent atrial fibrillation after cardiac surgery: a meta-analysis
Cook RC, et al.
This meta-analysis, restricted to well-conducted trials, does not support the prophylactic use of Mg to prevent AF after cardiac surgery.
Low serum magnesium and the development of atrial fibrillation in the community: the Framingham Heart Study
Khan AM, Lubitz SA, Sullivan LM
Lowest serum magnesium quartile had ~50% higher risk of incident atrial fibrillation.
Magnesium Bisglycinate Supplementation in Healthy Adults Reporting Poor Sleep: A Randomized, Placebo-Controlled Trial
Nature and Science of Sleep study authors
Magnesium bisglycinate supplementation modestly improved insomnia severity in adults reporting poor sleep quality.
Effect of oral magnesium supplementation on measures of airway resistance and subjective assessment of asthma control and quality of life
Kazaks AG, Uriu-Adams JY, Albertson TE
Oral magnesium improved methacholine-measured airway reactivity and asthma control.
Vitamins and Minerals for Migraine Prophylaxis: A Systematic Review and Meta-analysis
Okoli GN, Rabbani R, Kashani HH
Magnesium did not significantly decrease migraine severity (RoM -0.17 (-0.36 to 0.02)).
The impact of essential fatty acid, B vitamins, vitamin C, magnesium and zinc supplementation on stress levels in women: a systematic review
McCabe D, Lisy K
Magnesium, B vitamins and zinc showed modest improvements in perceived stress and mood-related irritability
Magnesium as a preventive treatment for paediatric episodic tension-type headache: results at 1-year follow-up
Grazzi L, et al
Although uncontrolled, these findings are encouraging and suggest that further, better controlled research investigations are warranted.
The Effect of Magnesium Supplementation on Primary Insomnia in Elderly: A Double-Blind Placebo-Controlled Clinical Trial
Abbasi B, Kimiagar M, Sadeghniiat K +3 more
Magnesium supplementation improved subjective measures of insomnia, sleep efficiency, sleep time, and sleep onset latency in elderly subjects.
Magnesium status and supplementation influence vitamin D status and metabolism: results from a randomized trial
Dai Q, et al.
Our findings suggest that optimal magnesium status may be important for optimizing 25(OH)D status.
Preventing Postoperative Atrial Fibrillation After Noncardiac Surgery: A Meta-analysis
Oesterle A, et al.
Magnesium (RR 0.73; 95% CI, 0.23 to 2.33) had no statistically significant effect on postoperative atrial fibrillation incidence.
Myasthenia Gravis: A Rare Neurologic Complication of Immune Checkpoint Inhibitor Therapy
Shames A, et al
Many medications, including fluroquinolone, aminoglycoside, magnesium sulfate, quinidine, and select beta blockers, are known to unmask or exacerbate symptoms of myasthenia gravis.
Oral magnesium intake reduces permanent hearing loss induced by noise exposure
Attias J, Weisz G, Almog S +7 more
NIPTS was significantly more frequent and more severe in the placebo group than in the magnesium group, especially in bilateral damages.
Improvement of migraine symptoms with a proprietary supplement containing riboflavin, magnesium and Q10: a randomized, placebo-controlled, double-blind, multicenter trial
Gaul C, Diener HC
Migraine days decreased with a riboflavin, magnesium and coenzyme Q10 combination, though the primary endpoint was not met
Hypomagnesemia and smooth muscle contractility: diffuse esophageal spasm in an old female patient
Iannello S, et al.
Our observation of a severe form of esophageal spasm, associated with hypomagnesemia, underlines the pathophysiological meaning of the plasma Mg level.
Magnesium and Sleep: A Systematic Review
Zhang Y, Chen C, Lu L +7 more
Systematic review examining associations between magnesium intake and sleep duration, quality, and disorders across multiple studies.
Effect of Oral Magnesium Supplementation on Physical Performance in Healthy Elderly Women Involved in a Weekly Exercise Program: A Randomized Controlled Trial
Veronese N, Berton L, Carraro S +2 more
Magnesium deficiency is associated with poor physical performance, but no trials are available on how magnesium supplementation affects elderly people physical performance.
The effect of melatonin, magnesium, and zinc on primary insomnia in long-term care facility residents in Italy: a double-blind, placebo-controlled clinical trial
Rondanelli M, et al.
The administration of nightly melatonin, magnesium, and zinc appears to improve the quality of sleep and the quality of life in long-term care facility residents with primary insomnia.
Serum Magnesium Concentrations in the United States-An Updated Population Reference Interval in Children and Adults
Jiao K, et al.
A substantial portion of the US population is at risk of CLMD [chronic latent magnesium deficiency].
Magnesium supplementation and sleep quality in older adults: a double-blind placebo-controlled trial
Abbasi B, Kimiagar M, Sadeghniiat K +3 more
Magnesium increased serum melatonin and improved sleep efficiency versus placebo
Association between dietary magnesium intake and gallstones: the mediating role of atherogenic index of plasma
Du W, Yan C, Wang Y +3 more
Higher dietary magnesium intake was inversely associated with gallstone prevalence, partly mediated by the atherogenic index of plasma.
Magnesium, vitamin D status and mortality: results from US National Health and Nutrition Examination Survey (NHANES) 2001 to 2006 and NHANES III
Deng X, et al.
Magnesium intake alone or its interaction with vitamin D intake may contribute to vitamin D status.
Magnesium supplementation and sympathetic nervous system activity: a systematic review of randomized trials
Zhang X, Li Y, Del Gobbo LC +3 more
Magnesium modestly reduced blood pressure and catecholamine-associated vascular tone
Examining the Effects of Supplemental Magnesium on Self-Reported Anxiety and Sleep Quality: A Systematic Review
Rawji A, et al.
Given the generally positive results across studies, the preponderance of preclinical evidence, and minimal side effects, however, supplemental magnesium is likely useful in the treatment of mild anxiety and insomnia, particularly in those with low magnesium status at baseline.
Antioxidant vitamins and magnesium and the risk of hearing loss in the US general population
Choi YH, Miller JM, Tucker KL +2 more
High intakes of beta-carotene or vitamin C combined with high magnesium compared with low intakes of both nutrients were significantly associated with lower (better) PTAs at high frequencies.
Magnesium status and neuroendocrine regulation of social and stress hormones: a review of clinical evidence
Boyle NB, Lawton C, Dye L
Magnesium produced modest reductions in subjective anxiety and stress-hormone reactivity
Effect of Magnesium Sulfate Added to Tincture of Opium and Buprenorphine on Pain and Quality of Life in Women with Dysmenorrhea: A Prospective, Randomized, Double-blind, Placebo-controlled Trial
Pirnia B, Masoudi R, Pirnia K +1 more
The primary outcomes showed that pain scores in magnesium (MAG) + opium tincture (OT) and MAG+ BUP groups showed a significant decrease compared with control group.
Magnesium supplementation and cardiac autonomic function: a randomized controlled trial
Wannamethee SG, Papacosta O, Lennon L +1 more
Higher magnesium status was associated with greater vagally mediated heart rate variability
An Oral Combination of Vitamins A, C, E, and Mg++ Improves Auditory Thresholds in Age-Related Hearing Loss
Alvarado JC, Fuentes-Santamaria V, Gabaldon-Ull MC +1 more
An oral combination of vitamins A, C, E, and Mg++ improves auditory thresholds in age-related hearing loss.
Effects of magnesium supplementation on premenstrual symptoms: a randomised double-blind crossover study
Facchinetti F, Borella P, Sances G +3 more
Magnesium reduced premenstrual mood changes and fluid-retention symptoms compared with placebo
Oral magnesium therapy improves endothelial function in patients with coronary artery disease
Shechter M, Sharir M, Labrador MJ +3 more
Brachial artery flow-mediated dilation improved and exercise-induced ischaemia measures were better with oral magnesium than placebo.
Safety Information
Potential Side Effects
Diarrhoea, nausea and abdominal cramping are the common, dose-dependent effects and typically appear above 350 mg of supplemental magnesium taken at once. They resolve on dose reduction or on switching to glycinate. Serious toxicity is essentially confined to people with impaired renal function.
Contraindications
Avoid supplemental magnesium in chronic kidney disease or any condition with reduced renal clearance — impaired excretion can lead to hypermagnesemia, which presents as hypotension, lethargy, confusion and, at extreme levels, cardiac arrest. Also avoid in myasthenia gravis and high-grade heart block. In pregnancy and lactation, intakes at the RDA (350-360 mg/day and 310-320 mg/day respectively) are considered appropriate; discuss higher supplemental doses with your provider.
Drug Interactions
- Bisphosphonates — magnesium reduces absorption; separate by at least 2 hours
- Tetracycline and quinolone antibiotics — form insoluble complexes; separate by 2-4 hours
- Loop and thiazide diuretics — increase urinary magnesium loss, raising requirements
- Proton pump inhibitors — prolonged use is associated with hypomagnesemia
- Levothyroxine — separate dosing by at least 4 hours
Pregnancy & Breastfeeding
Pregnancy: likely_safe
Breastfeeding: likely_safe
Dosage Guidelines
Dosage Used in Studies
200-400 mg
Best Time to Take
Evening, or split morning and evening
Best Form
Magnesium glycinate for repletion and sleep; citrate or oxide when a laxative effect is wanted
Bioavailability
Glycinate and threonate forms have superior bioavailability compared to oxide. Oxide form may cause digestive upset.
Dosing by Goal
| Goal | Dose | Notes |
|---|---|---|
| General repletion (adults) | 200-400 mg elemental magnesium daily | Take with food. Glycinate or citrate. The 350 mg upper limit applies to supplements only, not to food. |
| Migraine prophylaxis | 400-600 mg elemental magnesium daily | Doses in this range come from headache-society guidance and exceed the general upper limit; use under clinician supervision. Allow 8-12 weeks. |
| Sleep quality | 200-350 mg elemental magnesium, 30-60 minutes before bed | Glycinate is the usual form. Trials run 4-8 weeks. |
| Occasional constipation | 400-1000 mg magnesium oxide or citrate | Short-term use. Not appropriate for chronic use without a clinician, and contraindicated in renal impairment. |
Forms Compared
Glycinate (bisglycinate)
Best for Sleep, anxiety, general repletion
Chelated to glycine; well absorbed and the least likely to loosen stools. The usual first choice when the goal is not laxation.
Citrate
Best for Constipation, general repletion
Good bioavailability with a mild osmotic effect. Effective and inexpensive, but can cause loose stools above roughly 400 mg.
Oxide
Best for Constipation
Only about 4% absorbed. Cheap and widely sold, but a poor choice for correcting a deficiency.
L-threonate
Best for Cognition (investigational)
Marketed for brain penetration on the basis of animal data. Human evidence is preliminary and the cost per dose is high.
Malate
Best for Fatigue, muscle soreness
Well tolerated. The claimed advantage for fatigue rests on the malate moiety rather than on trial data.
Food & Timing
Take with food to reduce gastrointestinal upset. Split doses above 350 mg across the day — absorption falls as the single dose rises, and loose stools become more likely.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.