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Magnesium

Related Terms

  • Chelated magnesium, Emgesan®, Epsom salts, magnesia, magnesium aluminum sulfite, magnesium aspartate, magnesium carbonate, magnesium chloride, magnesium citrate, magnesium diglycine, magnesium disuccinate hydrate, magnesium gluconate, magnesium glycerophosphate, magnesium glycinate, magnesium hydroxide, magnesium lactate, magnesium malate, magnesium murakab, magnesium orotate, magnesium oxide, magnesium phosphate, magnesium pidolate, magnesium salicylate, magnesium sulfate, magnesium sulphate, magnesium trisilicate, milk of magnesia, Slo-Mag®, Super Malic®.

Background

  • The human body contains large amounts of the element magnesium. Magnesium is involved in more than 300 chemical reactions. The first reported medicinal use of magnesium occurred in the 17th Century, after a farmer found that well water, which contained magnesium sulfate, had soothing and healing properties when applied to the skin. Since then, Epsom salts, which contain magnesium sulfate, have been commonly applied to the skin and added to baths. Magnesium salts in various forms have been used for centuries as laxatives.
  • Magnesium sulfate has a long history of use for the treatment of pre-eclampsia (high blood pressure and excess protein in the urine) and eclampsia (a toxic condition that can lead to seizures) in pregnant women.
  • Studies on magnesium have shown it to be effective for the treatment of acute childhood asthma. Some studies have also shown benefit from magnesium for the treatment of several heart disorders, chronic obstructive pulmonary disease (COPD), type 2 diabetes, hearing loss, leg cramps during pregnancy, and side effects from the drug succinylcholine (a neuromuscular blocker). At higher doses, magnesium may control high blood pressure, although study findings are unclear.

Evidence Table

    Disclaimer

    These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

    A Pre-eclampsia (and eclampsia)

    Pre-eclampsia (high blood pressure and excess protein in the urine) and eclampsia (a toxic condition during pregnancy that can cause seizures) are common problems of pregnancy that can lead to serious complications and death. Healthcare professionals commonly inject magnesium sulfate into the veins in cases of pre-eclampsia and eclampsia. Magnesium sulfate is considered a superior drug for the prevention of the recurrence of seizures in eclampsia and for seizure prevention in pre-eclampsia. A common, but not serious, side effect of magnesium sulfate therapy is flushing (reddened skin, especially on the neck and cheeks).

    B Arrhythmia (irregular heartbeat)

    Irregular heartbeats are the most common complications after heart surgery. Magnesium injected into the vein has been reported to reduce irregular heartbeats (e.g., atrial fibrillation and cardiac arrhythmias). However, it was not found to affect the length of hospital stay, the incidence of heart attack, or death.

    B Asthma

    Asthma can frequently worsen and range from mild to severe attacks. The use of magnesium sulfate is one of many treatment options available during acute asthma attacks. Magnesium sulfate administered in the vein, or with a nebulizer combined with other asthma therapies, has been shown to be effective for the treatment of acute asthma attacks, particularly in children with severe symptoms. However, magnesium is not as effective for mild-to-moderate attacks.

    B Diabetes (type 2)

    Type 2 diabetes is often preventable through diet and exercise, as obesity is a major factor in its development. Magnesium taken by mouth has been reported to reduce the risk of developing type 2 diabetes and to improve blood sugar control in type 2 diabetic patients. Other than a modest decrease in blood pressure, magnesium supplementation was found to have only a small impact on other important endpoints associated with diabetes complications.

    B Hearing loss

    The benefits of magnesium taken by mouth have been investigated in cases of hearing loss caused by noise or an unknown cause. Magnesium treatment has been shown to reduce temporary and permanent hearing loss caused by noise. To date, it is not clear how magnesium benefits hearing loss.

    B Neuroprotection (for premature infants)

    Premature delivery may result in many adverse effects in infants, including blindness, deafness, cerebral palsy, and other major disabilities. A systematic review suggests that magnesium sulfate during pregnancy may improve motor function in early childhood for infants born prematurely and may reduce the risk of development of cerebral palsy.

    C Acute myocardial infarction (heart attack)

    Magnesium injected into the veins has been reported to reduce arrhythmia (irregular heartbeat), which commonly occurs during a heart attack. It is unclear whether magnesium therapy injected into the vein reduces the number of deaths caused by heart attacks. Magnesium is an alternative therapy for patients who are not able to take traditional therapies for the treatment of a heart attack.

    C Alcohol withdrawal

    Intramuscular administration of magnesium as a supplement to benzodiazepines showed no significant difference in the severity of withdrawal symptoms. Additional high-quality clinical research is needed in this area.

    C Cardiac arrest (loss of heart function)

    Cardiac arrest is a life-threatening event in which the heart stops contracting properly. Because of an apparent benefit of magnesium for heart attack, it has been used together with other agents for cardiopulmonary resuscitation (CPR). However, it is unclear whether magnesium is the ideal treatment choice for CPR, due to conflicting scientific study findings. Additional high-quality clinical research is needed in this area.

    C Chronic obstructive pulmonary disease (COPD)

    Chronic obstructive pulmonary disease (COPD) is a progressive lung disease in which the airways become narrowed. The greatest risk factor for COPD is smoking. Acute attacks of COPD are commonly seen and difficult to treat. Administration of magnesium sulfate into the vein after beta-agonists (drugs that help with breathing) was found to be safe and modestly effective in the treatment of acute flare-ups of COPD. This combination was more effective than beta-agonist therapy alone. More high-quality clinical research is necessary to draw a conclusion.

    C Coronary artery disease (heart disease)

    Experimental evidence has suggested that magnesium may play a beneficial role in regulating the formation of blood clots. A clinical study showed that taking magnesium by mouth inhibits formation of blood clots in stable patients with coronary artery disease (heart disease). Additional research is needed in this area.

    C Fibromyalgia

    Fibromyalgia is a disorder that causes chronic widespread pain and a painful response to gentle touch. Other features include marked fatigue, sleep disturbance, and joint stiffness. A small study found that Super Malic® (containing malic acid and magnesium) may be beneficial for this condition. Additional research is needed to confirm early findings.

    C Hemorrhage

    Magnesium infusion reduced the risk of poor outcome and delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage. Additional research is needed to confirm available research results.

    C High blood pressure

    It is unclear whether oral magnesium supplementation can lower blood pressure in patients with mild-to-moderate high blood pressure or prevent the onset of high blood pressure. Higher doses of magnesium are associated with a decrease in blood pressure to very low levels. Several studies have reported a small and not significant decrease in blood pressure with magnesium. Further research is needed on the use of magnesium in the treatment of high blood pressure.

    C Kidney stones

    In an analysis of two studies, there was a lack of benefit from magnesium on recurrent calcium stone formers. Further research is needed on the use of magnesium in the treatment of kidney stones.

    C Leg cramps (during pregnancy)

    Leg cramps are a common problem during pregnancy, and pregnant women often have low blood levels of magnesium. Therefore, it has been suggested that raising magnesium levels may decrease leg cramps during pregnancy. Magnesium taken by mouth has been reported to reduce pregnancy-related leg cramps. Additional research is needed in this area.

    C Migraine headache

    Migraine headaches can be extremely painful and are often accompanied by nausea. More women suffer from migraine headaches than men. Furthermore, migraine headaches in women can be related to the menstrual cycle. Magnesium has been evaluated for use in migraines. Human studies have found that magnesium sulfate may reduce the intensity of migraine headaches. Low magnesium levels may increase menstrual-related migraines in susceptible women. Additional research is needed to confirm these results.

    C Mitral valve prolapse (valvular heart disease)

    Mitral valve prolapse (MVP) syndrome is a common disorder characterized by a variety of complaints that affect quality of life. Low magnesium levels and an excess of the catecholamine adrenaline have been suggested as contributing factors in causing MVP. Many patients with heavily symptomatic mitral valve prolapse have low magnesium levels in the blood. Magnesium supplementation has been reported to improve most mitral valve prolapse. Additional research is needed to reach a conclusion.

    C Muscle spasms

    Magnesium may help prevent involuntary muscle twitching caused by the drug succinylcholine (a neuromuscular blocker). Involuntary muscle twitching is an adverse effect of patients undergoing general anesthesia. Additional high-quality research is needed to confirm these results.

    C Myocardial infarction prevention (heart attack prevention)

    Magnesium has been used in the treatment of heart attack. Therefore, oral magnesium therapy has been considered a preventive therapy in patients who have survived acute heart attacks. A human study did not show benefit of oral magnesium therapy for prevention in these individuals. The study also suggested that the risk of heart problems might have been increased by this therapy. Additional research is needed in this area.

    C Pregnancy nutritional supplement

    Many women have low magnesium levels in the body. Magnesium supplementation has been given during pregnancy as a nutritional supplement. Currently, there is not enough evidence to support magnesium supplementation during pregnancy as a means to improve the health of the mother or infant. Additional research is needed in this area.

    C Pregnancy-related complications

    Magnesium supplementation has been given during pregnancy in order to reduce pregnancy complications. Currently, there is not enough evidence to support magnesium supplementation during pregnancy to reduce pregnancy-related complications. Additional research is needed in this area.

    C Premenstrual syndrome (PMS)

    Premenstrual syndrome encompasses many physical, psychological, and emotional symptoms related to the menstrual cycle. Symptoms usually appear two weeks before the onset of the menstrual cycle and in some cases significantly affect a woman’s daily routine during that time. Oral magnesium has been reported to benefit mood changes associated with premenstrual syndrome (PMS). Additional research is needed in this area.

    C Shivering (postoperative)

    There is a lack of evidence for the use of magnesium for postoperative shivering. Additional research is needed in this area.

    C Traumatic brain injury

    There is not enough evidence to support the use of magnesium salts in patients with acute traumatic brain injuries. Magnesium has also been studied for brain hemorrhage in combination with other agents; however, the results are unclear.

    D Athletic performance

    Magnesium is involved in many reactions in the body. Low magnesium levels may affect exercise performance. Some experts suspect that magnesium levels may not be adequate in many people, especially athletes. Many female athletes do not get enough magnesium from the diet, and magnesium is also lost in the urine with exercise. To date, there is not enough evidence that taking magnesium can improve athletic performance. However, it may reduce the stress response to exercise.

    D Pre-term labor contractions

    Magnesium has been used for tocolysis (prevention of preterm labor contractions). Available studies have not demonstrated that magnesium is effective for this use. Additionally, it is possible that the use of magnesium for contractions may cause the death of the fetus.

*Key to grades:

Tradition

    Disclaimer

    The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Dosing

    Disclaimer

    The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

  • Adults (18 years and older)

    • The daily magnesium requirement for healthy adults has not been clearly established. The recommended dietary allowances for magnesium by mouth are 400 milligrams (for males aged 19-30), 310 milligrams (for females aged 19-30), 420 milligrams (for males aged over 30), and 320 milligrams (for females aged over 30). Magnesium has been given in doses of 600-1,200 milligrams by mouth daily for months without major adverse effects.
    • The following doses by mouth have been used without scientific evidence of improvement in athletic performance: 17 millimoles of magnesium orotate taken twice daily for four weeks; 500 milligrams of magnesium oxide taken daily for three weeks; and 100 milligrams of elemental magnesium taken daily for one month. In other studies, doses of magnesium have ranged from 116 to 500 milligrams daily, for one day to three months.
    • For the treatment of hearing loss, 167 milligrams of magnesium aspartate has been taken by mouth daily for eight weeks.
    • For the treatment of high blood pressure, 10-40 millimoles of magnesium has been taken by mouth daily for 3-24 weeks, with no significant benefit observed.
    • For the treatment of leg cramps (during pregnancy), five millimoles of elemental magnesium has been taken by mouth daily for three weeks.
    • For the treatment of migraine headaches, 360 milligrams of elemental magnesium has been taken by mouth three times daily for two months.
    • For the treatment of mitral valve prolapse, 1,200-1,800 milligrams of magnesium carbonate has been taken by mouth daily for five weeks. For heart attack prevention, 15 millimoles of magnesium hydroxide has been taken daily for one year.
    • For the treatment of premenstrual syndrome (PMS), 360 milligrams of magnesium pyrrolidone carboxylic acid has been taken by mouth daily for two weeks (for two months in duration).
    • Magnesium sulfate is available as a gel containing magnesium chloride that can be applied to the skin. Magnesium sulfate paste is used for the treatment of boils, carbuncles, and abscesses. Epsom salts (magnesium sulfate) are added to bath water as a soothing agent for a variety of skin conditions.
    • For the treatment of a heart attack, 1.92-12 grams of magnesium has been given intravenously for 20-72 hours.
    • For the treatment of arrhythmias (irregular heartbeats), 1.2-10 grams total of magnesium sulfate has been given intravenously over periods ranging from five minutes to 24 hours.
    • For the treatment of asthma, a range of intravenous doses have been used: 10-25 milligrams of magnesium sulfate per kilogram infused into the vein over 20 minutes; two grams of magnesium injected into the vein along with beta-2 agonist and steroid therapy for 30 minutes; a loading dose of two grams of magnesium sulfate injected into the vein over 20 minutes, followed by two grams per hour over four hours plus standardized aminophylline (a drug that helps with breathing) and steroid therapy; two grams of magnesium sulfate diluted in 50 milliliters of 5% dextrose in water (D5W) infused over 20 minutes into the vein, plus a steroid.
    • For the treatment of pre-eclampsia or eclampsia, magnesium sulfate is injected into the vein, starting with a four-gram dose followed by 1-3 grams per hour. Dosage and duration of magnesium for preterm labor contractions is similar to those for pre-eclampsia and eclampsia.
  • Children (under 18 years old)

    • The recommended dietary allowances for magnesium by mouth are 80 milligrams (for ages 1-3), 130 milligrams (for ages 4-8), 240 milligrams (for ages 9-13), 410 milligrams (for males aged 14-18), and 360 milligrams (for females aged 14-18). Adequate intakes for infants are 30 milligrams (for those 0-6 months old) and 75 milligrams (for those 7-12 months old).
    • The safe maximum daily intake for infants has not been determined. The following doses by mouth of elemental magnesium have been used: 65 milligrams daily for children 1-3 years of age; 110 milligrams daily for children 4-8 years of age; 350 milligrams daily for children aged nine years or older.
    • For the treatment of asthma, the following intravenous doses have been used: 0.2 milliliters of 50% magnesium sulfate per kilogram infused into the vein over 35 minutes, plus oxygen, the beta-2 agonist salbutamol (through a nebulizer), and the bronchodilator aminophylline (depending on the patient’s response to the experimental treatment); magnesium sulfate (25 milligram per kilogram, up to two grams total in 100 milliliters of normal saline solution) plus methylprednisolone infused into the vein (two milligrams per kilogram, up to 100 milligrams total) given prior to receiving magnesium.

Safety

    Disclaimer

    The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

  • Allergies

    • Avoid in patients with known allergy to magnesium or other products found in magnesium supplements. Magnesium allergy is reported to be extremely rare.
  • Side Effects and Warnings

    • Magnesium may cause stomach irritation, nausea, vomiting, diarrhea, decreased skeletal muscle tone and muscular reflex, headache, and decreased estrogen levels.
    • Magnesium injected into the vein may cause low blood pressure, slow heart rate, fast heart rate, skin flushing (red face), excessive sweating, eruption of itching welts on the skin, problems at the injection site, and respiratory depression (breathing problems).
    • Magnesium sulfate applied to the skin for prolonged periods of time or repeatedly may cause skin damage.
    • High blood levels of magnesium (called hypermagnesemia) may cause thirst; drowsiness; low blood pressure; delirium; coma; disorders of the heart, muscle, and respiratory systems; and death. Toxic levels of magnesium can cause depression of the central nervous system.
    • Use cautiously in patients with diabetes, blood pressure disorders, bleeding disorders, or decreased skeletal muscle tone, or in patients taking antidiabetic agents, blood pressure-lowering agents, anticoagulants, antiplatelet agents, or antibiotics such as fluoroquinolones and cephalosporins.
    • Avoid in patients with kidney disorders or atrioventricular heart block.
    • Avoid as a laxative in patients with stomach disorders.
    • Avoid intravenous magnesium in women with toxemia during the first few hours of labor.
    • Avoid high intravenous doses in pregnant women for eclampsia, pre-eclampsia, or tocolysis (labor prevention).
    • Avoid in patients with known allergy to magnesium or other products found in magnesium supplements, although magnesium allergy is reported to be extremely rare.
  • Pregnancy and Breastfeeding

    • There appear not to be many side effects associated with therapeutic doses of magnesium in infants of women who are pregnant or breastfeeding. According to the National Institute of Health’s Lactation and Toxicology Database (LactMed), magnesium sulfate and magnesium hydroxide are acceptable to use during breastfeeding. However, there was one report of delayed full milk production with three days of use of magnesium sulfate for pregnancy-induced hypertension.
    • Avoid intravenous magnesium in women with toxemia during the first few hours of labor. Avoid high intravenous doses in pregnant women for eclampsia, pre-eclampsia, or tocolysis (labor prevention).

Interactions

    Disclaimer

    Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

  • Interactions with Drugs

    • Magnesium may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or in those taking drugs that may increase the risk of bleeding.
    • Magnesium may cause low blood pressure. Caution is advised in patients taking medications that lower blood pressure.
    • Magnesium taken with other diabetes medications (such as sulfonylureas) may cause low blood sugar levels. Caution is advised in patients taking drugs for the treatment of diabetes.
    • Magnesium may decrease serum estrogen levels. Use caution with estrogens, oral contraceptives, and hormone replacement therapy.
    • Magnesium may also interact with ACE inhibitors, amphotericin-B, analgesics, antiarrhythmia agents, antiasthma drugs, antibiotics (aminoglycosides, fluoroquinolones, cephalosporins, tetracyclines, quinolones, sulfonylureas), anticancer drugs (amifostine, carboplatin, cisplatin, aldesleukin, cetuximab (Erbitux®), amifostine, panitumumab (Vectibix®)), antiseizure drugs, beta-agonists, bisphosphonates, calcium channel blockers, calcium salts, cardiac glycosides (digoxin), cholestyramine (Questran®), CNS depressants, corticosteroids, diuretics, drugs used for osteoporosis, foscarnet (Foscavir®), labetalol, levomethadyl, neuromuscular blockers, neuroprotective agents, nonsteroidal anti-inflammatory drugs (NSAIDs), pentamidine (NebuPent®, Pentacarinat®, Pentam 300®), phosphates, proton pump inhibitors (PPIs), quinidine, skeletal muscle relaxants, tacrolimus (FK506, Prograf®), and thyroid hormones.
  • Interactions with Herbs and Dietary Supplements

    • Magnesium may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or in those taking herbs or supplements that may increase the risk of bleeding.
    • Magnesium may cause low blood pressure. Caution is advised in patients taking herbs or supplements that lower blood pressure.
    • Magnesium taken with other herbs and supplements that lower blood sugar may cause low blood sugar levels. Caution is advised in patients taking herbs or supplements for the treatment of diabetes.
    • Magnesium may decrease serum estrogen levels. Use caution with phytoestrogens or other hormonal herbs or supplements.
    • Magnesium may also interact with ACE inhibitors, aluminum, analgesics, antiarrhythmics, antiasthmatic agents, antibacterials, anti-inflammatory agents, antiseizure agents, bronchodilators, calcium, calcium channel blockers, cardiac glycosides, dairy products, diuretics, herbs and supplements that decrease calcium, herbs and supplements used for osteoporosis, muscle relaxants, neuromuscular blockers, neuroprotective agents, oleander, phosphates, proton pump inhibitors (PPIs), quinidine herbs and supplements, sedatives, steroids, and thyroid agents.

Attribution

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration ().

Bibliography

    Disclaimer

    Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to . Selected references are listed below.

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