Magnesium is important for normal electrical activity of the heart. A significant magnesium deficiency can contribute to abnormal rhythms, but taking magnesium supplements is not a universal treatment for unexplained heart palpitations.
Low magnesium can contribute to abnormal heart rhythms and may be one possible cause of palpitations, particularly when deficiency is substantial or occurs together with low potassium or calcium. Correcting a confirmed magnesium deficiency is important. However, magnesium supplements have not been proven to treat every type of palpitation, PVC, PAC or atrial fibrillation. If palpitations keep returning, the priority is to identify the rhythm and check for relevant causes rather than automatically taking magnesium.
Do Not Treat Unexplained Palpitations With High-Dose Magnesium on Your Own
Magnesium supplements are readily available, but more is not necessarily better.
Excess magnesium can become dangerous, particularly when kidney function is impaired because the kidneys are responsible for removing excess magnesium.
Severe magnesium excess can cause:
- marked weakness;
- low blood pressure;
- reduced reflexes;
- slow or abnormal cardiac conduction;
- respiratory depression; and
- cardiac arrest in extreme toxicity.
If you have kidney disease, heart-conduction disease or take multiple prescription medicines, discuss magnesium supplements with a healthcare professional before using them specifically for palpitations.
What Does Magnesium Do in the Heart?
Magnesium is an essential mineral and electrolyte involved in hundreds of biochemical reactions throughout the body.
It contributes to:
- energy production;
- nerve signaling;
- muscle contraction and relaxation;
- movement of potassium and calcium across cell membranes; and
- normal electrical function of cardiac muscle.
These functions help explain why a severe disturbance in magnesium concentration can affect the heart’s electrical stability.
Being biologically important for cardiac electrical activity does not mean that taking additional magnesium will correct every palpitation or arrhythmia. Whether replacement helps depends strongly on magnesium status, the rhythm involved and the underlying cause.
Can Low Magnesium Cause Heart Palpitations?
Yes. Significant magnesium deficiency, called hypomagnesemia, can contribute to abnormal heart rhythms.
Early deficiency may cause relatively nonspecific symptoms such as:
- loss of appetite;
- nausea;
- vomiting;
- fatigue; and
- weakness.
With more severe deficiency, symptoms may include:
- numbness or tingling;
- muscle cramps or contractions;
- tremor;
- seizures;
- low potassium;
- low calcium; and
- abnormal heart rhythms.
Low magnesium may be particularly important when another factor already increases arrhythmia risk, such as low potassium or a medication that prolongs the QT interval.
Palpitations Do Not Prove That Your Magnesium Is Low
Palpitations have many possible causes, including premature beats, atrial fibrillation, SVT, anxiety, caffeine, thyroid disease, anemia, medication effects and other electrolyte abnormalities.
Magnesium deficiency is one possible cause, not a diagnosis that can be made simply because the heartbeat feels irregular.
See our broader guide to causes of heart palpitations .
Why Can Magnesium Levels Become Low?
True magnesium deficiency is uncommon from low dietary intake alone in otherwise healthy people because the kidneys conserve magnesium when body stores are falling.
Deficiency becomes more likely when magnesium is being lost or absorbed poorly.
Chronic diarrhea or malabsorption
Gastrointestinal disorders such as inflammatory bowel disease, celiac disease or other causes of malabsorption can reduce magnesium absorption or increase losses.
Alcohol use disorder
Long-term heavy alcohol use can contribute to poor dietary intake, gastrointestinal losses and increased urinary magnesium loss.
Diabetes
Poorly controlled diabetes with excessive urination can increase urinary losses of magnesium.
Diuretic medicines
Loop and thiazide diuretics can increase urinary magnesium loss. The effect differs from potassium-sparing diuretics.
Long-term proton pump inhibitors
Prescription PPIs such as omeprazole, esomeprazole and lansoprazole can rarely cause significant hypomagnesemia during prolonged treatment.
Other medicines or illness
Certain antibiotics, chemotherapy medicines, kidney-tubule disorders, pancreatitis and other medical conditions can also alter magnesium status.
PPIs, Low Magnesium and Palpitations
Proton pump inhibitors are widely used to treat GERD, ulcers and other acid-related disorders.
Long-term prescription PPI use can rarely lead to hypomagnesemia. FDA labeling has reported cases after at least three months of treatment, although most occurred after about a year or longer.
Serious manifestations can include:
- muscle spasms;
- tremor;
- seizures;
- palpitations; and
- cardiac arrhythmias.
In some reported cases, magnesium replacement alone corrected the deficiency. In others, the PPI also had to be discontinued.
The appropriate approach is to discuss the symptoms, treatment duration, other medications and whether magnesium testing is appropriate with your healthcare professional. The clinician can then decide whether the medicine should be continued, adjusted or changed.
See our related guide to GERD and heart palpitations .
How Is Magnesium Deficiency Tested?
A blood magnesium test is the most commonly available way to check magnesium concentration.
However, interpreting magnesium status is not always straightforward.
Most magnesium is stored inside cells and in bone, while less than 1% circulates in serum. As a result, a serum magnesium result does not perfectly represent all magnesium stored in the body.
Clinicians therefore interpret the result together with:
- symptoms;
- medical history;
- kidney function;
- medications;
- gastrointestinal losses;
- potassium and calcium levels; and
- ECG findings when a rhythm problem is suspected.
Even when magnesium is low, an ECG can help identify the actual rhythm. If symptoms come and go, a Holter, patch or event monitor may be needed because a brief resting ECG can miss intermittent premature beats or arrhythmias.
Learn more about recurrent symptoms in our constant and frequent heart palpitations guide.
Do Magnesium Supplements Help Heart Palpitations?
They can be useful when a person has a genuine magnesium deficiency or another specific clinical indication.
Evidence for routine supplementation in people with unexplained palpitations and normal magnesium status is much weaker.
Premature beats
A small randomized trial in symptomatic patients with frequent premature ventricular or supraventricular complexes found that magnesium pidolate reduced premature-complex frequency and symptoms.
However, follow-up showed that some patients relapsed, and the investigators emphasized that magnesium was not a definitive or curative treatment.
Premature atrial contractions
Another randomized pilot study using oral magnesium oxide successfully increased circulating magnesium but did not significantly reduce premature atrial-contraction burden compared with placebo.
What This Evidence Means for Patients
There is enough evidence to support correcting magnesium deficiency and to justify ongoing research into magnesium and arrhythmias.
There is not enough evidence to say that everyone with PVCs, PACs, atrial fibrillation or unexplained palpitations should take magnesium supplements.
How much magnesium do adults normally need?
The recommended total dietary intake for most adults ranges from about 310 to 420 mg per day, depending on age and sex. This includes magnesium obtained from food, beverages and supplements.
For healthy adults, the U.S. tolerable upper intake level for magnesium specifically from supplements and medications is 350 mg per day unless a healthcare professional recommends a different amount.
This 350 mg limit does not include magnesium naturally present in food.
Clinicians may use doses outside general dietary limits when treating documented deficiency or another medical indication. Those situations should not be converted into an internet dosing recommendation for unexplained palpitations.
What Are Good Food Sources of Magnesium?
For most people, food is the preferred way to meet routine magnesium needs.
Useful sources include:
- pumpkin and other seeds;
- almonds, cashews and other nuts;
- spinach and other leafy green vegetables;
- black beans and other legumes;
- whole grains;
- soy foods;
- avocado;
- some fortified cereals; and
- milk and yogurt.
Magnesium naturally present in food is not subject to the supplemental magnesium upper limit because healthy kidneys normally regulate excess magnesium obtained through a usual diet.
When Is Intravenous Magnesium Used for Heart Rhythm Problems?
IV magnesium has important medical uses, but it is not given for every arrhythmia.
Torsades de Pointes
One established emergency cardiac use is recurrent torsades de pointes, a form of polymorphic ventricular tachycardia associated with a prolonged QT interval.
Current American Heart Association guidance states that magnesium may be considered for recurrent polymorphic VT associated with long QT. Routine magnesium is not recommended for polymorphic VT when the QT interval is normal.
Severe hypomagnesemia
Intravenous magnesium may also be used when magnesium deficiency is severe, symptomatic, associated with serious arrhythmia or cannot be corrected adequately by the oral route.
This is clinician-directed therapy that requires assessment of kidney function, electrolytes and the cardiac rhythm.
Important Correction: IV Magnesium Is Not for “All Refractory Arrhythmias”
The older version of this page stated that IV magnesium should be considered for essentially all refractory arrhythmias even when the magnesium level is normal.
That is no longer appropriate. Modern resuscitation guidance has specific indications. Magnesium is particularly relevant to torsades de pointes with prolonged QT and to clinically important magnesium deficiency, rather than being a universal rescue drug for every abnormal rhythm.
Can Too Much Magnesium Cause Heart Problems?
Yes, although clinically important hypermagnesemia is uncommon in people with normal kidney function.
The greatest risk occurs when kidney function is significantly reduced and magnesium accumulates from supplements, antacids, laxatives or medical treatment.
Significant magnesium excess may cause:
- nausea or weakness;
- reduced reflexes;
- low blood pressure;
- drowsiness or confusion;
- slow breathing;
- sinus bradycardia;
- prolongation of cardiac conduction;
- AV block; and
- cardiac arrest in extreme toxicity.
Kidney Disease Requires Extra Caution
The kidneys normally eliminate excess magnesium. When kidney function is substantially impaired, magnesium-containing supplements, laxatives or antacids can accumulate.
People with chronic kidney disease should discuss supplemental magnesium with their healthcare professional rather than assuming that an over-the-counter product is automatically safe.
Magnesium and Digoxin: An Important Correction
The previous version of this article stated that magnesium increases digoxin toxicity and that people taking digitalis should not use magnesium.
That is inaccurate.
In fact, low magnesium can increase susceptibility to digoxin toxicity. Current digoxin prescribing information advises maintaining normal potassium and magnesium concentrations because depletion of either electrolyte can sensitize the heart to digoxin.
This does not mean someone taking digoxin should independently start high-dose magnesium.
Digoxin has a narrow therapeutic range, and kidney function, potassium, magnesium and other medicines can all affect safety. Supplement decisions should therefore be coordinated with the clinician managing the treatment.
Can Magnesium Supplements Interact With Medicines?
Yes. Magnesium supplements can affect absorption of some medicines.
Examples include:
- tetracycline antibiotics such as doxycycline;
- quinolone antibiotics such as ciprofloxacin and levofloxacin; and
- oral bisphosphonates such as alendronate.
Some medicines can also alter magnesium levels. Loop and thiazide diuretics may increase magnesium loss, while long-term PPI therapy can contribute to hypomagnesemia in selected patients.
For this reason, tell your doctor or pharmacist about supplements as well as prescription medicines.
Dr. Albana’s Note
When someone with palpitations asks me whether they should take magnesium, I first look for a reason to suspect deficiency: prolonged diarrhea, vomiting, diuretic use, long-term PPI treatment, heavy alcohol use, poor nutrition or another condition that can affect electrolytes. I also want to know what rhythm is causing the palpitation. Correcting a documented deficiency is important, but taking magnesium without identifying the rhythm can delay the diagnosis of PVCs, atrial fibrillation, thyroid disease or another cause.
When Should You See a Doctor?
Arrange medical assessment if:
- palpitations keep returning or are becoming more frequent;
- your heartbeat is persistently fast or irregular;
- you have prolonged diarrhea or repeated vomiting;
- you take a diuretic or long-term proton pump inhibitor;
- you take digoxin or a QT-prolonging antiarrhythmic medicine;
- you have kidney disease;
- you have muscle cramps, tremor, weakness or numbness together with palpitations;
- you have known low potassium or calcium;
- symptoms started after beginning a supplement; or
- you are taking large amounts of magnesium-containing laxatives or antacids.
Urgent Warning Signs
Seek urgent or emergency medical care if palpitations occur with:
- significant chest pain or pressure;
- fainting or loss of consciousness;
- collapse;
- severe shortness of breath;
- severe dizziness or near-fainting;
- a sustained very rapid or markedly irregular heartbeat;
- seizures;
- severe weakness;
- markedly slowed breathing;
- confusion or profound drowsiness after taking magnesium; or
- rapidly worsening symptoms.
See our chest pain and heart palpitations guide for additional information, but emergency symptoms require medical care first.
Most Asked Questions
Can low magnesium cause heart palpitations?
Yes. Significant hypomagnesemia can cause abnormal heart rhythms, particularly when it occurs with low potassium, low calcium or other arrhythmia risk factors. Palpitations alone, however, do not prove magnesium deficiency.
Will taking magnesium stop my palpitations?
Not necessarily. Magnesium replacement may help when a deficiency is contributing to the rhythm problem. Evidence for routine supplementation in people with unexplained palpitations and normal magnesium levels is limited.
Does magnesium help PVCs?
A small randomized study found fewer symptomatic premature ventricular and supraventricular complexes with one form of oral magnesium, but symptoms later recurred in some patients and the treatment was not considered curative. PVCs should be evaluated according to their frequency, symptoms and cardiac context rather than treated automatically with magnesium.
Does magnesium help atrial fibrillation?
Low magnesium may increase electrical instability, and magnesium correction is important when deficiency is present. IV magnesium has also been studied as an adjunct in selected acute AF situations. However, oral magnesium supplementation is not a standard replacement for evidence-based AF treatment.
What magnesium level is considered low?
Reference ranges vary between laboratories. Serum magnesium is commonly used for testing, but it represents only a small fraction of total body magnesium. Your clinician should interpret the laboratory result together with symptoms, kidney function, other electrolytes and medications.
How much magnesium do adults need each day?
Recommended total intake is generally about 310 to 420 mg daily for adults, depending on age and sex. This amount includes magnesium from food and other sources. The U.S. upper limit of 350 mg per day applies specifically to supplemental or medication-derived magnesium for healthy adults, not magnesium naturally present in food.
Can too much magnesium cause a slow heartbeat?
Severe hypermagnesemia can slow cardiac conduction and may cause bradycardia, AV block, hypotension and, at extreme levels, cardiac arrest. Clinically important excess is uncommon when kidney function is normal but becomes much more likely with significant kidney failure.
Can omeprazole or another PPI cause low magnesium?
Yes, rarely. Long-term prescription PPI treatment can cause significant hypomagnesemia, most often after prolonged use. Do not automatically stop the medicine; discuss symptoms and whether magnesium testing is appropriate with the clinician managing your treatment.
Can I take magnesium if I use digoxin?
Do not assume magnesium is forbidden with digoxin. Low magnesium can actually increase susceptibility to digoxin toxicity. However, digoxin requires careful management, so magnesium supplements and electrolyte abnormalities should be discussed with the treating clinician.
When is IV magnesium used for an arrhythmia?
A major established emergency use is recurrent torsades de pointes, a polymorphic ventricular tachycardia associated with prolonged QT. IV magnesium may also be used for severe symptomatic magnesium deficiency. It is not routinely recommended for every arrhythmia.
Related Heart Palpitation Guides
Medical References
- National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals. Updated 2025. NIH Office of Dietary Supplements .
- American Heart Association. 2025 Guidelines for CPR and Emergency Cardiovascular Care: Adult Advanced Life Support — Polymorphic Ventricular Tachycardia. American Heart Association .
- Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation. Circulation. 2024.
- U.S. Food and Drug Administration. Proton Pump Inhibitor Labeling: Hypomagnesemia Warning. FDA.
- DailyMed. Digoxin — Full Prescribing Information: Use in Patients With Electrolyte Disorders. U.S. National Library of Medicine. DailyMed .
- MedlinePlus. Magnesium Blood Test. U.S. National Library of Medicine. MedlinePlus .
- De Falco CNML, Grupi C, Sosa E, et al. Successful Improvement of Frequency and Symptoms of Premature Complexes After Oral Magnesium Administration. Arquivos Brasileiros de Cardiologia. 2012;98(6):480-487. PubMed .
- De Falco CNML, Darrieux FCC, Grupi C, et al. Late Outcome of a Randomized Study on Oral Magnesium for Premature Complexes. Arquivos Brasileiros de Cardiologia. 2014;103(6):468-475. PubMed .
- Lutsey PL, Chen LY, Eaton A, et al. A Pilot Randomized Trial of Oral Magnesium Supplementation on Supraventricular Arrhythmias. Nutrients. 2018;10(7):884. PubMed .
- Merck Manual Professional Edition. Hypermagnesemia. Reviewed June 2025. Merck Manual .
About the Medical Team
Dr. Albana Greca, MBBS, MMedSc
Family Physician / General Practitioner
Dr. Albana Greca has more than 20 years of experience in primary care, general medicine, chronic disease management, prevention, patient education and digital health.
Dr. Benard Shehu, MBBS, MS
Cardiologist
Dr. Benard Shehu has more than 19 years of cardiovascular experience, including clinical experience relevant to arrhythmias and cardiovascular disease.