Supplements for heart palpitations: what may help, what can cause them, and when to worry

Short answer

No supplement is proven to treat heart palpitations in people with normal blood tests. What supplements can do is fix a deficiency that causes them, or, more often, be the cause. The deficiencies most linked to palpitations are iron-deficiency anaemia, which makes the heart beat faster to deliver oxygen, and low potassium or magnesium, which can trigger irregular rhythms (1, 2). An overactive thyroid is another common medical cause.

On the other side, a surprising number of products cause palpitations: caffeine and energy drinks, pre-workout powders, weight-loss products containing bitter orange (synephrine) or undeclared stimulants, "thyroid support" products, and liquorice root (3). High-dose fish oil has been linked to a higher risk of atrial fibrillation (4).

Magnesium for heart palpitations is widely recommended online. Magnesium is used in hospital for some rhythm problems, and correcting a low level can help. Without a deficiency, there is little good evidence that magnesium tablets stop palpitations.

If your heart pounds when you are anxious, lie down or after coffee, you are not imagining it, and it is not a sign that you are "overreacting". Palpitations are common, usually harmless, and still worth understanding.

Note: this article is for general education and is not medical advice. Call 911 if palpitations come with chest pain, shortness of breath, dizziness or light-headedness, unusual sweating or fainting, or if they do not go away. Do not take potassium or high-dose magnesium without a blood test and medical advice.

What palpitations are and why they happen

Palpitations are the feeling of your heart beating: pounding, racing, fluttering, thumping or "skipping a beat". They can last seconds or minutes. Most are caused by normal heartbeats that you suddenly notice, or by harmless extra beats called ectopic beats.

The NHS lists the common causes as (1):

• strenuous exercise, lack of sleep, stress or anxiety;

• some medicines;

• alcohol, caffeine, nicotine or recreational drugs;

• menopause or pregnancy;

• medical conditions such as iron-deficiency anaemia, an overactive thyroid, an arrhythmia or heart valve disease.

Our guide to heart arrhythmia and palpitations explains the different rhythm types in more detail, and heart palpitations after eating covers that specific pattern.

Vitamin and mineral deficiencies that can cause palpitations

Vitamin deficiency heart palpitations usually come with other signs: tiredness, breathlessness, pale skin and cold hands with iron or B12 deficiency; muscle weakness, cramps or spasms with potassium and magnesium deficiency. Low potassium and magnesium are most often caused by diuretics, vomiting or diarrhoea, long-term acid-reducing medicines (for magnesium) or heavy alcohol use, rather than diet alone (2, 5).

Can vitamin D deficiency cause heart palpitations? Vitamin D deficiency is not a recognised direct cause of palpitations. Very low vitamin D can lower calcium, which in severe cases affects heart rhythm, but this is rare. Low vitamin D is more often a marker of spending little time outdoors than a cause of a racing heart.

Can magnesium help heart palpitations?

Magnesium for heart palpitations is one of the most common self-help suggestions. Here is what is known:

• In hospital, intravenous magnesium is used for some specific rhythm problems and to prevent atrial fibrillation after heart surgery. That is a different situation from taking tablets at home.

• If your magnesium is low, correcting it can reduce rhythm disturbances, which is why doctors check magnesium in people with palpitations who take diuretics or PPIs (2).

• If your magnesium is normal, there is little good evidence that magnesium supplements reduce palpitations or ectopic beats. Some doctors suggest a trial for troublesome but harmless ectopic beats; within the NIH upper limit of 350 mg a day from supplements it is usually well tolerated, except with kidney disease, where it can build up (2).

If you try it, keep supplement magnesium at or below 350 mg a day, avoid it with kidney disease, and tell your doctor if you take heart medicines. Magnesium does not replace an assessment of palpitations.

Magnesium for heart rate is sometimes searched by people hoping to lower a fast resting pulse. Magnesium does not reliably lower heart rate in healthy people. A consistently fast resting heart rate deserves a doctor's assessment.

Potassium: helpful only when low, risky when not

Potassium is essential for a steady heart rhythm, and low potassium can cause palpitations. But potassium supplements are one of the riskier things to take without a test. Too much potassium can also cause dangerous heart rhythms, especially in people with kidney disease or who take ACE inhibitors, angiotensin receptor blockers or potassium-sparing diuretics such as spironolactone (5).

Potassium-rich foods, such as bananas, potatoes, beans, leafy greens and yoghurt, are a safe way to support normal intake. Supplements should be used only when a blood test shows a need and a doctor recommends them.

Supplements that can cause heart palpitations

This is often the more useful list. If palpitations started recently, check everything you take:

• Caffeine in coffee, energy drinks, pre-workout powders, caffeine tablets, guarana and green tea extract. Our article on caffeine and the wired-and-tired loop shows how caffeine looks in heart rate data.

• Pre-workout products, which often combine high-dose caffeine with other stimulants. A "heart racing" feeling after pre-workout is a common reason people search for this topic.

• Bitter orange (synephrine) in weight-loss and "fat-burner" products. Serious heart events, including abnormal rhythms, have been reported in people taking bitter orange products, usually in combination with other ingredients. An FDA analysis found many products did not contain the labelled amount and some contained undeclared stimulants (3).

• Yohimbine and other stimulant ingredients in sexual health and weight-loss products.

• "Thyroid support" and "metabolism" products, which can contain thyroid hormone or large amounts of iodine and push the thyroid into overdrive.

• Liquorice root (the herbal extract, not most sweets), which can lower potassium and raise blood pressure.

• High-dose fish oil. In a meta-analysis of seven trials with 81,210 people, omega-3 supplements were linked to a higher risk of atrial fibrillation, with the risk greater at doses above 1 g a day (4).

• Ginseng and some other herbal stimulants, which have been linked to palpitations in some people.

If a product is the trigger, palpitations may settle after you stop it; if they do not, see a doctor. If you are unsure, bring the products to your doctor or pharmacist.

Palpitations and anxiety

Anxiety is one of the most common reasons for palpitations, and palpitations themselves can trigger more anxiety, creating a loop. In a panic attack, the heart can race to 120–150 beats a minute, often with breathlessness, tingling and a sense of dread.

Supplements for anxiety, such as magnesium, ashwagandha, L-theanine or lavender, have modest evidence and are covered in our article on anxious at night for no reason and related guides. The approaches that work best for anxiety-related palpitations are slow breathing, reducing caffeine and alcohol, better sleep and, if anxiety is persistent, therapy. Ashwagandha can affect thyroid hormones, so it is worth checking with a doctor if palpitations are part of the picture.

Palpitations in perimenopause and pregnancy

Palpitations are common around menopause. Hormonal shifts can make the heart beat faster or more noticeably, often alongside hot flushes, night sweats and poor sleep (1). Many women look for a supplement at this point. Before adding one, it is worth checking iron (periods can become heavier in perimenopause), thyroid function and caffeine and alcohol intake, which often matter more. If palpitations come with chest pain or breathlessness, or are new and frequent, they still need a proper heart assessment rather than being put down to hormones.

In pregnancy, the heart pumps more blood and beats faster, so palpitations are common and usually harmless. Iron needs rise sharply, and iron-deficiency anaemia is a frequent cause of a racing heart in pregnancy. Do not start herbal products for palpitations in pregnancy without your midwife or doctor's advice.

Supplements and heart medicines

If you already take medicines for your heart, some supplements need extra care:

• Beta-blockers and calcium channel blockers: adding stimulants such as caffeine pills, synephrine or yohimbine works against them; grapefruit affects some calcium channel blockers, such as nifedipine (7).

• Digoxin: St John's wort can weaken its effect (8), and low potassium or magnesium increases the risk of digoxin side effects.

• Antiarrhythmic medicines such as amiodarone: grapefruit can affect them (7), and electrolyte changes from diuretics or laxatives can increase rhythm risks.

• Diuretics, ACE inhibitors, ARBs and spironolactone: these change potassium and magnesium levels, so mineral supplements should only be added after a blood test.

Ask your pharmacist to check every supplement against your heart medicines before you start it, and do not stop or change heart medicines without your doctor.

What helps palpitations right now

During harmless palpitations, these can help:

• Sit or lie down and breathe slowly, with a longer out-breath than in-breath.

• Stop caffeine, nicotine and alcohol for the day.

• Drink some water if you might be dehydrated.

• Notice the trigger: a meal, coffee, a stressful moment, lying on your left side, the days before a period.

If palpitations come with chest pain, shortness of breath, dizziness or light-headedness, unusual sweating or fainting, do not wait to see if they settle: call 911.

Living with palpitations: the questions people ask next

Can low magnesium cause heart palpitations?

Yes, low magnesium can contribute to abnormal heart rhythms, and it often comes with low potassium. It is more likely if you take diuretics or long-term acid-reducing medicines, have diarrhoea or drink heavily. A blood test can check magnesium and potassium, although blood magnesium can look normal when stores are low. Correcting a confirmed deficiency can reduce rhythm problems.

Can iron deficiency cause heart palpitations?

Yes. Iron-deficiency anaemia is one of the medical causes of palpitations listed by the NHS. With less haemoglobin to carry oxygen, the heart beats faster, especially on exertion. Other signs include tiredness, breathlessness, pale skin and hair shedding. A full blood count and ferritin test can confirm it, and palpitations often improve as iron levels recover.

Why does my heart race after taking a supplement?

Many supplements contain stimulants, sometimes without saying so clearly: caffeine, guarana, green tea extract, synephrine (bitter orange), yohimbine or undeclared synthetic stimulants. "Thyroid support" products can contain hormones or high iodine. Stop the product and check the full ingredient list. Call 911 if palpitations come with chest pain, shortness of breath, dizziness or light-headedness, unusual sweating or fainting, or if they do not go away.

Is it safe to take magnesium if I have palpitations?

Ask your doctor first. The NIH upper limit for magnesium from supplements is 350 mg a day for adults, and magnesium can build up to harmful levels with kidney disease. Talk to your doctor if you take heart medicines, because some are affected by changes in potassium and magnesium. Palpitations still need to be assessed, especially if they are new, frequent or come with other symptoms.

Does fish oil cause palpitations?

Fish oil is not a common cause of everyday palpitations, but high doses have been linked to a higher risk of atrial fibrillation, an irregular rhythm that can feel like fluttering or a racing, uneven pulse. The risk appears greater above 1 g a day. If you notice an irregular pulse while taking fish oil, see a doctor.

Can palpitations be a sign of a thyroid problem?

Yes. An overactive thyroid speeds up the heart and can cause palpitations, along with weight loss, heat intolerance, shakiness, anxiety and loose stools. Thyroid supplements, high iodine intake and too high a dose of thyroid medicine can cause the same effect. A TSH blood test checks thyroid function.

Can energy drinks cause palpitations even if I'm young and healthy?

Yes. Energy drinks can contain large amounts of caffeine, sometimes combined with guarana, taurine and sugar, and they are a common reason young, healthy people notice a racing or pounding heart. Drinking several in a short time, mixing them with alcohol, or having them on an empty stomach or before intense exercise raises the chance of palpitations. If you notice your heart racing after energy drinks, cut back or stop, and see a doctor if palpitations continue. Call 911 if they come with chest pain, shortness of breath, dizziness or light-headedness, unusual sweating or fainting.

Before you blame yourself

People with palpitations are often told it is "just anxiety", and then feel embarrassed for worrying. But palpitations are a real physical sensation with real causes, from caffeine and short sleep to anaemia and thyroid problems. Wanting to understand them is reasonable, not hypochondria.

Looking at what came before your palpitations, such as a pre-workout drink, a sleepless night, a new supplement or the days before a period, often reveals a pattern that is easy to change.

When to see a doctor

See a doctor if you have new or different palpitations, if they keep coming back or are becoming more frequent, last longer than a few minutes, if you often feel extra beats (more than six a minute or in groups of three or more), if your resting pulse is over 100 without exercise, anxiety or fever, or if you have a heart condition, heart risk factors or a family history of heart problems (1, 6). Also see a doctor if palpitations started after a new supplement or medicine.

Seek emergency care. Call 911 if palpitations come with chest pain, shortness of breath, dizziness or light-headedness, unusual sweating or fainting, or if they do not go away (6, 1). Do not drive yourself.

How to bring this up with your doctor

What to ask for, by name. "Could we check a full blood count, ferritin, electrolytes including potassium and magnesium, and thyroid function?" If palpitations are frequent: "Could I have an ECG or a heart monitor?"

What to bring. Notes on when palpitations happen, how long they last, what they feel like, what you were doing, and every supplement, energy drink and medicine you take, including pre-workout products.

What to say, out loud. "I've had palpitations [N] times a week for [N] weeks. They feel like [racing / skipping / fluttering] and last about [N] minutes. I take [list]."

If you're told it's just anxiety. Ask: "Could we rule out anaemia, thyroid problems and electrolyte issues with blood tests, and is an ECG worthwhile?"

How long until you notice a difference? Most supplements take weeks, not days. See how long supplements take to work, and how to tell if one is working.

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How Welltory helps — and what it cannot do

The limits first. Welltory is a general wellness product, not a medical device. It does not diagnose arrhythmias, detect atrial fibrillation or tell you whether palpitations are dangerous. Call 911 if palpitations come with chest pain, shortness of breath, dizziness or light-headedness, unusual sweating or fainting, whatever any app shows.

What it can do is help you see the context of palpitations: how your heart rate, stress and sleep behaved around them.

Resting heart rate and morning state. On iOS, Battery starts each morning from your resting heart rate on waking and your sleep (Today screen). A resting heart rate drifting above your usual range over days can come with poor sleep, illness or stimulants. It is not a diagnosis, but it is worth mentioning to your doctor.

Tag the moment. On iOS with Apple Watch or Oura, when Welltory marks a stress episode and asks "What happened?", tap, type or talk: "palpitations", "pre-workout", "third coffee", "lying on left side", "period day 26". Over weeks, My Patterns shows which tags tend to appear with stress; some sections need a paid plan.

Sleep. Sleep Analysis uses Apple Watch or Oura data on iOS and syncs sleep from Samsung Health, Fitbit or Garmin Connect through Health Connect on Android (Sleep Analysis for Android). Short nights often come before palpitation-heavy days.

A record for your doctor. From the web app you can export a CSV (Dashboard → choose a chart → Export) (export guide) to bring alongside your symptom notes. Patterns are associations to discuss with your doctor, not a diagnosis.

How we made it

We based this article on NHS and MedlinePlus guidance on heart palpitations, FDA guidance on grapefruit and medicines, NCCIH guidance on St John's wort, NIH Office of Dietary Supplements fact sheets for magnesium and potassium, US National Center for Complementary and Integrative Health guidance on bitter orange, and a meta-analysis of omega-3 supplements and atrial fibrillation. Search questions came from what people in the United States most often ask about supplements and palpitations. For the product section, we checked every function against the Welltory Help Center on October 21, 2026.

Made with AI tools, then edited and fact-checked by the Welltory team. See our Editorial & AI policy.

Jane Smorodnikova, co-founder of Welltory, built the methodology behind how we read physiological data.

Written by Tatsiana Yashyna.

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