Can GLP-1s Cause Heart Palpitations? Ozempic, Heart Rate and AFib

GLP-1 medications like Ozempic can contribute to heart palpitations. They nudge resting heart rate up a little: in the placebo-controlled trials summarized in the Ozempic prescribing information, resting heart rate went up by an average of 2 to 3 beats per minute. When a racing or fluttering heart does show up on a GLP-1, the first things to check are ordinary ones: dehydration, low potassium, low blood sugar (mainly if you also take insulin or a sulfonylurea), a blood pressure medicine that has become too strong, and the extra coffee that fills in when you're eating less.

Palpitations that come with chest pain, trouble breathing or fainting need emergency care. A racing heartbeat while you're sitting still is worth a call to your provider. That second instruction comes straight from the Wegovy label (Wegovy is semaglutide, the same medicine as Ozempic, at weight loss doses).

The heart rhythm research has a second, more encouraging half too. A study of 12,812 patients published in the journal Heart Rhythm in 2026 found that people taking a GLP-1 developed atrial fibrillation (AFib) less often than similar patients who weren't, even when they didn't lose weight. Both halves are below, along with who should keep a closer eye on heart rhythm during treatment.

Key Points

• Semaglutide and tirzepatide raise resting heart rate by a few beats per minute on average, according to the FDA prescribing information for Ozempic, Wegovy and Zepbound.
• Dehydration, low potassium and low blood sugar can all cause palpitations (low blood sugar mainly if you also take insulin or a sulfonylurea), and all three are more likely when nausea cuts how much you eat and drink.
• Racing heartbeat at rest: the Wegovy label says report it.
• Chest pain, trouble breathing, fainting, or palpitations that won't stop: call 911.
• A 2026 study linked GLP-1 use to a lower rate of AFib. It shows an association. It can't prove the drug caused the drop, and no one should start a GLP-1 to prevent AFib.

Can Ozempic and Other GLP-1s Cause Heart Palpitations?

They can contribute. Palpitations are the feeling of your own heartbeat: pounding, fluttering, racing, or a skipped beat. Two things are going on with GLP-1 medications.

The first is the medication itself. Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) nudge resting heart rate up a little, by a few beats per minute on average.

The second is everything the medication changes around it. You eat less. You often drink less. Some weeks you deal with nausea, vomiting or diarrhea. Those shifts can bring on palpitations by themselves, and they're the part you can do something about.

Do GLP-1 Medications Raise Your Heart Rate?

Yes, slightly. GLP-1 medications are linked to a small increase in resting heart rate, and on its own that is usually harmless. What tends to make the heart feel jumpy is dehydration and low electrolytes like potassium and magnesium, which are easy to run low on when nausea and a smaller appetite cut how much you eat and drink. A racing heart, pounding, fluttering, or new lightheadedness after starting the medication is worth reporting to your provider, because simple lab work often finds the cause.

Each label reports the size of the increase seen in its trials. The Wegovy figure comes from its weight loss trials.

Medication	Average rise in resting heart rate
Ozempic (semaglutide)	2 to 3 beats per minute
Wegovy (semaglutide)	1 to 4 beats per minute
Zepbound (tirzepatide)	1 to 3 beats per minute

An average can hide a big jump in one person. The Wegovy label also reports that more people on the drug than on placebo had a bigger jump at some visit during the trials, which is why it tells prescribers to check heart rate at regular intervals and tells patients to speak up about palpitations or a racing heartbeat at rest. If the resting rate stays up, the label says to stop the medication. Make that call with your provider, not on your own.

What Causes Palpitations on a GLP-1?

The Cleveland Clinic lists dehydration, low blood sugar, low potassium, caffeine, alcohol, anxiety and certain medicines among the common causes of palpitations. Several of those line up neatly with life on a GLP-1. Other medicines on that list, including thyroid medicine and the decongestants in some cold medicines, can do it too, so bring your full medication list to appointments.

Dehydration and low potassium

Less food usually means less fluid, and vomiting or diarrhea pulls more out. MedlinePlus lists diarrhea and vomiting among the common causes of low potassium, and a feeling of skipped beats or palpitations among its symptoms. Magnesium is the other electrolyte worth watching when you're eating much less than you used to. Both are on our standard panel, so this is a quick question to answer.

Starting the medication and each dose increase

The Ozempic prescribing information names the start of treatment and each dose increase as the time to watch for fluid loss from stomach side effects. If your heart started acting up the same week your dose went up, mention the timing. It helps your provider sort the medication from everything else.

Low blood sugar, if you take other diabetes medicines

This one applies mostly to people with type 2 diabetes. The Ozempic label warns that combining it with insulin or a sulfonylurea raises the risk of low blood sugar, and that the dose of those medicines may need to come down. NIDDK lists a heart that beats too fast or not steadily among the signs of low blood sugar, along with feeling shaky, dizzy or confused. If you're on either type of medicine and your heart races, check your glucose. If it's low, treat it the way your care plan says. If someone is confused, can't swallow safely, or passes out, call 911.

Lightheadedness and blood pressure medicine

In the Wegovy and Zepbound trials, low blood pressure showed up more often in people who were also taking blood pressure medicine, and some cases were tied to stomach side effects and fluid loss, per the Zepbound label. Feeling faint or dizzy when you stand, especially alongside a pounding heart, is worth reporting. Don't cut or stop a blood pressure medicine on your own. Your provider adjusts it.

Caffeine, alcohol and stress

If you've been leaning on coffee to get through low-energy days early in treatment, notice that. Caffeine and alcohol are both on the Cleveland Clinic's list, and so are stress and anxiety. None of these is specific to GLP-1s. They're just easy to overlook when you're sure the new medication is to blame. If anxiety has been part of the picture for a while, our post on the physical causes of anxiety worth testing goes further.

Your thyroid

An overactive thyroid can push the heart into a fast or irregular rhythm, and the National Heart, Lung, and Blood Institute (NHLBI) lists it as an AFib risk factor. A thyroid panel is part of our standard labs, and our thyroid and adrenal program picks up from there if something turns up.

When Should You Worry About a Racing Heart on Ozempic?

Call 911 if palpitations won't stop, or if they come with any of these, per the Cleveland Clinic and the NHS:

• Pain, pressure or tightness in your chest, neck, jaw, arms or upper back
• Trouble breathing
• Feeling faint, or passing out

Call your provider soon if:

• Your heart races or pounds while you're resting (the situation the Wegovy label names)
• Palpitations keep coming back, or come more often
• They last longer than a few minutes
• You feel dizzy or lightheaded, especially on standing
• You've been vomiting, have diarrhea, or can't keep fluids down
• You have a heart condition or a family history of one

Can Ozempic Cause AFib? What the Research Shows

A large 2026 study points the other way. Atrial fibrillation is an irregular and often rapid heartbeat that starts in the heart's upper chambers. The NHLBI calls it one of the most common types of irregular heart rhythm, notes that it can happen without any symptoms, and warns that untreated it can lead to stroke or heart failure.

In April 2026, researchers at the University of Virginia published a retrospective cohort study in Heart Rhythm, the Heart Rhythm Society's peer-reviewed journal. They followed 12,812 patients who started a GLP-1 at a single academic medical center between 2020 and 2023, and compared them with a matched group of patients with similar AFib risk factors who didn't take one.

What they reported:

• GLP-1 use was associated with a lower risk of AFib, a hazard ratio of 0.67, or roughly a third lower over the study period.
• The lower risk held across every weight change group, including patients who gained weight.
• Among the individual medications, only semaglutide reached statistical significance.
• The drop in AFib risk appeared after 24 months of use.

Excess weight is a known AFib risk factor, so some benefit was expected from any drug that helps people lose weight. The surprise is that the pattern held in people who didn't lose weight. The authors read that as a sign GLP-1s may have a heart rhythm effect of their own, separate from the scale. The 24-month detail matters too. Whatever this effect is, it showed up after two years of treatment.

If you want a refresher on how these medications work and the side effects that are normal, our guide to GLP-1 medications covers each option.

What This Finding Does Not Mean

Before anyone reframes a weekly injection as heart medicine, some honesty about the limits.

A retrospective cohort looks back at medical records. It can show a strong association, and 12,812 patients is a meaningful sample. It can't prove cause and effect, because people who get prescribed a GLP-1 may differ from those who don't in ways matching can't fully capture. It also came from one academic center, and only semaglutide reached significance on its own, so the result can't simply be stretched to every GLP-1.

So nobody should start a GLP-1 medication to prevent or treat atrial fibrillation. That claim is ahead of the evidence, and a clinic willing to make it should make you wonder what else it exaggerates. Patients who already have AFib need to stay under a cardiologist's care.

The fair way to hold this finding: a promising signal that GLP-1 medications may be doing something for the cardiovascular system that the scale doesn't show. It widens what "working" can mean. Who the medication is for stays the same.

That matters most in plateau weeks, when the dose is right, the habits are holding, and the scale won't move. The scale measures one thing. It says nothing about blood sugar, inflammation or heart rhythm. We track progress with an InBody body composition scan at every visit and with repeat labs compared against your own baseline, so a slow month on the scale isn't the only data point. Our post on why weight loss stalls on semaglutide covers what we check when it does.

Who Should Pay Closer Attention to Heart Rhythm on a GLP-1

Most people take these medications without rhythm problems. A few groups should make sure heart rhythm is part of the conversation before starting and during treatment. Most of these are on the NHLBI's list of AFib risk factors:

• A personal or family history of AFib, palpitations or other rhythm problems
• High blood pressure or existing heart disease
• Diagnosed or suspected sleep apnea
• Diabetes (and if you take insulin or a sulfonylurea, the low blood sugar risk above)
• Chronic kidney disease
• An overactive thyroid
• Drinking large amounts of alcohol, especially binge drinking
• Anyone who notices a racing heart, fluttering or new lightheadedness after starting

Cardiac history is one of the things our medical team weighs in every new patient file. Dr. Paul Laband, MD, a board-certified internal medicine physician with over 25 years of experience in primary care and hospital medicine, is part of our heart health team. If you already see a cardiologist, keep them in the loop. A weight loss program should work alongside your cardiologist.

Why Labs and Supervision Matter

The GLP-1 boom created two very different ways to get these medications. One is a monitored medical program. The other is a checkout page.

The checkout-page version ships medication after a short intake form. Baseline labs may be skipped, thyroid status and potassium may never be checked, and follow-up is often up to you. If your heart races at 2 a.m. three weeks into a dose increase, you're on your own with a search bar.

A supervised program looks different from the first week. Before prescribing anything, our providers review an 80+ biomarker panel through advanced testing. It includes thyroid function, electrolytes, kidney function and metabolic markers, the same systems that come up when a heart starts racing on treatment. Labs can be drawn in our office, or at a partner lab near you. Those baselines give your provider something to compare against at every follow-up. Weighing semaglutide against tirzepatide? We compared them in semaglutide vs tirzepatide, and the four brand names in Zepbound vs Mounjaro vs Wegovy vs Ozempic.

There's a longer view, too. If GLP-1 medications do turn out to protect the heart, the study suggests the payoff takes years, which is the whole point of healthy aging medicine. Years of treatment take years of monitoring. Keeping muscle while you lose fat is part of that, and our page on muscle loss explains why.

How Med Matrix Handles GLP-1 Weight Loss

Our semaglutide weight loss program sits inside our broader medical weight loss program, and both are built on functional medicine first and a prescription second. Every patient goes through the same five steps.

1. Free Discovery Call. A patient coordinator hears what you're dealing with, including any heart history, and matches you with the right provider.
2. 80+ Biomarker Test & Full Body Scan. A blood panel that includes thyroid, electrolytes, kidney function and metabolic markers, plus an InBody 770 body composition scan.
3. Medical Team Reviews Everything. The team reads your labs, scan and history together before you sit down with a provider, including anything relevant to your heart.
4. 60-Minute Provider Consultation. Every result gets explained, and your plan gets built with you in the room, whether it includes a GLP-1 or starts somewhere else.
5. Ongoing Support & Progress. Follow-up visits, an InBody scan at every visit, retesting against your own baseline, and dose adjustments when something feels off. Racing heart included.

Frequently Asked Questions

Can GLP-1 medications cause heart palpitations?

They can contribute. GLP-1 medications raise resting heart rate by a few beats per minute on average, and dehydration, low potassium or low blood sugar (mainly if you also take insulin or a sulfonylurea) can make the heart feel jumpy, all of which are more likely when you're eating and drinking less. A racing heart, pounding, chest fluttering or new lightheadedness after starting the medication is worth reporting to your provider. Simple lab work can find the cause.

Does Ozempic increase heart rate?

Slightly. The Ozempic prescribing information reports an average rise in resting heart rate of 2 to 3 beats per minute in its placebo-controlled trials. The Wegovy label reports 1 to 4 beats per minute in its weight loss trials and tells patients to report palpitations or a racing heartbeat at rest.

Can Ozempic cause AFib?

One large study points the other way. Published in 2026 in the journal Heart Rhythm, it followed 12,812 patients and found GLP-1 use was associated with a lower rate of atrial fibrillation, and semaglutide, the drug in Ozempic, was the only individual medication with a statistically significant result. It's a retrospective study, so it shows an association rather than proof. New palpitations or an irregular pulse on any medication should still be checked.

When are palpitations on a GLP-1 an emergency?

Call 911 if palpitations won't stop, or if they come with chest pain or pressure, trouble breathing, feeling faint or fainting. Palpitations while resting, ones that keep coming back, ones that last longer than a few minutes, or ones that come with dizziness are a reason to call your provider soon.

Can I drink coffee on Ozempic?

Caffeine is a common trigger for palpitations in anyone, on a GLP-1 or not. If your heart has been racing, cut back and see whether it settles, drink enough water, and tell your provider if it doesn't.

Should I start semaglutide to prevent atrial fibrillation?

No. The 2026 finding is observational, and GLP-1 medications are not approved or proven to prevent or treat AFib. The decision to start semaglutide should rest on your weight, your metabolic health, your labs and your goals. Any heart rhythm benefit, if the research holds up, is a bonus on top of that, never the reason to start.

I already have AFib. Can I still take a GLP-1 medication?

Many people with heart conditions do take GLP-1 medications, but that decision belongs to your providers, made with your full history in view. In our clinic, your cardiac history is reviewed before anything is prescribed, and your cardiologist should stay part of the picture throughout.

What labs matter for heart rhythm while on a GLP-1?

Electrolytes (especially potassium and magnesium), thyroid function, kidney function, and metabolic markers like fasting glucose and insulin all feed into the rhythm picture. Our new-patient panel covers 80+ biomarkers in one draw, so these are checked before treatment starts and rechecked as treatment goes on.

If you've been thinking about medical weight loss but the mail-order route makes you uneasy, that instinct is a good one. Get a program where someone actually reads your labs and your heart history, and measures progress by more than the scale. Start Feeling Like Yourself Again with a free discovery call.