Some GLP-1-based medicines can produce a small increase in resting heart rate, which may be noticed as racing or pounding heartbeats. Palpitations can also occur indirectly through dehydration, low blood pressure or hypoglycemia. A palpitation, however, does not automatically mean that the medicine has caused an arrhythmia.
Yes. Some GLP-1-based medicines can modestly increase resting heart rate, and some patients may notice racing, pounding or stronger heartbeats. Current prescribing information reports an average increase of about 1–4 beats per minute with Wegovy (semaglutide) and about 1–3 beats per minute with Zepbound (tirzepatide) in major weight-management trials. Palpitations may also occur indirectly if nausea, vomiting or diarrhea causes dehydration or lower blood pressure, or if blood glucose falls too low in someone also using insulin or certain diabetes medicines. This does not mean GLP-1-based treatment routinely causes dangerous arrhythmias. Persistent, markedly irregular or worsening symptoms should be evaluated.
When Palpitations While Taking a GLP-1 Medicine Need Urgent Care
Seek urgent or emergency medical care for palpitations with:
- significant chest pain or pressure;
- severe or sudden shortness of breath;
- fainting or loss of consciousness;
- collapse;
- severe dizziness or near-fainting;
- a sustained very rapid or markedly irregular heartbeat while feeling seriously unwell;
- confusion or signs of poor circulation;
- severe persistent vomiting with inability to keep fluids down;
- symptoms of severe hypoglycemia such as confusion, seizure or loss of consciousness; or
- rapidly worsening symptoms.
Do not assume significant cardiovascular symptoms are simply a normal side effect of a weight-loss or diabetes medicine.
Which “GLP-1 Medications” Are We Talking About?
Patients often use the phrase “GLP-1 medication” for several related incretin-based drugs, but they are not pharmacologically identical.
| Medicine | Examples | How it works | 2026 status |
|---|---|---|---|
| Semaglutide | Wegovy, Ozempic | GLP-1 receptor agonist | Approved for specific indications |
| Tirzepatide | Zepbound, Mounjaro | Dual GIP and GLP-1 receptor agonist | Approved for specific indications |
| Retatrutide | No approved brand | Triple GIP, GLP-1 and glucagon receptor agonist | Investigational — not FDA-approved |
Tirzepatide combines GIP and GLP-1 receptor activity, while retatrutide additionally activates the glucagon receptor. Their cardiovascular effects therefore should not automatically be assumed to be identical.
Why Can GLP-1-Based Medicines Increase Heart Rate?
A small increase in resting heart rate has been consistently observed with several GLP-1 receptor agonists and newer incretin co-agonists.
The exact mechanism is still being studied.
Possible contributors include:
- direct effects on cardiac pacemaker activity;
- changes in autonomic nervous-system signaling;
- changes in sympathetic activity;
- weight-loss-related physiological adaptation; and
- individual differences in cardiovascular response.
A Small Average Increase Does Not Mean Everyone’s Pulse Rises by the Same Amount
Clinical-trial averages combine people whose heart rate changed very little with others who experienced larger increases.
This is why an individual patient with a persistent racing heartbeat deserves assessment even if the average increase reported in a drug trial was only a few beats per minute.
Wegovy, Semaglutide and Heart Palpitations
Wegovy contains semaglutide, a GLP-1 receptor agonist.
Current U.S. prescribing information states that Wegovy is associated with an increase in resting heart rate.
In weight-management trials, adults treated with injectable Wegovy had an average resting-heart-rate increase of approximately 1–4 beats per minute compared with placebo.
The prescribing information specifically instructs patients to inform their healthcare professional if they experience:
- palpitations; or
- a racing heartbeat while resting.
Persistent Resting Tachycardia Needs Prescriber Review
Current Wegovy prescribing information recommends regular heart-rate monitoring and states that sustained increases in resting heart rate may require discontinuation. Do not independently change a prescription because of one brief palpitation; contact the prescribing clinician so the heart rate, rhythm and other possible causes can be assessed.
What about Ozempic?
Ozempic also contains semaglutide, although its approved indications and doses differ from Wegovy.
Clinical trials of Ozempic have likewise shown a small average increase in heart rate.
Therefore, someone experiencing new racing or pounding sensations while using Ozempic should report the symptoms rather than assuming that a normal medication effect is the only possible explanation.
Can Zepbound Cause Heart Palpitations?
Zepbound contains tirzepatide, a dual GIP and GLP-1 receptor agonist.
In pooled major weight-management studies, current prescribing information reports an average heart-rate increase of approximately 1–3 beats per minute compared with no average increase in placebo-treated patients.
A small change in average trial heart rate is different from an individual patient experiencing a sudden racing rhythm, frequent skipped beats or a sustained high resting pulse.
What about Mounjaro?
Mounjaro and Zepbound contain the same active drug, tirzepatide, but they are marketed for different approved indications.
If palpitations develop during tirzepatide treatment, the important clinical question is what rhythm is occurring and whether the symptom relates directly to the medicine or indirectly to dehydration, hypoglycemia or another cause.
Retatrutide and Heart Palpitations
Retatrutide has generated considerable interest because of the large weight reductions reported in clinical trials.
However, retatrutide is fundamentally different from discussing an approved medicine such as Wegovy or Zepbound.
Retatrutide Is Not FDA-Approved as of August 2026
Retatrutide remains an investigational once-weekly triple agonist targeting GIP, GLP-1 and glucagon receptors.
Positive Phase 3 results have been announced, but Lilly currently plans to submit its FDA application in 2027.
Products being sold to consumers online as “retatrutide” are not approved commercial retatrutide. Their identity, dose, sterility and purity cannot be assumed.
What did the clinical trials show about heart rate?
In the published Phase 2 obesity trial, retatrutide produced a dose-dependent increase in heart rate.
The increase peaked around week 24 and declined later in the trial.
Investigators noted that the heart-rate effect was within the general range seen with other GLP-1-based therapies.
Cardiac arrhythmias were reported in the study, predominantly as mild to moderate events, but the trial was not designed to establish precise long-term arrhythmia risk.
Phase 3 Success Does Not Equal Regulatory Approval
Until regulatory review is complete, retatrutide should be described as investigational. Safety conclusions should come from formal clinical-trial data rather than unregulated products sold online under the retatrutide name.
Do GLP-1 Medications Cause Heart Arrhythmias?
Current evidence does not support the simple conclusion that GLP-1 receptor agonists routinely cause atrial fibrillation or other major arrhythmias.
Large randomized-trial meta-analyses have generally not shown a significant overall increase in major cardiac arrhythmias.
More recent analyses have even reported lower rates of atrial fibrillation in people receiving GLP-1-based therapies, including semaglutide.
Heart Rate Increase and Arrhythmia Risk Are Different Questions
A medicine may increase average resting pulse slightly without increasing atrial fibrillation or ventricular arrhythmias across a large population.
Conversely, a reassuring population-level safety result cannot determine what rhythm is occurring in one person who develops new palpitations.
Why Can My Heart Race Even if the Medicine Did Not Cause an Arrhythmia?
Several secondary effects of treatment can produce palpitations without representing a primary electrical effect of the drug.
Dehydration
Nausea, vomiting or diarrhea can reduce circulating fluid volume, especially during dose escalation. The heart may compensate by beating faster.
Low blood pressure
Tirzepatide and semaglutide weight-management trials have reported hypotension and orthostatic symptoms, sometimes in association with gastrointestinal fluid loss.
Hypoglycemia
Low blood glucose can cause sweating, tremor, anxiety and a rapid heartbeat, particularly when GLP-1-based treatment is combined with insulin or an insulin-secretagogue medicine.
Caffeine or nicotine
Coffee, energy drinks, vaping or nicotine pouches may contribute additional cardiovascular stimulation and confuse the relationship between the medication and the symptom.
Anxiety
Feeling an unexpected increase in pulse can itself trigger anxiety, adrenaline release and stronger heartbeat awareness.
Another medical condition
Anemia, thyroid disease, fever, an independent arrhythmia or another condition may begin while someone happens to be taking a GLP-1 medicine.
Vomiting, Diarrhea, Dehydration and GLP-1 Palpitations
Gastrointestinal adverse effects are among the most common problems with GLP-1-based therapies, particularly during dose escalation.
Significant fluid loss can produce:
- thirst;
- dry mouth;
- reduced urine output;
- dizziness when standing;
- lower blood pressure;
- weakness; and
- a faster compensatory heart rate.
Zepbound prescribing information specifically notes that hypotension has occurred in association with gastrointestinal adverse events and dehydration.
See dehydration and heart palpitations .
Persistent Vomiting + Racing Heart Deserves More Than “Drink More Water”
Inability to keep fluids down, reduced urination, severe dizziness, fainting or persistent tachycardia can indicate clinically important volume depletion and may require medical assessment.
Can Low Blood Sugar Cause Palpitations While Taking These Medicines?
Yes, particularly in people with diabetes who also take insulin or medicines that increase insulin secretion.
Hypoglycemia may cause:
- racing heartbeat;
- sweating;
- shakiness;
- hunger;
- anxiety;
- dizziness;
- difficulty concentrating; and
- confusion when more severe.
GLP-1-based therapies used alone generally have a lower hypoglycemia risk than insulin or sulfonylureas, but combination treatment changes that risk.
If you use glucose-lowering medication, check glucose according to your diabetes plan when appropriate. A persistently irregular rhythm or symptoms occurring with normal glucose may require a different explanation.
Why Did My Palpitations Start After Increasing the Dose?
Timing around dose escalation can be useful information.
Higher doses may produce:
- more gastrointestinal symptoms;
- greater fluid loss;
- changes in resting heart rate;
- reduced food intake; and
- greater likelihood of hypoglycemia when combined with other diabetes medicines.
This makes a symptom diary particularly useful.
Record:
- the date of each dose;
- the dose level;
- when palpitations begin;
- resting heart rate;
- whether the pulse feels regular or irregular;
- vomiting or diarrhea;
- fluid intake;
- blood glucose when relevant;
- caffeine or nicotine use; and
- associated dizziness, breathlessness or chest discomfort.
Should You Stop Zepbound, Wegovy or Another GLP-1 Medicine Because of Palpitations?
Do not make an unsupervised medication change solely because of one brief palpitation unless you are dealing with an emergency reaction requiring urgent care.
Instead, contact the prescribing clinician when:
- palpitations repeatedly follow each dose;
- your resting pulse remains noticeably higher than your usual baseline;
- the heartbeat feels irregular;
- symptoms last several minutes or longer;
- episodes are becoming more frequent;
- you are having substantial vomiting or diarrhea;
- blood pressure is repeatedly low with symptoms; or
- you use other medicines that affect glucose, heart rate or blood pressure.
Wegovy’s current prescribing information specifically addresses sustained increases in resting heart rate. Other medicines have different labeling. The prescriber should therefore review the exact medication rather than treating every “GLP-1” product as identical.
What Can You Do if Mild Palpitations Occur?
If you feel otherwise well and have no emergency warning signs:
- Sit and rest.
- Note the heart rate if you can measure it safely.
- Notice whether the pulse feels regular or irregular.
- Record how long the episode lasts.
- Consider whether vomiting, diarrhea or poor fluid intake has occurred.
- Check glucose according to your diabetes plan if hypoglycemia is possible.
- Avoid adding excessive caffeine, nicotine or other stimulants.
- Contact your prescriber if symptoms recur or resting heart rate remains elevated.
Do Not Self-Treat an Unknown Rhythm
Do not take extra beta-blockers, antiarrhythmics, potassium, high-dose magnesium or another person’s medication to counteract palpitations from a GLP-1-based drug.
How Are Palpitations During GLP-1 Treatment Evaluated?
Medication review
The clinician should confirm:
- the exact drug;
- current dose;
- how long you have been taking it;
- recent dose increases;
- other diabetes medications;
- blood-pressure medicines;
- caffeine and nicotine exposure; and
- any non-prescription or compounded products.
Heart rate and blood pressure
Resting pulse and blood pressure can help identify persistent tachycardia, hypotension or orthostatic changes.
See heart palpitations and blood pressure .
12-lead ECG
An ECG during symptoms can determine whether the rhythm is:
- normal sinus rhythm;
- sinus tachycardia;
- PACs or PVCs;
- atrial fibrillation;
- SVT; or
- another rhythm abnormality.
Holter, patch or event monitoring may be useful when episodes recur but are not present during the office ECG.
See heart palpitations despite a normal ECG .
Blood tests
Depending on the presentation, testing may include:
- blood glucose;
- electrolytes;
- kidney function;
- complete blood count;
- thyroid function; and
- other testing directed by symptoms.
What if My Heart Rate Is Normal but I Still Feel Palpitations?
This can happen.
Palpitations describe awareness of the heartbeat rather than simply a high beats-per-minute number.
A person may feel:
- a premature beat;
- a stronger contraction;
- a brief pause and thump;
- anxiety-related heartbeat awareness; or
- normal sinus rhythm that simply feels unusually prominent.
This is why a smartwatch pulse reading of 75 bpm does not automatically prove that every heartbeat is normal, while a normal ECG captured during the exact symptom is much more informative.
Dr. Albana’s Note
When someone tells me, “My heart started racing after my GLP-1 injection,” I first confirm which medicine they are actually taking. Semaglutide, tirzepatide and retatrutide are not the same drug, and retatrutide is still investigational. I then look at timing: Did the symptom begin after a recent dose increase? Has the patient been vomiting or eating and drinking much less? Are they also taking insulin or a sulfonylurea? Is the pulse simply somewhat faster, or is it truly irregular? A small medication-related increase in resting heart rate is documented with several of these therapies, but I do not use that fact to explain away every new palpitation. If the rhythm is persistent or irregular, documenting it with an ECG or monitor gives us a much safer answer.
When Should You Contact Your Prescriber?
Contact the clinician managing your treatment if:
- your resting heart rate remains persistently higher than usual;
- palpitations repeatedly occur after injections or dose increases;
- the heartbeat feels irregular;
- episodes repeatedly last several minutes or longer;
- you are becoming dizzy or weak;
- you have recurrent low blood pressure;
- you have significant nausea, vomiting or diarrhea;
- you have recurrent low glucose readings;
- you have known heart disease or a previous arrhythmia; or
- the symptoms continue even when other obvious triggers have been corrected.
For broader risk guidance, see when to worry about heart palpitations .
Urgent Warning Signs
Seek urgent or emergency medical care for:
- significant chest pain or pressure;
- severe or sudden shortness of breath;
- fainting or collapse;
- severe dizziness or near-fainting;
- a sustained very rapid or markedly irregular heartbeat while feeling seriously unwell;
- confusion, seizure or loss of consciousness;
- severe dehydration with very low urine output;
- severe hypoglycemia; or
- rapidly worsening symptoms.
Most Asked Questions
Can GLP-1 medications cause heart palpitations?
They can contribute. Several GLP-1-based medications cause a small average increase in resting heart rate, and some patients may notice racing or pounding sensations. Palpitations can also result indirectly from dehydration, hypotension or hypoglycemia.
Can Wegovy cause heart palpitations?
Wegovy prescribing information recognizes an increase in resting heart rate and specifically advises patients to report palpitations or racing heartbeat while at rest.
Can Ozempic cause a racing heart?
Ozempic contains semaglutide, and its clinical trials have shown a small average increase in heart rate. A sustained or irregular racing heartbeat still deserves evaluation rather than being assumed to be a routine effect.
Can Zepbound cause heart palpitations?
Zepbound treatment has been associated with a small average increase in heart rate. Palpitations can also occur if gastrointestinal side effects lead to dehydration or lower blood pressure.
Can Mounjaro cause heart palpitations?
Mounjaro contains tirzepatide, the same active drug found in Zepbound. Tirzepatide can modestly increase average heart rate, although symptoms alone cannot determine whether an actual arrhythmia is present.
Can retatrutide cause heart palpitations?
Published retatrutide trials have shown dose-dependent increases in heart rate. However, retatrutide remains investigational and is not FDA-approved as of August 2026, so its full safety profile is still being established.
Is retatrutide available to buy?
No approved retatrutide product is currently available for public use. Retatrutide remains investigational. Products sold online under that name outside authorized clinical trials cannot be assumed to contain authentic retatrutide or a reliable dose.
Do GLP-1 drugs cause atrial fibrillation?
Randomized-trial evidence does not show a clear overall increase in atrial fibrillation from GLP-1-based therapies. Some analyses have actually reported lower AF rates, but that does not rule out an arrhythmia in an individual who develops new symptoms.
Why does my heart race after my GLP-1 injection?
Possible explanations include the medication’s direct heart-rate effect, dehydration from nausea or diarrhea, low blood pressure, hypoglycemia when combined with certain diabetes medicines, anxiety, stimulants or an unrelated arrhythmia.
Are palpitations more likely after increasing the dose?
They may become more noticeable around dose escalation because gastrointestinal symptoms and fluid loss can be stronger and because cardiovascular responses vary by dose and individual. Recurrent symptoms should be discussed with the prescriber.
Can dehydration from GLP-1 medicines cause palpitations?
Yes. Vomiting, diarrhea or markedly reduced fluid intake can lower circulating volume, producing a faster compensatory heart rate, dizziness and sometimes lower blood pressure.
Can hypoglycemia cause palpitations while taking a GLP-1 medicine?
Yes. The risk is particularly relevant when treatment is combined with insulin or an insulin-secretagogue medication. Low glucose can cause racing heart, sweating, tremor and anxiety.
Should I stop Zepbound or Wegovy if I get palpitations?
Do not make an unsupervised medication change because of one brief episode. Recurrent palpitations or a sustained increase in resting heart rate should be reviewed promptly with the prescribing clinician, who can apply the specific instructions for the medication you use.
Can a normal ECG miss GLP-1-related palpitations?
Yes, if the episode ended before the ECG was recorded. Recurrent symptoms may require a Holter, patch or event monitor to document the rhythm during the actual sensation.
When should GLP-1-related palpitations worry me?
Seek urgent care for palpitations with chest pain, severe breathlessness, fainting, collapse, severe dizziness, severe hypoglycemia or a sustained very rapid or markedly irregular heartbeat while feeling seriously unwell.
Related Heart Palpitation Guides
Medical References
- U.S. Food and Drug Administration. Zepbound (tirzepatide) Prescribing Information. Current 2026 labeling.
- U.S. Food and Drug Administration. Wegovy (semaglutide) Prescribing Information. Current 2026 labeling.
- U.S. Food and Drug Administration. Ozempic (semaglutide) Prescribing Information.
- Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 Trial. New England Journal of Medicine. 2023.
- Eli Lilly and Company. What to Know About Retatrutide. Updated July 2026.
- Eli Lilly and Company. TRIUMPH Phase 3 Retatrutide Clinical Trial Results. 2026.
- Zhang Y, et al. Effect of GLP-1 Receptor Agonists on Heart Rate in Non-Diabetic Individuals With Overweight or Obesity: Systematic Review and Network Meta-analysis. European Journal of Medical Research. 2026.
- Karakasis P, et al. Effect of GLP-1 Receptor Agonists and Co-agonists on Atrial Fibrillation Risk in Overweight or Obesity. Metabolism. 2026.
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.