Introduction
Heart conditions such as heart failure, angina, and irregular heart rhythms (arrhythmias) are common, especially in people with diabetes or obesity.
Medicines such as Wegovy (semaglutide) and Mounjaro (tirzepatide) are highly effective for weight loss and blood sugar control. But if you have a heart condition, you may wonder whether these medicines are safe.
GLP-1 Medicines and the Heart: What the Evidence Says
Weight loss benefits: By lowering weight, blood pressure, and cholesterol, GLP-1 medicines reduce strain on the heart and improve overall cardiovascular risk (1,2).
Heart failure:
GLP-1 medicines improve weight and blood sugar but have not consistently reduced hospitalisations for heart failure.
The SmPC for semaglutide (Wegovy) notes: “There is no experience in patients with congestive heart failure NYHA class IV, therefore use is not recommended in this group.”
Mounjaro has been studied in obesity-related heart failure with preserved ejection fraction (HFpEF), showing promising results in reducing hospitalisations (3).
Angina (chest pain):
Weight loss may reduce angina over time, but GLP-1s can cause nausea or mild increases in heart rate, which in sensitive patients may mimic or worsen chest discomfort (4).
Irregular heart rate (arrhythmias):
GLP-1s may cause a small rise in resting heart rate (around 2–4 beats per minute).
For most people, this is harmless. However, the Mounjaro (tirzepatide) product information advises caution in patients with cardiac conditions that might be worsened by increased heart rate.
Overall: GLP-1 medicines are not contraindicated in most heart conditions. In fact, they are often beneficial. But they must be used with careful monitoring, especially in advanced heart failure or patients with rhythm problems.
What Patients Should Consider
1.Starting treatment
Inform your GP or Cardiologist that you intend to start using weightloss injections, so they can advise if it's safe, review your heart medicines and arrange any monitoring.
Inform your weight loss provider of all medical conditions and regular medications that you take.
2. During treatment
Monitor your heart rate and blood pressure regularly (many home BP machines measure pulse).
Report to your GP if you experience:
- Worsening breathlessness
- New or more frequent chest pain
- Palpitations, fluttering, or a racing heartbeat
Remember:
Semaglutide (wegovy) is not recommended in very advanced heart failure (NYHA class IV).
Tirzepatide (mounjaro) should be used with caution if you have arrhythmias or conditions sensitive to heart rate increases.
Never stop or change your existing heart medicines without GP advice.
3. After weight loss
Many patients notice improved stamina, less breathlessness, and reduced angina symptoms as weight comes off.
Your GP may review your medications if your heart condition stabilises.
Continue to attend all follow-ups as heart conditions usually need lifelong monitoring.
4. Lifestyle Tips to Support Heart Health
- Limit salt intake: Too much salt worsens fluid retention and blood pressure.
- Heart-healthy diet: Vegetables, wholegrains, lean protein, and minimal processed or fried foods.
- Stay active (safely): Walking or light exercise helps fitness, but stop if you feel chest pain, dizziness, or palpitations.
- Daily weight checks (heart failure): Rapid weight gain (>2kg in 2–3 days) may mean fluid build-up.
- Avoid smoking and limit alcohol: Both increase heart strain and arrhythmia risk.
- Take medicines regularly: Continue all prescribed heart medicines alongside GLP-1 treatment.
When to Seek Medical Advice Urgently
Seek urgent medical help if you develop:
- Chest pain or pressure (especially at rest or lasting more than a few minutes)
- Sudden or severe breathlessness
- Fainting, collapse, or extreme dizziness
- A racing or irregular heartbeat that does not settle
- Rapid swelling in the legs or abdomen with sudden weight gain
If severe, call 999 immediately.
Summary
GLP-1 medicines such as Wegovy and Mounjaro can help reduce weight and improve heart risk factors.
They are not contraindicated in most patients with heart disease.
Semaglutide is not recommended in very advanced heart failure.
Mounjaro should be used with caution in patients with heart rhythm disorders or conditions sensitive to heart rate increases.
With GP or cardiologist supervision, regular monitoring, and healthy lifestyle changes, GLP-1 medicines can usually be used safely in people with heart conditions as long as they receive the appropriate monitoring and supervision by their GP.
References
- Marso SP, Daniels GH, Brown-Frandsen K, et al. Liraglutide and cardiovascular outcomes in type 2 diabetes. N Engl J Med. 2016;375:311–22.
- Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384:989–1002.
- Margulies KB, Hernandez AF, Redfield MM, et al. Effects of liraglutide on clinical stability among patients with advanced heart failure and reduced ejection fraction: The FIGHT trial. JAMA. 2016;316(5):500–8.
- Kristensen SL, Rørth R, Jhund PS, et al. Cardiovascular outcomes with GLP-1 receptor agonists in patients with type 2 diabetes: A meta-analysis. Lancet Diabetes Endocrinol. 2019;7(10):776–85.
- Sun F, Wu S, Guo S, et al. Effect of GLP-1 receptor agonists on heart rate, blood pressure and hypertension in type 2 diabetes: A systematic review and meta-analysis. Diabetes Obes Metab. 2015;17(11):1070–80.
- European Medicines Agency. Ozempic SmPC. Link . Accessed 2025.
- Medicines.org.uk. Mounjaro SmPC. Link. Accessed 2025.