Does Tadalafil Cause Heart Palpitations?

Tadalafil can cause heart palpitations, but it's uncommon. The SmPC classifies palpitations as an uncommon adverse effect, meaning they affect between 1 in 100 and 1 in 1,000 patients. Most people taking tadalafil never notice any cardiac sensations at all.

Why tadalafil occasionally triggers a racing heart#

Tadalafil works by relaxing the smooth muscle in blood vessel walls, which widens the vessels and lowers blood pressure slightly. Your body detects this drop and responds with a compensatory reflex: the heart beats a little faster to keep blood pressure stable. This is called reflex tachycardia, and it's not a sign that tadalafil is directly stimulating your heart. It's simply your cardiovascular system doing its job.

The sensation tends to peak around 2 hours after you take a tablet, which is when tadalafil reaches its highest concentration in the blood. If you notice your heart thumping during this window, that's the most likely explanation.

It's also worth separating three things patients often group together:

• Palpitations mean you become aware of your own heartbeat. It may feel fast, forceful, or irregular.
• Tachycardia means your heart rate is objectively above 100 beats per minute.
• Arrhythmia means the heart's rhythm is genuinely abnormal, not just fast.

Tadalafil most commonly produces the first of these. True tachycardia is less frequent. The SmPC does list palpitations and tachycardia as uncommon effects, but does not establish a clear causal link to arrhythmia in otherwise healthy men.

Does dose make a difference?#

Lower doses produce less vasodilation, so cardiac sensations are generally less likely at 2.5 mg or 5 mg daily than at 10 mg or 20 mg taken on demand. Men taking low-dose daily tadalafil (often prescribed for benign prostatic hyperplasia, or BPH) typically report fewer cardiovascular side effects than those taking higher as-needed doses. This reflects the smaller peak plasma concentration with continuous low-dose dosing compared to the sharper spike from an on-demand 20 mg tablet.

What makes palpitations more likely?#

Several factors can amplify the vasodilatory effect and increase the chance of noticing cardiac sensations:

• Alcohol. Drinking more than 2 to 3 units alongside tadalafil adds its own blood-pressure-lowering effect. Large amounts (five or more drinks) substantially increase the risk of dizziness, flushing, and a faster heart rate.
• Grapefruit juice. It inhibits an enzyme (CYP3A4) that breaks down tadalafil in the gut, which can raise plasma levels above what the dose label predicts. The clinical significance of this effect is considered modest, but it is worth bearing in mind if you take tadalafil regularly.
• Heat and dehydration. Saunas, hot baths, and exercise all dilate blood vessels further and can compound the cardiovascular response.
• Performance anxiety. Sexual activity naturally raises heart rate. If you're anxious, adrenaline does too. What you feel as a racing heart after taking tadalafil may partly, or even entirely, be psychological rather than pharmacological.

Alpha-blockers (such as tamsulosin, sometimes prescribed alongside tadalafil for BPH) also lower blood pressure. Taking them together requires care, and your prescriber should already have flagged this during your assessment.

When to call 111 or 999#

Mild awareness of your heartbeat that passes within a few minutes is unlikely to need medical attention. Call 111 if palpitations are persistent, come with dizziness, or happen repeatedly each time you take tadalafil. Call 999 immediately if you have chest pain, severe shortness of breath, or feel like you might faint. Tell the call handler when you last took tadalafil and at what dose, because this affects which treatments emergency staff can safely give you.

Nitrates and tadalafil must never be used together. If you are taking tadalafil, nitrates (such as a glyceryl trinitrate (GTN) spray used for angina) must not be taken until at least 48 hours after your last tadalafil dose. Conversely, if you have recently used a short-acting nitrate, you should wait at least 24 hours before taking tadalafil. This combination can cause a sudden and dangerous fall in blood pressure. If you carry a GTN spray, make sure your prescriber knows you're also taking tadalafil. Tadalafil is also absolutely contraindicated with riociguat, a medicine used for pulmonary hypertension, for the same reason.

If you have a pre-existing heart condition#

For men with controlled hypertension or stable coronary artery disease, tadalafil is often safe, but it requires proper assessment. The MHRA and NICE both recommend that cardiovascular risk is evaluated before prescribing any PDE5 inhibitor. Men with recent heart attacks, unstable angina, or certain rhythm disorders — including some presentations of atrial fibrillation — should discuss tadalafil specifically with a cardiologist before use.

For context on how tadalafil compares to sildenafil from a cardiac perspective, our guide on Can Viagra Cause a Heart Attack? covers the broader safety picture for PDE5 inhibitors.

If you want to understand how timing and dose affect your overall experience with tadalafil, the tadalafil dosage guide explains the differences between daily and on-demand regimens in plain terms.