Tadalafil and Aspirin: Can You Take Them Together?

Takes less than 2 minutes to complete 100% online

Key takeaways

• Tadalafil and aspirin do not have a major direct interaction and can usually be taken together safely
• Both medicines can lower blood pressure slightly; your prescriber checks your heart health during consultation
• Continue taking aspirin as prescribed; do not stop without medical advice
• Report unusual bruising, bleeding, chest pain, or erections lasting over four hours immediately
• Declare all medicines during your consultation to ensure safe prescribing

What is tadalafil and aspirin used for?

Tadalafil is a prescription medicine used to treat erectile dysfunction (ED) in men [4]. It belongs to a group of medicines called PDE5 inhibitors, which work by relaxing blood vessels in the penis, allowing increased blood flow when you are sexually aroused. Tadalafil is available on-demand (10mg or 20mg taken at least 30 minutes before sex, with effects lasting up to 36 hours) or as a daily low dose (2.5mg or 5mg) [4]. It requires sexual stimulation to work and does not cure ED.

Aspirin is an antiplatelet medicine that reduces the ability of blood cells called platelets to stick together and form clots. Many people take low-dose aspirin (usually 75mg daily) to help prevent heart attacks and strokes, especially if they have cardiovascular disease, diabetes, or other risk factors. Higher doses are sometimes used for pain relief or inflammation. Because both tadalafil and aspirin affect the cardiovascular system in different ways, understanding how they work together is important for safe use.

How do tadalafil and aspirin interact in the body?

Tadalafil and aspirin do not have a significant direct drug interaction at the level of how they are processed in the body [4]. Aspirin does not interfere with how your liver breaks down tadalafil, and tadalafil does not affect aspirin's antiplatelet action. This means the two medicines can generally be taken together without one making the other more or less effective.

However, both medicines can have effects on your cardiovascular system that may add together. Tadalafil can cause a modest drop in blood pressure, particularly when you first start taking it or when standing up quickly [4]. Aspirin, especially at higher doses, can also contribute to blood pressure changes. Additionally, tadalafil has a mild antiplatelet effect of its own, which means it slightly reduces blood clotting. When combined with aspirin's stronger antiplatelet action, there is a theoretical increase in bleeding risk, though this is usually not clinically significant at normal doses.

What happens in plain English

Think of tadalafil as opening up blood vessels to improve blood flow where it's needed, while aspirin makes your blood slightly less 'sticky' to prevent unwanted clots. Neither medicine stops the other from working, but both can lower blood pressure a little and affect bleeding. For most men on low-dose aspirin for heart protection, this combination is well tolerated and safe when prescribed appropriately. Your prescriber checks your full medical picture to ensure the benefits outweigh any small added risks.

At a glance

What does your prescriber check before prescribing tadalafil with aspirin?

During your online consultation at Cured Pharmacy, the UK-registered prescriber will review your complete medical history and all current medicines, including aspirin [2]. They will check why you are taking aspirin (for example, previous heart attack, stroke prevention, or other cardiovascular conditions) and the dose you take. This helps them assess your overall cardiovascular health and whether sexual activity is safe for you.

The prescriber will also ask about your blood pressure, any history of bleeding disorders, stomach ulcers, or recent surgery, as these can be relevant when taking both medicines together [4]. They will ensure you are not taking any medicines that must never be combined with tadalafil, such as nitrates (GTN spray, isosorbide mononitrate), nicorandil, riociguat, or recreational drugs called 'poppers' [4]. If you take other blood pressure medicines or alpha-blockers (such as tamsulosin or doxazosin), the prescriber will consider starting you on a lower dose of tadalafil to minimise the risk of dizziness or fainting.

Why cardiovascular health matters

If you are taking aspirin for heart disease, it means your cardiovascular system needs extra care. ED itself can be an early warning sign of heart or blood vessel problems [1]. The prescriber needs to confirm that your heart is healthy enough for sexual activity, which can be as demanding as moderate exercise. This is not about the interaction between tadalafil and aspirin specifically, but about ensuring the overall safety of ED treatment in the context of your heart health.

Practical advice for taking tadalafil and aspirin together

If your prescriber approves tadalafil for you and you are already taking aspirin, continue taking your aspirin exactly as prescribed by your doctor [4]. Do not stop or change your aspirin dose without medical advice, as it is usually prescribed for important heart or stroke prevention. Take tadalafil as directed: on-demand tablets (10mg or 20mg) should be taken at least 30 minutes before sexual activity, while daily tablets (2.5mg or 5mg) are taken at the same time each day, regardless of when you plan to have sex.

Be aware of how you feel when you first start tadalafil, especially if you also take other blood pressure medicines. Stand up slowly from sitting or lying down to reduce the risk of dizziness [4]. Avoid heavy alcohol, which can worsen ED, increase the risk of low blood pressure, and may irritate your stomach if you are on aspirin. If you experience any unusual bruising, bleeding (such as nosebleeds or blood in urine or stools), or prolonged bleeding from cuts, contact your GP, as this may indicate an increased bleeding tendency.

Keep all your healthcare providers informed. If you see your GP, a hospital specialist, or a dentist, mention that you take both tadalafil and aspirin. If you are prescribed any new medicine, check with your pharmacist or prescriber that it is safe to take with your current treatments. Never take another PDE5 inhibitor (such as sildenafil or vardenafil) at the same time as tadalafil.

Warning signs and when to seek help with tadalafil and aspirin

Most men taking tadalafil and aspirin together do not experience serious problems, but it is important to know the warning signs that need urgent attention [4]. If you develop chest pain or discomfort during or after sexual activity, stop what you are doing and seek immediate medical help. Do not take GTN or any nitrate medicine if you have used tadalafil, as this combination can cause a dangerous drop in blood pressure.

Seek urgent medical help if you have an erection lasting more than four hours (priapism), even if it is not painful. This is a medical emergency that requires treatment to prevent permanent damage [4]. Similarly, sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing (sometimes with ringing in the ears or dizziness), requires immediate medical attention, as these are rare but serious side effects of PDE5 inhibitors.

If you notice signs of unusual bleeding—such as vomiting blood, black tarry stools, severe bruising, or bleeding that will not stop—contact your GP urgently or go to A&E, especially if you are on aspirin [4]. While the combination of tadalafil and aspirin does not usually cause significant bleeding problems, any new or concerning symptoms should be checked promptly.

Common side effects to expect

Common side effects of tadalafil include headache, indigestion, back pain, muscle aches, flushing, and a stuffy or runny nose [4]. These are usually mild and temporary. Aspirin can cause stomach upset or indigestion in some people. If you experience troublesome side effects from either medicine, speak to your pharmacist or prescriber for advice, but do not stop taking aspirin without consulting your doctor, as it is often prescribed for important medical reasons.

Other medicines and considerations with tadalafil and aspirin

Beyond aspirin, your prescriber will check all your other medicines during the consultation [2][4]. Some medicines can significantly affect how tadalafil works or increase the risk of side effects. For example, potent CYP3A4 inhibitors (such as ritonavir, cobicistat, ketoconazole, itraconazole, or clarithromycin) can raise tadalafil levels in your blood, requiring a lower dose. Conversely, CYP3A4 inducers (such as rifampicin, carbamazepine, phenytoin, or St John's wort) can reduce tadalafil's effectiveness.

If you take alpha-blockers for prostate symptoms (such as tamsulosin, doxazosin, or alfuzosin), you should be stable on that medicine before starting tadalafil, and your prescriber will usually start you on the lowest dose to minimise the risk of low blood pressure or dizziness [4]. Other blood pressure medicines can also add to tadalafil's blood-pressure-lowering effect, but this is usually manageable with careful monitoring and dose adjustment.

Grapefruit juice can increase tadalafil levels and should be avoided or limited [4]. If you take any other antiplatelet or anticoagulant medicines (such as clopidogrel, warfarin, or direct oral anticoagulants like apixaban or rivaroxaban) alongside aspirin, your prescriber will carefully assess your bleeding risk. Always declare every medicine, supplement, and herbal remedy you take during your consultation, even if you think it is unimportant.

When to get urgent help

• Chest pain or discomfort during or after sex (do not take nitrates if you have used tadalafil)
• Erection lasting more than four hours, even if not painful (priapism)
• Sudden loss of vision in one or both eyes
• Sudden decrease or loss of hearing, possibly with ringing or dizziness
• Vomiting blood, black tarry stools, or severe bleeding that will not stop

Call 999 or go to A&E in an emergency, or contact NHS 111 for urgent advice.