Tadalafil and COVID: Is It Safe?

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Tadalafil and COVID: Is It Safe to Use During or After Infection?

Published: 8 November 2026

Many men wonder whether tadalafil and COVID are compatible—specifically, whether it's safe to take tadalafil (Cialis) during a COVID-19 infection, after recovery, or alongside COVID treatments. Tadalafil itself is not known to worsen COVID-19, but certain COVID treatments, particularly Paxlovid (nirmatrelvir/ritonavir), can significantly raise tadalafil levels in the blood and increase the risk of side effects [4]. If you are currently taking COVID medication or recovering from infection, it's essential to discuss tadalafil use with a healthcare professional during your consultation to ensure it's safe for your individual circumstances.

Does tadalafil interact with COVID-19 treatments?

The most important interaction to be aware of is between tadalafil and Paxlovid, a common antiviral treatment for COVID-19. Paxlovid contains ritonavir, a potent CYP3A4 inhibitor that slows the breakdown of tadalafil in your body, leading to much higher levels of the drug in your bloodstream [4]. This increases the risk of side effects such as headache, flushing, dizziness, and dangerously low blood pressure.

If you are prescribed Paxlovid, your doctor will typically advise you to stop taking tadalafil temporarily while you complete the course of antiviral treatment. The same caution applies to other potent CYP3A4 inhibitors, including certain antifungal medicines (ketoconazole, itraconazole) and some antibiotics (clarithromycin) [4]. Your prescriber will review all your current medications during the consultation to check for interactions.

Other COVID treatments, such as molnupiravir or remdesivir, are not known to have significant interactions with tadalafil. However, always inform your doctor or pharmacist about every medicine you are taking, including over-the-counter products and supplements, to ensure safe use.

Can I take tadalafil if I currently have COVID-19?

There is no evidence that tadalafil makes COVID-19 infection worse or interferes with your body's ability to fight the virus. However, if you are unwell with COVID-19—experiencing fever, fatigue, breathlessness, or other symptoms—sexual activity may not be advisable simply because your body needs rest to recover [1].

Tadalafil works by relaxing blood vessels, which can lower blood pressure slightly. If COVID-19 has already made you feel dizzy, weak, or dehydrated, taking tadalafil could add to these symptoms. It's sensible to wait until you feel well enough for physical activity before resuming tadalafil or any erectile dysfunction treatment.

If you are taking antiviral medication such as Paxlovid, you must not take tadalafil at the same time due to the serious drug interaction described above. Always check with a healthcare professional if you are unsure whether it is safe to continue or restart tadalafil during an active infection.

When is it safe to restart tadalafil after COVID?

Most people can safely restart tadalafil once they have recovered from COVID-19 and are no longer taking antiviral treatments. If you were prescribed Paxlovid, wait until you have finished the full course (usually five days) and the drug has cleared your system—typically within a few days after the last dose [12].

If COVID-19 has left you with ongoing symptoms such as fatigue, breathlessness, or chest discomfort (sometimes called 'long COVID'), speak to your GP before resuming tadalafil. These symptoms may indicate that your cardiovascular system needs further assessment, and your doctor can advise whether it is safe for you to engage in sexual activity and use ED medication [1][2].

Does COVID-19 cause erectile dysfunction?

Emerging research suggests that COVID-19 may contribute to erectile dysfunction in some men, both during the acute illness and in the months following recovery. Possible mechanisms include damage to the lining of blood vessels (endothelial dysfunction), reduced blood flow, inflammation, and psychological stress associated with the illness [1][2].

COVID-19 can also worsen existing risk factors for ED, such as diabetes, high blood pressure, and obesity. If you have noticed new or worsening erection problems since having COVID-19, it's important to see your GP. Erectile dysfunction can be an early warning sign of cardiovascular disease, and a medical assessment can help identify any underlying health issues that need treatment [1][2].

Tadalafil and other PDE5 inhibitors such as sildenafil (Viagra) can be effective treatments for ED related to COVID-19, provided there are no contraindications. Your prescriber will review your medical history, current medications, and overall health during the consultation to determine the most appropriate treatment for you.

What are the risks of taking tadalafil and COVID medications together?

The main risk is a dangerous drop in blood pressure if tadalafil is combined with Paxlovid or other potent CYP3A4 inhibitors. Ritonavil in Paxlovid can increase tadalafil levels several-fold, leading to prolonged and severe side effects including dizziness, fainting, headache, visual disturbances, and priapism (a painful erection lasting more than four hours) [4][12].

Even a single dose of tadalafil taken while on Paxlovid can cause problems, so it is essential to stop tadalafil before starting antiviral treatment and not restart it until the Paxlovid course is complete and cleared from your body. Your prescriber or pharmacist will give you clear instructions on when it is safe to resume.

If you are taking other medicines for high blood pressure, heart conditions, or prostate problems (such as alpha-blockers like tamsulosin or doxazosin), the combination with tadalafil requires careful monitoring. Always declare all your current medications during the online consultation so that the prescriber can check for interactions and adjust doses if necessary [4].

What should I do if I've already taken tadalafil with Paxlovid?

If you have accidentally taken tadalafil while on Paxlovid, monitor yourself closely for signs of low blood pressure: dizziness, lightheadedness, fainting, rapid heartbeat, or visual changes. Sit or lie down if you feel unwell, and avoid driving or operating machinery.

If you develop severe symptoms—such as chest pain, difficulty breathing, a prolonged erection lasting more than four hours, or sudden loss of vision or hearing—seek urgent medical help by calling 999 or going to A&E immediately. Inform the healthcare team that you have taken both medicines so they can provide appropriate treatment.

Tadalafil and COVID: what does the research say?

While large-scale clinical trials specifically examining tadalafil and COVID outcomes are limited, some early studies have explored whether PDE5 inhibitors might have a role in managing COVID-19 complications. Tadalafil's ability to relax blood vessels and improve blood flow has led researchers to investigate whether it could help reduce lung inflammation or improve oxygen levels in hospitalised patients.

However, these studies are preliminary, and tadalafil is not approved or recommended as a treatment for COVID-19 itself. The primary use of tadalafil remains the treatment of erectile dysfunction and, in some cases, benign prostatic hyperplasia and pulmonary arterial hypertension [4]. If you are interested in tadalafil for ED, the decision should be based on your symptoms, medical history, and suitability for the medication, not on any potential COVID-related benefits.

What is clear is that COVID-19 can have lasting effects on vascular health, and men who experience new ED after infection should seek medical advice. Tadalafil may be an effective option once any acute illness has resolved and it is safe to resume treatment [1][2].

How to use tadalafil safely after COVID-19 recovery

Once you have fully recovered from COVID-19 and are no longer taking antiviral medication, you can usually resume tadalafil safely. Tadalafil is available in two forms: on-demand tablets (10 mg or 20 mg taken at least 30 minutes before sexual activity, with effects lasting up to 36 hours) and daily low-dose tablets (2.5 mg or 5 mg taken once a day) [4]. Your prescriber will recommend the most suitable option based on your needs and lifestyle.

Start with the lowest effective dose, especially if you are taking other medications or have underlying health conditions. Tadalafil requires sexual stimulation to work and does not cause spontaneous erections. Avoid taking it with alcohol in large amounts, as this can increase the risk of dizziness and reduce the effectiveness of the treatment [4].

At Cured Pharmacy, all tadalafil prescriptions are issued following an online consultation reviewed by a UK-registered prescriber. You will be asked about your medical history, current medications (including any recent COVID treatments), and overall health to ensure tadalafil is safe and appropriate for you. Tadalafil is available from £7.95, or £6.36 for first orders with code Ednew.

When to see your GP about ED after COVID

If you have developed erectile dysfunction for the first time after having COVID-19, or if existing ED has become significantly worse, book an appointment with your GP. ED can be an early sign of cardiovascular disease, diabetes, or other health conditions that may need investigation and treatment [1][2].

Your GP can arrange blood tests to check cholesterol, blood sugar, and hormone levels, and assess your heart health. They can also review any medications you are taking that might contribute to ED and discuss lifestyle changes—such as losing weight, stopping smoking, reducing alcohol, and increasing physical activity—that can improve both your general health and erectile function [1][2].

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 8 November 2026]
2. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 8 November 2026]
3. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 8 November 2026]
4. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 8 November 2026]

Information on this page is for educational purposes only and is not medical advice. Prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting or changing any medication.

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