Tadalafil, known by the brand name Cialis, is a widely used prescription medication that treats erectile dysfunction (ED), which refers to difficulty achieving or maintaining an erection. 

If you’re experiencing ED, you may consider medication as a treatment option, such as sildenafil (more commonly known by one of its brand names Viagra) or tadalafil. These are two of the most commonly prescribed medical treatments for ED in the UK, where 41.5% of men report experiencing ED on some level. [1]

Globally, ED prevalence ranges from 3% to 76.5%, with estimates projecting that 322 million men will experience ED at some point in their lifetime. [2] 

Understanding the common side effects is essential for the safe use of tadalafil. While many people tolerate the medication well and achieve the desired results, some may experience side effects ranging from mild to severe. However, severe side effects occur only in a small number of cases.

This guide explains what to expect when taking tadalafil and what the potential side effects are. It will help you determine if this medication is the right choice and when to seek medical advice, should you experience any side effects. Always consult a UK healthcare professional before starting any medication.

How tadalafil works 

Tadalafil belongs to a class of drugs known as PDE5 inhibitors, along with vardenafil (better known by the brand name Levitra) and sildenafil. It works by blocking the enzyme phosphodiesterase type 5 (PDE5), which breaks down a substance called cyclic guanosine monophosphate (cGMP).

Higher levels of this substance allow smooth muscle lining blood vessels in the penis to relax, improving blood flow and making it easier to achieve and maintain an erection. [3] 

Uses of tadalafil

Treatment for erectile dysfunction 

The Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom has approved tadalafil for treating both ED and Benign Prostatic Hyperplasia (BPH), which is an enlarged prostate. [4]

Daily vs on-demand dosing

Tadalafil is available in two dosing options:

• Daily dosing (2.5mg or 5mg): Taken once daily, this lower-dose option allows you to maintain spontaneity in sexual activity, as the medication remains active in the system continuously.
• On-demand dosing (10mg or 20mg): Taken at least 30 minutes before sexual activity, this option provides flexibility but requires planning ahead. The effects can last up to 36 hours, earning tadalafil the nickname “the weekend pill.”

Treatment for benign prostatic hyperplasia (BPH)

You may also be prescribed Tadalafil if you’re suffering from BPH. The medication improves blood flow to specific areas of the body, including the penis, helping you achieve and maintain an erection. 

By relaxing the smooth muscle in the bladder and prostate, tadalafil helps improve urinary flow and reduces symptoms associated with BPH. Unlike some other BPH medications, tadalafil does not significantly lower blood pressure, making it a preferred option for those who cannot tolerate other treatments.

It also relaxes muscles in the bladder and prostate, easing the urinary symptoms associated with BPH, such as frequent urination, weak urine stream, and difficulty starting or stopping urination. [5]

Sexual activity and heart health

• Sexual activity increases heart rate and blood pressure, which can be risky for individuals with heart conditions.
• Those with cardiovascular disease should consult their doctor before using tadalafil, as physical exertion during sex may cause chest pain or shortness of breath.
• If chest pain or dizziness occurs during sex, medical help should be sought immediately. [6]

Arterial hypertension

• Tadalafil is occasionally prescribed for arterial hypertension, a condition where blood pressure in the arteries leading to the lungs is abnormally high. Known as pulmonary arterial hypertension (PAH), this condition can put excess strain on the heart and lungs, making it harder to breathe during physical activity. [7]
• For individuals with a history of arterial hypertension, tadalafil can help relax blood vessels, improving circulation and reducing strain on the heart. However, those taking medication for pulmonary arterial hypertension should consult a healthcare professional before combining treatments, as interactions can lead to complications such as dangerously low blood pressure. [8]
• If you experience chest pain, dizziness, or difficulty breathing while taking tadalafil, seek immediate medical attention.

Common tadalafil side effects

While tadalafil is generally well-tolerated, some users may experience mild to moderate side effects. Here are some of the most common:

Headaches

Headaches are one of the most frequently reported side effects of tadalafil. [9] This occurs due to the widening of blood vessels, which can cause temporary changes in blood pressure.

• How common is it? At least 1 in 100 people will experience headaches while taking tadalafil. [10] 
• How to manage it? Staying hydrated, avoiding excessive alcohol, and taking paracetamol can help relieve symptoms. If headaches persist, consulting a healthcare provider is recommended.

Muscle pain

You can experience muscle aches or back pain after taking tadalafil, as some users report this. [11] This happens because the drug affects smooth muscle relaxation, which can lead to mild discomfort in the lower back or legs.

• Why does it occur? Increased blood flow and vasodilation may trigger muscle sensitivity. Increased blood flow and vasodilation may trigger muscle sensitivity.
• Management tips: Light stretching, staying hydrated, and using over-the-counter pain relievers can help reduce discomfort. [12] Light stretching, staying hydrated, and using over-the-counter pain relievers can help reduce discomfort.

Indigestion

Tadalafil may cause mild stomach discomfort or acid reflux in some individuals. 

What causes it? The drug relaxes smooth muscle, including those in the digestive tract, potentially leading to indigestion or bloating. [13]

How to minimise discomfort? Taking Tadalafil with food, avoiding spicy or acidic meals, and drinking plenty of water can help ease symptoms. [14]

Chest pain

• Tadalafil lowers blood pressure, which can lead to chest pain, especially in individuals with pre-existing heart conditions. [15]
• If chest pain occurs during sexual activity, the medication should be stopped, and medical attention should be sought immediately.
• If you’re taking nitrates for angina, you should not use tadalafil due to the risk of dangerously low blood pressure. [16]

Flushing

Flushing is a common side effect of tadalafil and is caused by the widening of blood vessels (vasodilation), which increases blood flow near the surface of the skin. This can result in a warm or red appearance, typically on the face, neck, or chest. The effect is usually mild and short-lived, but may feel uncomfortable for some users. [17]

Staying cool, avoiding hot drinks or spicy foods, and drinking plenty of water can help manage this symptom. 

Nasal congestion

Users of tadalafil report nasal congestion or a stuffy nose as one of the common side effects of the drug. Nasal congestion occurs due to tadalafil’s effect on blood vessels, leading to temporary swelling of nasal tissues.

This can cause mild breathing difficulties, especially in individuals with pre-existing sinus issues. [18] Over-the-counter decongestants and steam inhalation may help relieve this symptom.

Treatment for benign prostatic hyperplasia (BPH)

Benign prostatic hyperplasia (BPH) can affect many men as they age, causing uncomfortable urinary symptoms. These include frequent urination, urgency, weak urine flow, and difficulty starting or stopping urination.

In the UK, doctors prescribe tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor, to treat BPH. Unlike some other BPH medications, tadalafil does not significantly lower blood pressure. [19] This means it could be a good option for you if you cannot tolerate other treatments well.

Rare and serious side effects of tadalafil

Priapism

Serious side effects from tadalafil are rare but can occur. One side effect is priapism, a prolonged and often painful erection unrelated to sexual stimulation. If untreated, this condition can cause severe discomfort, ED, and permanent tissue damage. However, priapism occurs in less than 1 in 1000 cases linked to tadalafil. [20]

Understanding priapism helps you recognize when to seek medical care. There are two main types: ischemic (low-flow) and nonischemic (high-flow).

Ischemic priapism is more common and serious. It occurs when blood gets trapped in the penis due to issues with smooth muscle contraction. This can lead to oxygen loss and tissue damage, so it requires urgent medical attention. Signs include an erection lasting over four hours, a firm shaft with a softer tip, and increasing pain. A related form, stuttering priapism, causes repeated, painful erections — especially in people with sickle cell disease.

Nonischemic priapism is usually caused by trauma and results from poor arterial blood flow regulation. It’s less painful and not an emergency, since oxygen supply isn’t fully blocked. Symptoms include a prolonged but less rigid erection with little or no pain. Treatment focuses on managing the underlying cause, but you should still consult a healthcare provider.

Sudden hearing loss

While hearing-related side effects from tadalafil are rare, some users have reported a sudden decrease or loss of hearing in one or both ears. This condition, known as sudden sensorineural hearing loss (SSNHL), may be accompanied by tinnitus (ringing in the ears) or dizziness. This side effect can also occur with similar medications, including sildenafil. 

The exact cause of this hearing impairment is unclear, but experts believe it may be linked to the effect tadalafil has on blood flow and nerve function in the inner ear. Anyone experiencing a sudden decrease in hearing while taking tadalafil should discontinue use immediately and seek urgent medical advice. 

In some cases, hearing loss occurred within 24 hours of ingestion and was accompanied by symptoms such as tinnitus (ringing in the ears) and aural fullness. The exact cause is unclear, but recognising symptoms early is crucial. [21]

Signs to look out for:

• Rapid onset of hearing loss in one or both ears 
• Ringing or buzzing sounds 
• A feeling of fullness in the ear 

Immediate steps to take:

If you experience any of these symptoms while taking tadalafil, stop using it immediately and seek urgent medical attention. Early intervention may improve the likelihood of recovery. 

Individuals with pre-existing ear conditions, such as Ménière’s disease, may be at greater risk. While most cases of hearing loss are temporary, prompt medical attention is crucial to prevent permanent damage. If you have a history of ear disorders or frequently experience hearing fluctuations, consult your doctor before using tadalafil. [22]

Blurred vision

Some tadalafil users have reported episodes of blurred vision, difficulty distinguishing colours, or even a sudden decrease in eyesight. This is often linked to non-arteritic anterior ischemic optic neuropathy (NAION), a condition that affects blood flow to the optic nerve. 

While rare, those with diabetes, high cholesterol, or pre-existing eye conditions may be at greater risk of developing vision-related side effects.

Symptoms such as blurred vision, difficulty adjusting to bright light, a sudden partial loss of vision or severe vision loss should not be ignored. If you experience any sudden decrease in your ability to see clearly or severe vision loss, stop using tadalafil and seek medical advice immediately.

If you do experience these side effects, eye health professionals may conduct tests to determine whether tadalafil is safe for your continued use. Regular eye exams can help detect early warning signs of complications associated with ED medications. 

Loss of vision

• While rare, some users of tadalafil have reported sudden vision loss due to non-arteritic anterior ischemic optic neuropathy.
• Symptoms include blurry vision, difficulty distinguishing between colours, or complete vision loss in one or both eyes.
• Anyone experiencing these symptoms should stop taking the medication immediately and seek urgent medical advice. [23]

Allergic reactions

Although uncommon, allergic reactions to tadalafil can occur. Recognising symptoms so you can catch it early is vital to safe use of the medication.

Symptoms of an allergic reaction to tadalafil include:

• Skin rash or itching 
• Swelling of the face, lips, tongue, or throat 
• Difficulty breathing 

Importance of medical attention:

If you notice any signs of an allergic reaction, stop taking tadalafil and seek medical help immediately. Severe reactions, such as anaphylaxis, require emergency treatment. [24]

Precautions before using tadalafil

Before starting tadalafil, it is crucial to discuss your medical history with your doctor to ensure it is safe for you to take.

Medical history considerations:

Heart conditions: Tadalafil can cause serious side effects in people with heart disease, particularly those who have had a heart attack or stroke in the past six months. [25] 

Blood pressure issues: High or low blood pressure may increase the risk of side effects, including dizziness and fainting. [26] 

Eye problems: Those with conditions such as retinitis pigmentosa or a history of sudden vision loss should speak to their doctor before using tadalafil. [27] 

Kidney or liver disease: Impaired kidney or liver function can affect how the body processes tadalafil, potentially leading to increased side effects. [28]

Current medications and interactions

Tadalafil can interact with various medications, altering its effectiveness or increasing side effects.

Nitrates: Combining tadalafil with nitrate medications (commonly used for angina) can cause a severe drop in blood pressure, which can be life-threatening. [29] You must never use tadalafil alongside nitrates.

Alpha-blockers: Used for prostate problems or high blood pressure, these medications can also lead to dangerously low blood pressure when taken with tadalafil. 

Antifungal and antibiotic medications: Certain antifungals and antibiotics can increase Tadalafil levels in the blood, heightening the risk of side effects. 

Other ED medications: Taking multiple ED treatments at the same time is not recommended due to the increased risk of side effects. [30]

Dietary restrictions

Certain foods and beverages can affect how tadalafil works in the body.

Alcohol: Drinking excessive alcohol while taking tadalafil may increase the risk of tadalafil side effects, including dizziness, headache, and low blood pressure. 

Grapefruit products: Grapefruit can interfere with how tadalafil is metabolised, leading to increased side effects. [31]

Managing side effects of tadalafil 

If you do experience side effects while taking tadalafil, understanding how to manage them safely can help you continue treatment with confidence.

Over the counter remedies

Mild side effects of tadalafil can often be managed with simple at-home treatments. Here are some common side effects and safe ways to alleviate them:

• Headaches – Staying well-hydrated and using over-the-counter pain relievers such as paracetamol or ibuprofen can help reduce headaches.
• Indigestion or acid reflux – Taking Tadalafil with food and using antacids or acid reducers (like omeprazole) may ease digestive discomfort.
• Flushing (redness and warmth in the face) – Cooling down with a cold drink or using a fan can help alleviate this temporary side effect. 
• Blocked or runny nose – Decongestants such as pseudoephedrine can provide relief, but check with a pharmacist to ensure they are safe for you. [32]

While these remedies can be helpful, always consult a pharmacist or GP if side effects persist or worsen.

When to contact a healthcare provider

Although rare, some side effects of Tadalafil require immediate medical attention. Seek urgent medical help if you experience:

• Chest pain or severe dizziness – This may indicate a serious cardiovascular reaction. 
• Sudden vision or hearing loss – Discontinue use and see a doctor immediately if you notice these symptoms. 
• Priapism (painful, prolonged erection lasting over 4 hours) – This is a medical emergency that requires urgent treatment to prevent permanent damage.
• Severe allergic reaction (anaphylaxis) – If you experience swelling of the face, lips, or throat, difficulty breathing, or a severe rash, call emergency services immediately. 

If you are unsure whether a side effect requires medical attention, contact your GP or pharmacist for advice.

Comparing tadalafil to other treatments

Tadalafil is just one of several treatments available for ED. Understanding how it compares to alternatives can help you make an informed decision.

Tadalafil vs. sildenafil 

• While both medications are effective, tadalafil’s 36-hour duration provides more flexibility, whereas sildenafil lasts 4–6 hours and requires more precise timing.
• Both medications have similar side effects, but tadalafil is less likely to cause vision disturbances. Sildenafil is slightly more likely to cause vision-related side effects, such as blue-tinged vision, whereas tadalafil is more associated with muscle aches. 
• Onset time – Sildenafil typically works within 30–60 minutes, whereas tadalafil can take 30 minutes to 2 hours. [33]

Tadalafil vs. Vardenafil (Levitra) and Avanafil (Spedra)

• Vardenafil and avanafil work similarly to sildenafil but have shorter durations than tadalafil.
• Avanafil has the fastest onset (15 minutes), making it ideal for last-minute planning, whereas tadalafil is preferred for long-lasting effects. 

Other ED Medications

• Vardenafil (Levitra) – Works similarly to sildenafil but may have a slightly lower risk of side effects in some users. Generally, the potential side effects are very similar to sildenafil.
• Avanafil (Spedra) – Acts faster than sildenafil (within 15–30 minutes) but has a shorter duration of action 
• Alprostadil (Caverject, Muse, Viridal Duo) – Available as injections or urethral suppositories for those who do not respond to oral medications [34].

Seek advice from a medical professional to help determine which treatment best suits your needs.

Importance of communication with healthcare providers

Open and ongoing communication with your doctor is key to ensuring safe and effective treatment.

Discussing concerns and side effects

If you experience any side effects or have concerns about tadalafil, do not hesitate to discuss them with your doctor. Adjustments to your dosage or an alternative medication may be recommended based on your individual response.

Regular monitoring and follow-up

Regular check-ups allow your doctor to monitor your overall health and ensure that tadalafil remains safe and effective for you. This is particularly important if you have underlying conditions such as heart disease or high blood pressure.

Making an informed decision on the right ED medication for you means understanding the potential side effects and when to see a doctor. Choosing the right ED, whether its tadalafil or another option, depends on individual health concerns, lifestyle, and personal preference. 

If you experience any of these side effects, whether its chest pain, vision changes, or severe nasal congestion, seek medical advice immediately. Remember to speak with a healthcare professional to determine whether tadalafil or another ED medication is best for you. 

Find out what treatment is suitable for you on our website.

References

1. Epidemiology of ED» Sexual Medicine» BUMC [Internet]. Bu.edu. 2020. Available from: https://www.bumc.bu.edu/sexualmedicine/physicianinformation/epidemiology-of-ed/
2. Kessler A, Sollie S, Challacombe B, Briggs K, Van Hemelrijck M. The global prevalence of erectile dysfunction: a review. BJU International. 2019 Jul 2;124(4):587–99.
3. Chen CY, Hwang TL. Tadalafil ☆. Elsevier eBooks [Internet]. 2018 Jan 1 [cited 2024 Oct 28]; Available from: https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/tadalafil
4. European Commission approves Cialis® (tadalafil) tablets for the treatment of the signs and symptoms of benign prostatic hyperplasia | Eli Lilly and Company [Internet]. Eli Lilly and Company. 2024 [cited 2025 Mar 27]. Available from: https://investor.lilly.com/news-releases/news-release-details/european-commission-approves-cialisr-tadalafil-tablets-treatment
5. Fahmy G, Hess J. Tadalafil [Internet]. PubMed. Treasure Island (FL): StatPearls Publishing; 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK603743/
6. Are erectile dysfunction pills safe for men with heart disease? – Harvard Health [Internet]. Harvard Health. 2005 [cited 2025 Mar 27]. Available from: https://www.health.harvard.edu/mens-health/are-erectile-dysfunction-pills-safe-for-men-with-heart-disease?utm_source=chatgpt.com
7. Galiè N, Brundage BH, Ghofrani HA, Oudiz RJ, Simonneau G, Safdar Z, et al. Tadalafil Therapy for Pulmonary Arterial Hypertension. Circulation. 2009 Jun 9;119(22):2894–903.
8. Kloner RA, Kostis JB, McGraw TP, Qiu C, Gupta A. Analysis of integrated clinical safety data of tadalafil in patients receiving concomitant antihypertensive medications. The Journal of Clinical Hypertension. 2022 Jan 31;24(2):167–78.
9. Fahmy G, Hess J. Tadalafil [Internet]. PubMed. Treasure Island (FL): StatPearls Publishing; 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK603743/
10. Hartmut Porst, Harin Padma-Nathan, Giuliano F, Anglin G, Varanese L, Rosen RC. Efficacy of tadalafil for the treatment of erectile dysfunction at 24 and 36 hours after dosing: a randomized controlled trial. Urology. 2003 Jul 1;62(1):121–5.
11. Seftel AD, Farber J, Fletcher J, Deeley MC, Elion-Mboussa A, Hoover A, et al. A three-part study to investigate the incidence and potential etiologies of tadalafil-associated back pain or myalgia. International Journal of Impotence Research [Internet]. 2005 Sep 1 [cited 2021 Jul 30];17(5):455–61. Available from: https://www.nature.com/articles/3901374
12. https://www.facebook.com/nhswebsite. Side effects of tadalafil [Internet]. nhs.uk. 2022. Available from: https://www.nhs.uk/medicines/tadalafil/side-effects-of-tadalafil/
13. Carbone F, Tack J. The effect of sildenafil on gastric motility and satiation in healthy controls. United European Gastroenterology Journal. 2018 Jul;6(6):846–54.
14. https://www.facebook.com/nhswebsite. Side effects of tadalafil [Internet]. nhs.uk. 2022. Available from: https://www.nhs.uk/medicines/tadalafil/side-effects-of-tadalafil/
15. Kloner RA, Mitchell M, Emmick JT. Cardiovascular effects of tadalafil. The American Journal of Cardiology. 2003 Nov;92(9):37–46.
16. Brewer A. Cialis side effects: What you should know [Internet]. Medicalnewstoday.com. Medical News Today; 2021 [cited 2025 Mar 27]. Available from: https://www.medicalnewstoday.com/articles/drugs-cialis-side-effects
17. Eardley I, Gentile V, Edoardo Austoni, Hackett G, Lembo D, Wang CA, et al. Efficacy and safety of tadalafil in a Western European population of men with erectile dysfunction. 2004 Oct 1;94(6):871–7.
18. Fahmy G, Hess J. Tadalafil [Internet]. PubMed. Treasure Island (FL): StatPearls Publishing; 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK603743/
19. Hatzimouratidis K. A review of the use of tadalafil in the treatment of benign prostatic hyperplasia in men with and without erectile dysfunction. Therapeutic Advances in Urology. 2014 May 5;6(4):135–47.
20. Rezaee ME, Gross MS. Are We Overstating the Risk of Priapism With Oral Phosphodiesterase Type 5 Inhibitors? The Journal of Sexual Medicine. 2020 Aug;17(8):1579–82.
21. Wester JL, Ishiyama G, Karnezis S, Ishiyama A. Sudden hearing loss after cialis (tadalafil) use: A unique case of cochlear hydrops. The Laryngoscope. 2018 Sep 12;128(11):2615–8.
22. Zhang X, Xia L, Yang Q, Tang P. Phosphodiesterase type 5 inhibitors related hearing impairment: a real world study based on the FDA adverse event reporting system. Scientific Reports. 2024 Apr 28;14(1).
23. Medication E. Erectile Dysfunction (ED) Medication and Your Eyes and Vision [Internet]. American Academy of Ophthalmology. 2024. Available from: https://www.aao.org/eye-health/drugs/erectile-dysfunction-medication-your-eyes-vision
24. Tadalafil (Cialis, Adcirca, and others): Uses, Side Effects, Interactions, Pictures, Warnings & Dosing – WebMD [Internet]. Webmd.com. 2024 [cited 2025 Mar 27]. Available from: https://www.webmd.com/drugs/2/drug-77875/tadalafil-oral/details?
25. Kloner RA, Mitchell M, Emmick JT. Cardiovascular effects of tadalafil. The American Journal of Cardiology. 2003 Nov;92(9):37–46.
26. Brewer A. Cialis side effects: What you should know [Internet]. Medicalnewstoday.com. Medical News Today; 2021. Available from: https://www.medicalnewstoday.com/articles/drugs-cialis-side-effects
27. Tadalafil (Oral Route) Description and Brand Names – Mayo Clinic [Internet]. www.mayoclinic.org. Available from: https://www.mayoclinic.org/drugs-supplements/tadalafil-oral-route/description/drg-20067204
28. Tadalafil: MedlinePlus Drug Information [Internet]. medlineplus.gov. Available from: https://medlineplus.gov/druginfo/meds/a604008.html
29. Kloner RA, Hutter AM, Emmick JT, Mitchell MI, Denne J, Jackson G. Time course of the interaction between tadalafil and nitrates. Journal of the American College of Cardiology. 2003 Nov;42(10):1855–60.
30. Giuliano F, Kaplan SA, Cabanis MJ, Astruc B. Hemodynamic interaction study between the alpha1-blocker alfuzosin and the phosphodiesterase-5 inhibitor tadalafil in middle-aged healthy male subjects. Urology. 2006 Jun;67(6):1199–204.
31. Bailey DG, Dresser GK. Interactions Between Grapefruit Juice and Cardiovascular Drugs. American Journal of Cardiovascular Drugs [Internet]. 2004;4(5):281–97. Available from: https://link.springer.com/article/10.2165/00129784-200404050-00002
32. Tadalafil (Oral Route) Description and Brand Names – Mayo Clinic [Internet]. www.mayoclinic.org. Available from: https://www.mayoclinic.org/drugs-supplements/tadalafil-oral-route/description/drg-20067204
33. Choosing the Right Pill to Treat ED» Sexual Medicine» BUMC [Internet]. www.bumc.bu.edu. Available from: https://www.bumc.bu.edu/sexualmedicine/informationsessions/choosing-the-right-pill-to-treat-ed/
34. Evans JD, Hill SR. A comparison of the available phosphodiesterase-5 inhibitors in the treatment of erectile dysfunction: a focus on avanafil. Patient preference and adherence [Internet]. 2015 Aug 12;9:1159–64. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4542406/#:~:text=The%20terminal%20half%2Dlife%20of