Tadalafil Success Rate: How Well Does It Work?

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What Is the Tadalafil Success Rate for Erectile Dysfunction?

Published: 15 October 2026

The tadalafil success rate in clinical trials typically ranges from 60% to 80%, meaning that six to eight out of ten men experience improved erections sufficient for sexual intercourse [4]. Success depends on the dose used, the underlying cause of erectile dysfunction, and individual health factors such as diabetes or cardiovascular disease. Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor licensed in the UK for erectile dysfunction, available both as an on-demand treatment (10 mg or 20 mg taken at least 30 minutes before sex) and as a daily low-dose option (2.5 mg or 5 mg) [4].

How Effective Is Tadalafil in Clinical Trials?

Clinical trials have consistently demonstrated that tadalafil is highly effective for the majority of men with erectile dysfunction. In large-scale studies, around 60-80% of men reported improved ability to achieve and maintain erections firm enough for penetration and successful intercourse [4][8]. The response rate varies with dose: higher doses (20 mg) tend to produce better results than lower doses (10 mg), though individual response differs.

Tadalafil's unique feature is its long duration of action—up to 36 hours—which allows for greater spontaneity compared to shorter-acting PDE5 inhibitors [4]. This extended window does not mean a continuous erection; sexual stimulation is still required for the medicine to work. Men who do not respond to one PDE5 inhibitor may respond to another, so lack of success with sildenafil, for example, does not rule out a good response to tadalafil [2][8].

It is important to remember that tadalafil treats the symptom of erectile dysfunction but does not cure the underlying cause [1]. Conditions such as diabetes, high blood pressure, or cardiovascular disease can reduce the success rate, and addressing these through lifestyle changes or medical management often improves outcomes [2][10].

What Factors Affect the Tadalafil Success Rate?

Several factors influence how well tadalafil works for an individual. The underlying cause of erectile dysfunction plays a major role: men whose ED is related to psychological factors (such as performance anxiety or stress) often have higher success rates than those with severe vascular disease or nerve damage from diabetes [2][10]. Age also matters—older men and those with multiple health conditions may experience a lower response rate.

Lifestyle factors significantly impact effectiveness. Smoking, heavy alcohol consumption, obesity, and lack of physical activity all worsen erectile function and can reduce the benefit of tadalafil [1][2]. Conversely, men who stop smoking, lose weight, exercise regularly, and moderate alcohol intake often see improved results from the same dose. Adequate sexual stimulation and a relaxed environment are also essential, as tadalafil does not work without arousal [4].

Drug interactions can reduce tadalafil's effectiveness or increase the risk of side effects. Potent CYP3A4 inhibitors (such as ritonavir, ketoconazole, or clarithromycin) raise tadalafil levels in the blood, requiring dose adjustments, while CYP3A4 inducers (like rifampicin or St John's wort) can lower levels and reduce efficacy [4][12]. Always declare all current medicines during your consultation so the prescriber can check for interactions and recommend the safest, most effective dose.

Does Tadalafil Work for Everyone?

No medicine works for everyone, and tadalafil is no exception. Around 20-40% of men do not achieve a satisfactory response, particularly those with severe diabetes, extensive pelvic surgery (such as radical prostatectomy), significant nerve damage, or very low testosterone levels [2][8]. In these cases, alternative treatments—such as alprostadil injections, vacuum devices, or referral to a specialist—may be more appropriate [2][7]. If tadalafil does not work after several attempts at the maximum dose, speak to your GP or a specialist urologist for further assessment and alternative options.

How Does the Tadalafil Success Rate Compare to Other ED Treatments?

All four licensed oral PDE5 inhibitors in the UK—sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Spedra)—have broadly similar success rates, typically between 60% and 80% in clinical trials [2][8][11]. The main differences lie in how quickly they work and how long they last. Sildenafil and vardenafil take effect in about 30-60 minutes and last around 4-6 hours, while avanafil works faster (15-30 minutes) and tadalafil lasts much longer (up to 36 hours) [3][4][5][6].

Some men respond better to one PDE5 inhibitor than another, even though the success rates in trials are similar. This individual variation means that if one medicine does not work well, it is worth trying a different one [2]. Tadalafil's long duration makes it popular for men who prefer not to plan sex around a tablet, while sildenafil's shorter action suits those who want the effect to wear off more quickly.

For men who do not respond to oral tablets, other prescription options include alprostadil cream (Vitaros) applied to the tip of the penis or alprostadil injections (Caverject) into the side of the penis [7]. These have higher success rates in some cases but require more training and carry different side effects. Non-prescription options such as Eroxon gel (a topical medical device) are available but have lower reported success rates than PDE5 inhibitors [2]. Your prescriber or GP can discuss which treatment is most suitable based on your health, preferences, and response to previous therapies.

On-Demand vs Daily Tadalafil: Which Has a Better Success Rate?

Tadalafil is available in two dosing regimens: on-demand (10 mg or 20 mg taken at least 30 minutes before sex, with effects lasting up to 36 hours) and daily (2.5 mg or 5 mg taken once a day, regardless of sexual activity) [4]. Both regimens have similar overall success rates, but they suit different lifestyles and patterns of sexual activity.

On-demand tadalafil is ideal for men who have sex less than twice a week and prefer to take a tablet only when needed. The higher dose provides a strong, reliable effect for up to a day and a half, allowing flexibility and spontaneity [4]. Daily tadalafil, on the other hand, maintains a steady level of the medicine in the body, so you are ready for sex at any time without planning ahead. This can reduce performance pressure and is often preferred by men in stable relationships who have frequent sexual activity [2][4].

Clinical studies show that daily tadalafil can also improve lower urinary tract symptoms (such as difficulty urinating) in men with benign prostatic enlargement, offering a dual benefit [4]. However, daily dosing means taking a tablet every day, which may not suit everyone. Your prescriber will help you choose the regimen that best matches your needs, health status, and sexual activity patterns.

Can You Switch Between On-Demand and Daily Tadalafil?

Yes, you can switch between on-demand and daily tadalafil if your circumstances or preferences change, but you should do so under the guidance of your prescriber [4]. Switching regimens may require a dose adjustment and a review of your overall health and any other medicines you take. Never take both on-demand and daily tadalafil together, and do not combine tadalafil with another PDE5 inhibitor, as this increases the risk of serious side effects such as dangerously low blood pressure [4][12].

What Can You Do to Improve Your Tadalafil Success Rate?

Even if tadalafil works well, you can often improve your results further by addressing lifestyle and health factors. Stopping smoking is one of the most effective steps: smoking damages blood vessels and significantly worsens erectile function [1][2]. Losing weight if you are overweight, eating a balanced diet, and taking regular physical activity (at least 150 minutes of moderate exercise per week) all improve blood flow and overall cardiovascular health, which in turn supports better erections [2][10].

Moderating alcohol intake is also important. Heavy drinking can make erectile dysfunction worse and adds to the blood-pressure-lowering effect of tadalafil, increasing the risk of dizziness or fainting [4]. Limiting alcohol to a small amount (one or two units) when you plan to have sex is sensible. Managing stress, anxiety, and relationship issues—sometimes with the help of counselling or psychosexual therapy—can also make a significant difference, especially when psychological factors contribute to ED [1][2].

If you have diabetes, high blood pressure, or high cholesterol, working with your GP to optimise control of these conditions will improve your response to tadalafil and reduce your long-term cardiovascular risk [2][10]. Erectile dysfunction can be an early warning sign of heart disease, so treating it is not just about improving your sex life—it is also about protecting your overall health [1][10]. Always take tadalafil as prescribed, allow adequate time for it to work, and ensure you are sexually aroused; the medicine will not cause an erection on its own [4].

When Should You See a GP About Erectile Dysfunction?

If you are experiencing erectile dysfunction for the first time, or if it is getting worse, see your GP for a full assessment [1][2]. ED can be an early sign of underlying health problems such as diabetes, high blood pressure, or cardiovascular disease, and early diagnosis and treatment of these conditions can improve both your general health and your sexual function [1][10]. Your GP can also review your current medicines, as some (such as certain blood pressure tablets or antidepressants) can contribute to erectile problems and may be switched to alternatives [2]. If tadalafil or other PDE5 inhibitors do not work after several attempts, your GP can refer you to a specialist for further investigation and alternative treatments.

How to Access Tadalafil Through Cured Pharmacy

Tadalafil is a prescription-only medicine in the UK, which means it must be prescribed by a qualified healthcare professional after a clinical assessment [4][12]. At Cured Pharmacy (GPhC 9012511), you can request tadalafil through a confidential online consultation. You will be asked about your health, current medicines, and any conditions that might affect the safety or suitability of tadalafil. A UK-registered prescriber will review your answers and, if appropriate, issue a prescription. Your medicine is then dispensed by our pharmacy and delivered discreetly to your door.

We offer a range of tadalafil options to suit different needs and budgets. Generic tadalafil is available from £7.95 for a pack, or £6.36 for your first order with code Ednew. Tadalafil 20 mg (Teva) costs £9.99 (£7.99 with Ednew), and Avarante (tadalafil) 10 mg is £11.49 (£9.19 with Ednew). Branded Cialis is also available at £12.00 (£9.60 with Ednew). All prices include the consultation, prescription, and delivery.

If you are already taking other medicines—especially nitrates, alpha-blockers, or medicines that interact with tadalafil—you must declare them in your consultation [4][12]. The prescriber will check for interactions and advise whether tadalafil is safe for you, or recommend an alternative. Never take tadalafil if you use nitrates (such as GTN spray or isosorbide mononitrate), nicorandil, riociguat, or recreational drugs called poppers, as the combination can cause a dangerous drop in blood pressure [4][12]. If you have any questions or need advice, our pharmacy team is here to help.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 15 October 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 15 October 2026]
3. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 15 October 2026]
4. European Association of Urology. (n.d.). EAU Guidelines on Sexual and Reproductive Health. https://uroweb.org/guidelines/sexual-and-reproductive-health [accessed 15 October 2026]
5. Feldman, H. A., Goldstein, I., Hatzichristou, D. G., Krane, R. J., & McKinlay, J. B. (1994). Impotence and its medical and psychosocial correlates: Results of the Massachusetts Male Aging Study. Journal of Urology, 151(1), 54–61. https://pubmed.ncbi.nlm.nih.gov/8254833/ [accessed 15 October 2026]
6. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 15 October 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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