IIEF-5 Questionnaire: Assess Your ED Severity

Understanding the IIEF-5 Questionnaire for Erectile Dysfunction

Published: 17 October 2026

The IIEF-5 questionnaire (International Index of Erectile Function-5) is a clinically validated five-question assessment tool used worldwide to evaluate the severity of erectile dysfunction (ED). Developed by urologists and sexual health researchers, this brief questionnaire asks about confidence, firmness, maintenance of erections, satisfaction, and frequency of successful intercourse over the past four weeks. Your total score (ranging from 5 to 25) helps healthcare professionals understand the degree of ED you're experiencing and recommend appropriate treatment options, from lifestyle changes to prescription medicines such as sildenafil or tadalafil.

What is the IIEF-5 questionnaire and how does it work?

The IIEF-5 questionnaire consists of five carefully designed questions that assess different aspects of erectile function. Each question is scored from 0 to 5 (or 1 to 5 depending on the question), with higher scores indicating better erectile function. The questions cover your confidence in achieving an erection, the firmness of your erections, your ability to maintain an erection during intercourse, the difficulty in maintaining an erection until completion, and how often intercourse has been satisfactory for you.

Healthcare professionals use the total score to classify ED severity: 22–25 indicates no ED, 17–21 suggests mild ED, 12–16 indicates mild to moderate ED, 8–11 suggests moderate ED, and 5–7 indicates severe ED [2]. This standardised scoring system allows clinicians to track changes over time and measure how well treatments are working. The questionnaire is quick to complete—usually taking just a few minutes—and provides valuable information that helps guide treatment decisions.

At Cured Pharmacy, our online consultation includes questions based on validated assessment tools to understand your symptoms and medical history. A UK-registered prescriber reviews every consultation to ensure any recommended treatment is safe and appropriate for you. The IIEF-5 score is one of several factors considered alongside your overall health, current medications, and any underlying conditions that might contribute to ED.

Why is the IIEF-5 questionnaire important for diagnosing ED?

The IIEF-5 questionnaire provides an objective, standardised way to assess erectile dysfunction, moving beyond vague descriptions to quantifiable data. This is particularly valuable because ED exists on a spectrum—many men experience occasional difficulties rather than complete inability to achieve erections. By assigning a numerical score, the questionnaire helps distinguish between mild occasional problems and more severe, persistent dysfunction that requires medical intervention [2].

Using a validated tool like the IIEF-5 also helps healthcare professionals identify patterns and monitor progress. If you start treatment with a PDE5 inhibitor such as sildenafil (Viagra) or tadalafil (Cialis), repeating the questionnaire after a few weeks can objectively show whether your erectile function has improved. This evidence-based approach ensures that treatment decisions are based on measurable outcomes rather than subjective impressions alone.

Additionally, the IIEF-5 can help identify when ED might be a symptom of an underlying health condition. Research shows that erectile dysfunction often appears before other symptoms of cardiovascular disease or diabetes [10]. A low IIEF-5 score, especially in younger men or those with risk factors, should prompt a comprehensive health review with a GP to check blood pressure, cholesterol, blood sugar, and cardiovascular health. Early detection of these conditions can be life-saving.

When should you see a doctor about your IIEF-5 score?

If your IIEF-5 questionnaire score indicates moderate to severe ED (a score of 16 or below), or if you're experiencing new or worsening erectile difficulties, it's important to speak with a healthcare professional. Even if your score suggests mild ED, a consultation is valuable if the problem is causing you distress or affecting your relationship. Your GP can perform blood tests to check for diabetes, low testosterone, high cholesterol, and other conditions that commonly contribute to ED [1][2].

You should seek medical advice promptly if ED develops suddenly, if you're under 40, or if you have other symptoms such as reduced libido, fatigue, or problems with urination. These may indicate hormonal imbalances, prostate issues, or other health concerns that need investigation. Remember that ED is often an early warning sign of cardiovascular disease, so addressing it can have broader health benefits beyond sexual function.

Common causes of erectile dysfunction identified through IIEF-5 assessment

Erectile dysfunction has many potential causes, and the IIEF-5 questionnaire helps identify the severity but not the underlying reason. Physical causes include cardiovascular disease, diabetes, high blood pressure, high cholesterol, obesity, hormonal imbalances (particularly low testosterone), neurological conditions, and side effects from certain medications [1]. Blood flow problems are particularly common—erections require healthy blood vessels, and conditions that damage or narrow arteries (such as atherosclerosis) can impair erectile function.

Psychological factors also play a significant role, either alone or in combination with physical causes. Stress, anxiety, depression, relationship difficulties, and performance anxiety can all contribute to ED. In younger men, psychological causes are more common, while in older men, physical factors tend to predominate. However, even when ED starts with a physical cause, the resulting anxiety and loss of confidence can create a psychological component that perpetuates the problem [2].

Lifestyle factors significantly influence erectile function. Smoking damages blood vessels and is strongly associated with ED. Heavy alcohol consumption, lack of physical activity, poor diet, and being overweight all increase the risk. Certain medications—including some antidepressants, blood pressure tablets, and antihistamines—can cause or worsen ED as a side effect. If your IIEF-5 score suggests ED, reviewing your medications with a healthcare professional is an important step, though you should never stop a prescribed medicine without medical advice.

Treatment options based on your IIEF-5 questionnaire results

Treatment for erectile dysfunction depends on the severity indicated by your IIEF-5 score, underlying causes, and your personal preferences. For mild ED, lifestyle modifications may be sufficient: stopping smoking, reducing alcohol intake, losing weight if overweight, exercising regularly, and managing stress can all improve erectile function [1][2]. These changes benefit overall health and may restore normal function without medication.

For moderate to severe ED, or when lifestyle changes alone are insufficient, prescription medicines called PDE5 inhibitors are the first-line treatment. These include sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Spedra). All work by enhancing the natural erectile response to sexual stimulation—they increase blood flow to the penis when you're aroused but don't cause automatic erections [3][4][5][6]. Clinical trials have shown these medicines can significantly improve erectile function across all severity levels, though individual response varies.

At Cured Pharmacy, we offer a range of PDE5 inhibitors at different price points. Sildenafil is available from £0.45 per tablet (£0.36 with first-order code Ednew), making effective treatment accessible. Tadalafil offers the advantage of lasting up to 36 hours, providing more spontaneity. All prescription treatments require an online consultation reviewed by a UK-registered prescriber who will assess your IIEF-5 responses, medical history, and current medications to ensure safety. If PDE5 inhibitors aren't suitable or effective, your GP can discuss alternatives such as vacuum devices, alprostadil (Vitaros cream or Caverject injection), or referral to a specialist [7].

How to choose the right ED treatment for your score

The choice of treatment depends on several factors beyond your IIEF-5 score. Consider how spontaneous you want to be: sildenafil and vardenafil work for 4–6 hours and are taken about an hour before sex, while tadalafil can last up to 36 hours or be taken daily at a lower dose for continuous effect [3][4][5]. Avanafil (Spedra) works fastest, often within 15–30 minutes [6][11]. Your lifestyle, frequency of sexual activity, and personal preference all matter.

Your medical history and current medications are crucial. PDE5 inhibitors must never be taken with nitrates (GTN spray, isosorbide tablets), nicorandil, or riociguat, as this combination can cause a dangerous drop in blood pressure. If you take alpha-blockers for prostate symptoms or blood pressure, you'll need the lowest starting dose and careful monitoring. Certain antifungals, antibiotics, and HIV medicines interact with PDE5 inhibitors and require dose adjustments [3][4][5][6]. Our prescribers check all these factors during your consultation to recommend the safest, most effective option for you.

Using the IIEF-5 questionnaire to monitor treatment progress

One of the most valuable uses of the IIEF-5 questionnaire is tracking how well your treatment is working. After starting a PDE5 inhibitor or making lifestyle changes, repeating the questionnaire after 4–8 weeks provides objective evidence of improvement. An increase in your total score indicates that erectile function is improving, while a stable or declining score suggests the current approach may need adjustment [2].

It's important to give treatments a fair trial. PDE5 inhibitors may not work optimally on the first attempt—factors such as timing, food intake, anxiety, and insufficient sexual stimulation can affect results. Most prescribers recommend trying a medicine on at least 4–8 separate occasions before concluding it's ineffective. If your IIEF-5 score hasn't improved after an adequate trial, options include trying a different PDE5 inhibitor (as individual response varies), adjusting the dose, addressing psychological factors, or investigating underlying health conditions more thoroughly.

Regular monitoring also helps identify when ED is worsening, which may signal progression of an underlying condition such as diabetes or cardiovascular disease. A declining IIEF-5 score despite treatment warrants a review with your GP to reassess your overall health. Conversely, significant improvement in your score can boost confidence and reduce performance anxiety, creating a positive cycle that further enhances sexual function. Keeping track of your scores over time provides valuable information for you and your healthcare team.

Practical steps after completing your IIEF-5 questionnaire assessment

After completing the IIEF-5 questionnaire and understanding your score, the next step is to seek appropriate help. If your score indicates moderate to severe ED (16 or below), or if ED is causing you distress regardless of the score, arrange a consultation with a healthcare professional. Your GP can perform a physical examination, check blood pressure, and order blood tests for diabetes, cholesterol, testosterone, and thyroid function. These investigations help identify treatable underlying causes [1][2].

While waiting for an appointment or alongside medical treatment, start making lifestyle improvements. If you smoke, seek support to quit—smoking cessation services are available free on the NHS. Aim for at least 150 minutes of moderate exercise weekly, reduce alcohol to within recommended limits (14 units per week), and work towards a healthy weight if overweight. These changes improve cardiovascular health, which directly benefits erectile function. Managing stress through relaxation techniques, adequate sleep, and open communication with your partner can also help, particularly if anxiety contributes to your ED.

For convenient access to prescription ED treatments, Cured Pharmacy offers a confidential online consultation service. Complete a medical questionnaire (which includes IIEF-5-style questions), and a UK-registered prescriber will review your responses, medical history, and current medications. If treatment is appropriate and safe, your medicine is dispensed by our GPhC-registered pharmacy and delivered discreetly to your door. We offer a range of options from affordable generic sildenafil at £0.45 per tablet to longer-acting tadalafil and faster-acting avanafil, ensuring you can find a treatment that fits your needs and budget. All prescription medicines require clinical assessment—we never supply ED treatments without proper medical review.

What to expect during an ED consultation

Whether consulting your GP or using an online service like Cured Pharmacy, expect questions about your erectile function (often using the IIEF-5 or similar tool), general health, cardiovascular risk factors, current medications, and lifestyle. Be honest and specific—healthcare professionals are experienced in discussing sexual health and need accurate information to help you safely. You'll be asked about morning erections (which can help distinguish physical from psychological causes) and whether you can achieve erections through masturbation.

The prescriber will check for contraindications to PDE5 inhibitors, particularly use of nitrates, recent heart attack or stroke, severe heart failure, very low blood pressure, or previous sudden vision loss. They'll review all your current medicines for interactions, especially alpha-blockers, certain antifungals, HIV medicines, and other drugs that affect how PDE5 inhibitors are metabolised [3][4][5][6]. Based on this assessment, they'll recommend the most suitable treatment, starting dose, and any precautions. Follow-up is important to assess effectiveness and adjust treatment if needed.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 17 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 17 October 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 17 October 2026]
4. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 17 October 2026]
5. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 17 October 2026]
6. Joint Formulary Committee. (n.d.). Avanafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/avanafil/ [accessed 17 October 2026]
7. Goldstein, I., Lue, T. F., Padma-Nathan, H., Rosen, R. C., Steers, W. D., & Wicker, P. A. (1998). Oral sildenafil in the treatment of erectile dysfunction. New England Journal of Medicine, 338(20), 1397–1404. https://pubmed.ncbi.nlm.nih.gov/9580646/ [accessed 17 October 2026]
8. 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 17 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.