Vardenafil — evidence-based review (for educational purposes only, not a substitute for medical advice)

Vardenafil is a prescription medicine used mainly to treat erectile dysfunction (ED). Below is a plain-language, evidence-based overview of what is known, what remains uncertain, and how to approach decisions safely. This article is for general information and does not replace consultation with a qualified healthcare professional.

Quick summary

• Vardenafil belongs to a group of medicines called PDE5 inhibitors, also used for erectile dysfunction.
• It improves blood flow to the penis during sexual stimulation, helping achieve and maintain an erection.
• Large clinical trials show it works better than placebo for many men with ED.
• Common side effects include headache, flushing, nasal congestion, and indigestion.
• It must not be used with nitrates (certain heart medications) due to risk of dangerous low blood pressure.

What is known

1. How vardenafil works

Vardenafil blocks an enzyme called phosphodiesterase type 5 (PDE5). This enzyme normally breaks down a substance (cGMP) that helps relax smooth muscle in blood vessels. By blocking PDE5, vardenafil increases cGMP levels, leading to better blood flow in the penis when a person is sexually stimulated.

Important: it does not cause an automatic erection. Sexual stimulation is still required.

2. Effectiveness for erectile dysfunction

Multiple randomized controlled trials have shown that vardenafil improves erectile function compared with placebo. Benefits have been observed in:

• Men with general erectile dysfunction
• Men with diabetes
• Men after certain prostate surgeries

Improvements are typically measured using standardized questionnaires such as the International Index of Erectile Function (IIEF). On average, more men taking vardenafil report successful intercourse attempts compared with those taking placebo.

3. Onset and duration

Vardenafil is usually taken before anticipated sexual activity. It generally starts working within about 30–60 minutes. Its effect may last several hours, though this varies between individuals.

Food, especially high-fat meals, may slightly delay absorption.

4. Safety profile and side effects

In clinical studies and post-marketing data, common side effects include:

• Headache
• Facial flushing
• Nasal congestion
• Indigestion (dyspepsia)
• Dizziness

Less common but more serious risks include:

• Sudden drop in blood pressure (especially with nitrates)
• Visual disturbances (rare)
• Hearing changes (very rare)
• Prolonged erection lasting more than 4 hours (priapism), which requires urgent care

5. Drug interactions and contraindications

Vardenafil should not be used with:

• Nitrates (e.g., nitroglycerin, isosorbide) — risk of severe hypotension
• Some strong CYP3A4 inhibitors (certain antifungals and antibiotics)

Caution is needed in people with significant heart disease, recent stroke or heart attack, severe liver disease, or certain heart rhythm disorders.

What is unclear / where evidence is limited

• Long-term comparative effectiveness: While vardenafil is effective, head-to-head comparisons with other PDE5 inhibitors (such as sildenafil or tadalafil) show broadly similar results. Superiority of one over another is not firmly established for most patients.
• Use in complex cardiovascular disease: Although generally safe when prescribed appropriately, data are more limited in people with unstable heart conditions.
• Psychological vs. physical ED: Evidence is strongest for physical (organic) causes. In primarily psychological ED, medication may help, but outcomes vary and psychological therapy may be equally or more important.
• Use outside approved indications: Research on off-label uses is limited and not well established.

Overview of approaches

Management of erectile dysfunction often includes several components:

• Lifestyle measures (weight control, exercise, smoking cessation)
• Management of chronic diseases (diabetes, hypertension)
• Psychological or relationship counseling
• Medications such as PDE5 inhibitors (including vardenafil)
• Other treatments (vacuum devices, injections, surgery in selected cases)

Vardenafil is one of several first-line medication options recommended in major urology guidelines.

Typical dosing schedules and adjustments are described in official prescribing information from regulatory authorities such as the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA). For example, see the FDA-approved label for Levitra (vardenafil):
FDA drug labeling database.

Do not start, stop, or adjust medication without consulting a healthcare professional.

Evidence summary table

Statement	Confidence level	Why
Vardenafil improves erectile function compared with placebo	High	Supported by multiple randomized controlled trials and guideline recommendations
It works only with sexual stimulation	High	Mechanism of action is well established and consistent across studies
It is generally safe when prescribed appropriately	High	Extensive post-marketing data and regulatory review
One PDE5 inhibitor is clearly superior to others	Low–Medium	Comparative studies show similar overall effectiveness; differences are often individual
It is safe in all patients with heart disease	Low	Contraindicated or requires caution in certain cardiovascular conditions

Practical recommendations

General safety measures

• Discuss all current medications with your doctor, especially heart medications.
• Seek urgent medical care for chest pain after taking the drug.
• Get emergency help if an erection lasts more than 4 hours.

When to see a doctor

• Erectile dysfunction persists for more than a few weeks.
• You have diabetes, high blood pressure, or heart disease.
• You experience sudden vision or hearing changes.

How to prepare for a consultation

• List all medications and supplements you take.
• Note when symptoms started and how often they occur.
• Be ready to discuss lifestyle factors (stress, sleep, alcohol).

You may also find it helpful to read about erectile dysfunction causes and diagnosis, explore lifestyle approaches for vascular health, and understand how PDE5 inhibitors differ. For broader context, see our overview of men’s health screening recommendations.

Sources

• American Urological Association (AUA). Erectile Dysfunction Guideline.
• European Association of Urology (EAU). Guidelines on Sexual and Reproductive Health.
• U.S. Food and Drug Administration (FDA). Vardenafil (Levitra) prescribing information.
• European Medicines Agency (EMA). Assessment reports for vardenafil-containing products.
• National Institutes of Health (NIH) – MedlinePlus: Vardenafil.