Levitra (Vardenafil) Effects and Side Effects | Duration, Firmness, and Dosage Guide

Vardenafil, the active pharmaceutical ingredient in Levitra®, belongs to the PDE5 (phosphodiesterase type 5) inhibitor class. Compared with the other PDE5 inhibitors—sildenafil (Viagra®) and tadalafil (Cialis®)—vardenafil exhibits the highest selectivity for PDE5.

Vardenafil’s binding affinity for PDE5 is approximately 10 times greater than that of sildenafil, enabling sufficient efficacy even at lower doses. This high selectivity is what produces the clinical characteristics of rapid onset and firm erections. However, like sildenafil (Viagra®), concurrent use with nitrates (e.g., nitroglycerin) is contraindicated. If you are currently taking any medications, please inform your physician.

Vardenafil (Levitra®) was developed by Bayer Pharmaceuticals following the success of sildenafil (Viagra®), with the goal of creating a PDE5 inhibitor with greater speed of onset and selectivity. The development concept was to address Viagra®’s limitations, namely its susceptibility to food interactions and slower onset of action.

• 2003: Approved as an ED medication by European authorities and the FDA (U.S. Food and Drug Administration)
• April 2004: Japan’s Ministry of Health, Labour and Welfare approved the 5 mg and 10 mg formulations
• 2007: The 20 mg tablet received additional approval in Japan, enabling treatment for moderate-to-severe ED
• 2020: Bayer Pharmaceuticals announced the discontinuation of branded Levitra® in Japan
• 2021 onward: Domestic generic vardenafil tablets became available from multiple manufacturers

Although the branded product has been discontinued, generic vardenafil tablets contain the same active ingredient and deliver equivalent efficacy. Men’s Care Clinic continues to prescribe them.

Vardenafil (Levitra®) is available in three dosages—5 mg, 10 mg, and 20 mg—and the physician prescribes the appropriate dose based on the severity of ED and the patient’s overall health.

• 5 mg: Suitable as an initial dose for mild ED, elderly patients, or those concerned about side effects. Provides a milder effect with the lowest risk of adverse reactions
• 10 mg: The most commonly prescribed dose in Japan. Most patients experience satisfactory results at this dosage
• 20 mg: Indicated for moderate-to-severe ED. Offers the fastest onset (approximately 15 minutes) and longest duration (approximately 7–10 hours). It is the most frequently prescribed dose internationally

First-time users typically start with 10 mg, and the dose is adjusted based on efficacy and tolerability. Do not change the dose on your own; always follow your physician’s instructions.

Vardenafil (Levitra®) shares the same PDE5 inhibition mechanism as sildenafil (Viagra®) and tadalafil (Cialis®), but is distinguished by a stronger binding affinity to the PDE5 enzyme.

• Step 1 (Sexual stimulation): When the brain receives sexual stimulation, nitric oxide (NO) is released to the penis through the nervous system
• Step 2 (cGMP increase): NO triggers the production of cGMP (cyclic guanosine monophosphate), which relaxes the smooth muscle of the corpus cavernosum and dilates blood vessels
• Step 3 (Erection): A large volume of blood flows into the corpus cavernosum, and the resulting pressure produces a firm erection
• Step 4 (PDE5 activity): Normally, the PDE5 enzyme breaks down cGMP to end the erection. In ED, this breakdown occurs excessively, preventing an adequate erection from being maintained

Vardenafil (Levitra®) potently inhibits PDE5, preventing the breakdown of cGMP and efficiently increasing blood flow to the penis. Because its selectivity for PDE5 is approximately 10 times higher than sildenafil, it can produce strong effects even at lower doses. Individual responses may vary, so please consult your physician.

Among all ED medications, vardenafil (Levitra®) receives particularly high marks for erectile firmness. In clinical trials using the EHS (Erection Hardness Score), the vardenafil 20 mg group achieved a score of 4 (fully hard) at a significantly higher rate compared to the placebo group.

The reason vardenafil is preferred by men experiencing loss of erection during intercourse lies in its ability to sustain firmness. Due to its strong binding affinity for PDE5, cGMP levels remain stable, making it less likely for firmness to decrease during intercourse. It is not uncommon in clinical practice for patients who felt that sildenafil (Viagra®) was effective but experienced a decline in firmness during the act to see improvement after switching to vardenafil.

However, perceived firmness varies between individuals. To find the ED medication that works best for you, we recommend consulting with a physician at Men’s Care Clinic.

Patients who have been prescribed vardenafil (generic Levitra®) at our clinic have shared the following feedback:

• Male, 40s: “It works faster than Viagra, and I don’t have to worry as much about meals. The firmness is definitely noticeable.”
• Male, 50s: “I used to struggle with losing my erection during intercourse, but since switching to vardenafil, I can maintain it throughout.”
• Male, 30s: “I was prescribed 20 mg, and it started working in about 15 minutes. The speed of onset really is remarkable.”

*These are individual experiences and do not guarantee results. Effects vary from person to person. If you have questions, please feel free to schedule a free consultation.

When taken on an empty stomach, vardenafil can begin working in as little as 15 minutes. Most patients notice effects within 20–30 minutes, and taking it 30 minutes before sexual activity is considered optimal.

This rapid onset is attributable to vardenafil’s pharmacokinetics. After oral administration, vardenafil is absorbed quickly, and the time to reach peak plasma concentration (T_max) is reported to be approximately 0.7–0.9 hours on an empty stomach. This is notably shorter than sildenafil’s T_max (approximately 1 hour), which accounts for the clinical difference in speed of onset.

However, if taken after a high-fat meal, absorption is delayed and onset may take more than one hour. For maximum speed of onset, taking vardenafil on an empty stomach is recommended.

The duration of vardenafil’s effects varies by dosage. General guidelines are as follows:

• 5 mg: Approximately 4–5 hours. Suitable for mild ED or first-time use
• 10 mg: Approximately 5–7 hours. The standard prescribed dose in Japan, providing sufficient duration for most patients
• 20 mg: Approximately 7–10 hours. The longest duration, and the most frequently prescribed dose internationally

Peak effect (the window of strongest efficacy) occurs 45 minutes to 2 hours after administration. Sexual activity during this window is most likely to yield optimal results. Even within the overall duration, effects gradually diminish after the peak. Please discuss appropriate dosage with your physician.

Examining the plasma concentration curve of vardenafil over time makes the differences from other ED medications clearer.

• 0–15 minutes: Absorption begins and plasma concentration rises rapidly. Some patients may begin to notice effects at this stage
• 15–45 minutes: Plasma concentration rises sharply toward C_max. Most patients clearly perceive the effects during this period
• 45 minutes–2 hours: Peak plasma concentration. This is the window of strongest effect and the optimal time for sexual activity
• 2–5 hours: Plasma concentration gradually declines, but sufficient efficacy is maintained
• 5–8 hours: Effects progressively diminish. Based on vardenafil’s elimination half-life (approximately 4–5 hours), the drug is being cleared from the body
• After 8 hours: Effects have essentially resolved. There is virtually no carryover to the next day

Compared with sildenafil (Viagra®), vardenafil’s concentration curve rises more steeply and peaks earlier. In contrast, tadalafil (Cialis®) rises gradually and sustains over a longer period. Understanding these differences helps inform the right choice. If you have questions about optimal timing, please consult your physician.

Compared with the 10 mg dose, vardenafil 20 mg offers approximately 5 minutes faster onset and 2–3 hours longer duration. In a large-scale international clinical trial (Porst H et al., 2006), the erectile improvement rate in the 20 mg group exceeded 85%, significantly surpassing the 10 mg group (approximately 75%).

The 20 mg dose tends to be selected in the following situations:

• Insufficient response to 10 mg: Patients with a larger body frame or moderate-to-severe ED
• Need for extended duration: When longer-lasting coverage is desired, such as during a date
• Psychological reassurance: The tangible sense of strong efficacy can provide emotional confidence

The primary differences between 10 mg and 20 mg are the intensity and duration of effects. While 10 mg is the standard dose in Japan and works well for most patients, 20 mg produces a stronger vasodilatory effect, often delivering noticeably greater firmness and sustained erection quality.

On the other hand, the incidence of side effects (headache, flushing, palpitations, etc.) is somewhat higher with 20 mg. Clinical trial data indicate that the side-effect rate is approximately 10–15% with 10 mg versus approximately 15–20% with 20 mg. It is important to discuss the balance of efficacy and tolerability with your physician to determine the optimal dose.

If you do not notice an effect after taking vardenafil, first review the following points:

• Did you take it after a meal? Absorption decreases significantly after a high-fat meal. Try taking it on an empty stomach
• Was there adequate sexual stimulation? Vardenafil does not work without sexual arousal. Sufficient foreplay is important
• Have you tried it enough times? Some patients do not experience the full effect on the first attempt. Nervousness and performance anxiety can be contributing factors—trying 2–3 times may help
• Is the dose sufficient? If 10 mg was ineffective, increasing to 20 mg may improve results

If none of these adjustments help, switching to sildenafil (Viagra®) or tadalafil (Cialis®) may be beneficial. Our clinic prescribes all three ED medications, so please feel free to consult with us.

Vardenafil (Levitra®) is most effective when taken on an empty stomach. Under fasting conditions, effects can appear in as little as 15 minutes, and peak plasma concentration is reached optimally.

While vardenafil is considered less susceptible to food interactions than sildenafil (Viagra®), it is not completely unaffected. In particular, taking it after a high-fat meal (700 kcal or more, 30% or more fat) has been reported to reduce C_max by approximately 18–50%.

• Optimal: Take with water on an empty stomach, 30 minutes before sexual activity
• Acceptable: After a light meal (salad, rice ball, or other low-fat foods), the impact is minimal
• Avoid: Immediately after high-fat meals such as steak, fried food, or ramen

If you are unsure about meal timing, a good rule of thumb is to take vardenafil at least 2 hours after eating.

A moderate amount of alcohol (1–2 beers or 1–2 glasses of wine) is generally not a problem. In fact, a moderate amount of alcohol can have a relaxing effect that eases psychological tension, and in some cases may even enhance the perceived benefit of the medication.

However, heavy drinking should be avoided for the following reasons:

• Compounded vasodilation: Both vardenafil and alcohol are vasodilators. Excessive alcohol consumption can lead to an excessive drop in blood pressure, increasing the risk of dizziness and lightheadedness
• Reduced erectile response: Alcohol’s central nervous system depressant effect can dull the transmission of sexual arousal, potentially counteracting vardenafil’s effects
• Impaired judgment: Heavy drinking may also interfere with safe sexual practices

If you plan to drink on a day you wish to use vardenafil, either control your alcohol intake or consider using the medication on a different occasion. Please consult your physician if you have concerns.

There are currently three ED medications approved in Japan: sildenafil (Viagra®), vardenafil (Levitra®), and tadalafil (Cialis®). Each has distinct characteristics, and selecting the right one depends on your symptoms and lifestyle.

Choose vardenafil (Levitra®) for rapid onset and firmness, sildenafil (Viagra®) for proven safety and track record, or tadalafil (Cialis®) for extended duration. Our clinic stocks all three, so if you are unsure which is right for you, please feel free to ask.

The main side effects of vardenafil are related to the vasodilatory action of PDE5 inhibition. Based on domestic Phase III clinical trial data, the incidence rates are as follows:

• Flushing (approx. 10–15%): The most common side effect. Vasodilation causes a sensation of warmth in the face or body. Typically resolves within 2–3 hours. Management: Apply a cool cloth or stay in a cool environment
• Headache (approx. 8–12%): Caused by cerebral vasodilation. Usually a mild-to-moderate dull headache. Management: Over-the-counter analgesics (acetaminophen) are effective. NSAIDs such as loxoprofen may also be used
• Nasal congestion (approx. 5–8%): Due to vasodilation in the nasal mucosa. Resolves as the medication wears off. Management: Nasal sprays can provide temporary relief
• Palpitations (approx. 3–5%): Reflex tachycardia associated with vasodilation. Usually subsides within 30 minutes to 1 hour at rest
• Dyspepsia (approx. 2–4%): May include stomach discomfort or mild nausea. More common when taken on an empty stomach. A light snack beforehand can help prevent this
• Dizziness (approx. 1–3%): Mild dizziness from blood pressure reduction. Avoid standing up suddenly to help prevent this
• Visual disturbances (approx. 1–2%): Temporary blue-tinted vision or increased light sensitivity. Resolves within a few hours

These side effects typically resolve once the medication’s 5–8 hour effective window has passed. If symptoms persist into the next day, the dose may be too high. Please consult your physician about reducing it.

A common question is how vardenafil’s side effects compare with those of other ED medications.

In summary, the types and frequency of vardenafil’s side effects are nearly identical to those of sildenafil (Viagra®). However, there are some nuanced differences:

• Sildenafil (Viagra®) vs. Vardenafil (Levitra®): Side effects are similar in type and frequency. However, sildenafil tends to have a slightly higher incidence of visual abnormalities (blue-tinted vision), while vardenafil tends toward a slightly higher incidence of flushing
• Tadalafil (Cialis®) vs. Vardenafil (Levitra®): Tadalafil may have a somewhat lower overall incidence of side effects, but because it acts for a much longer period, any side effects that do occur may also persist longer. Vardenafil’s advantage is that side effects resolve within 5–8 hours

There is no evidence that vardenafil’s side effects are “particularly strong.” In fact, the fact that side effects are temporary and resolve along with the medication’s effects is a benefit. The duration of side effects can generally be thought of as matching the duration of the drug’s efficacy.

If you are concerned about side effects, we recommend starting with a lower dose (5 mg or 10 mg) to gauge your body’s response. Our clinic offers a free initial consultation where we thoroughly explain potential side-effect risks. Please feel free to reach out.

While the vast majority of vardenafil’s side effects are mild, the following serious adverse events have been reported in extremely rare cases:

• Priapism: An erection lasting more than 4 hours unrelated to sexual stimulation. If left untreated, irreversible damage to penile tissue may occur. If an erection persists for more than 4 hours, seek emergency medical attention immediately
• Sudden vision loss: Cases of non-arteritic anterior ischemic optic neuropathy (NAION) have been reported. Discontinue use immediately if sudden vision loss in one eye occurs and consult an ophthalmologist
• Sudden hearing loss: Cases of sudden sensorineural hearing loss have been reported. Discontinue use immediately if tinnitus or hearing loss occurs and consult an ENT specialist
• Severe allergic reactions: Urticaria, difficulty breathing, facial edema, etc. Extremely rare but requires emergency treatment if it occurs

Additionally, vardenafil is contraindicated in the following individuals:

• Patients taking nitrates: Including nitroglycerin and isosorbide nitrate. Risk of life-threatening hypotension
• Patients taking sGC stimulators (riociguat): Increased risk of hypotension
• Patients with severe hepatic impairment: Delayed drug metabolism significantly increases the risk of side effects
• Patients with untreated arrhythmias
• Patients with unstable angina
• Patients with hypotension (systolic BP <90 mmHg) or uncontrolled hypertension (systolic ≥170 mmHg, diastolic ≥100 mmHg)
• Patients who have had a stroke, cerebral hemorrhage, or myocardial infarction within the past 6 months
• Patients with retinitis pigmentosa
• Patients with a history of hypersensitivity to vardenafil
• Patients taking CYP3A4 inhibitors (e.g., ritonavir, itraconazole)
• Patients taking Class IA or Class III antiarrhythmic agents

If you have any existing medical conditions or are taking any medications, please inform your physician. At our clinic, we carefully review concomitant medications and medical history during the initial interview to ensure safe prescribing.

Generic medications are manufactured with the same active ingredient and dosage strength after the branded product’s patent has expired. Japan’s Ministry of Health, Labour and Welfare requires bioequivalence studies as part of the approval process, confirming that the generic achieves plasma concentration profiles equivalent to the branded product.

In other words, generic vardenafil tablets are equivalent to branded Levitra® in the following respects:

• Active ingredient: Vardenafil (same substance, same dosage strength)
• Efficacy: Equivalent PDE5 inhibition. No difference in onset speed, firmness, or duration
• Safety: Same types and frequency of side effects. Same contraindications and drug interactions
• Quality: Manufactured in facilities compliant with domestic GMP standards. Quality control is on par with the branded product

The only differences are tablet color, shape, excipients (such as coloring agents and coatings), and price. The notion that “generics don’t work” is a misconception—they can be used with confidence.

Men’s Care Clinic prescribes generic vardenafil tablets on a per-tablet, pay-as-you-go basis. There are no package deals or mandatory purchase quantities.

• Initial consultation fee: Free
• Prescriptions: Available in single-tablet quantities. No bulk purchase required
• Payment: Pay-as-you-go. Credit cards accepted
• Consultation options: In-person (Shimbashi, Akihabara, Omotesando) or online video consultation

ED treatment is not covered by Japan’s national health insurance, but our clinic ensures that patients can receive only as much medication as they need, without pressure. Please feel free to ask about pricing details during your consultation.

Please note that many ED medications sold through personal import services and online retailers are counterfeit. According to the World Health Organization (WHO), approximately 50% of ED medications purchased online are counterfeit. For your safety, always obtain a legitimate prescription from a medical facility.

Men’s Care Clinic’s ED treatment offers the following advantages:

• Single-tablet prescriptions: No bulk purchases required. Patients who want to “just try one tablet first” are welcome
• Pay-as-you-go: No subscription plans or minimum purchase requirements. Visit and receive a prescription only when you need it
• Free initial consultation: You only pay for the medication itself. Consultations with no commitment are also welcome
• By appointment only, private rooms: You will not encounter other patients. Maximum privacy is ensured
• All three ED medications available: Sildenafil (Viagra®), vardenafil (Levitra®), and tadalafil (Cialis®). We recommend the most suitable option based on your symptoms
• Partnership with Toyosu Hospital (Showa University affiliate): Referral pathway available for specialized examinations and treatment when needed

We welcome patients of all ages, from young men in their 20s experiencing ED to middle-aged and older men. If you think you might have ED but feel hesitant about visiting a clinic, please feel free to reach out for a consultation.

Men’s Care Clinic also offers online video consultations for ED medication prescriptions. With just a smartphone or computer, you can consult from the comfort of your home or anywhere else.

• No clinic visit needed: A physician conducts the consultation via video call
• Available nationwide: Ideal for those who cannot visit our Shimbashi, Akihabara, or Omotesando locations in person
• Home delivery: Medications are shipped in discreet packaging
• First-time patients welcome: We provide clear guidance for those new to online consultations

For those who are too busy to visit a clinic or prefer maximum privacy, online consultations make it easy to start ED treatment. Appointments can be booked online 24/7.

In domestic and international clinical trials, approximately 80% or more of patients taking vardenafil 20 mg reported improved erectile function. It is particularly highly rated for its rapid onset and firmness, and among the three ED medications, it has the highest selectivity for PDE5. However, results vary between individuals, and sexual stimulation is required for the medication to work. Please consult your physician for details.

Duration varies by dose: approximately 5–7 hours for 10 mg and approximately 7–10 hours for 20 mg. Peak effect occurs 45 minutes to 2 hours after taking the medication, after which efficacy gradually diminishes. It lasts longer than sildenafil (Viagra®; 4–6 hours) but shorter than tadalafil (Cialis®; 24–36 hours), offering a well-balanced duration.

When taken on an empty stomach, effects can begin in as little as 15 minutes, with most patients noticing results within 20–30 minutes. Taking it 30 minutes before sexual activity is optimal. Among the three ED medications, vardenafil has the fastest onset of action. Because high-fat meals can delay absorption, taking it on an empty stomach is recommended.

The main side effects are flushing (approx. 10–15%), headache (approx. 8–12%), nasal congestion (approx. 5–8%), and palpitations (approx. 3–5%). All are temporary symptoms associated with vasodilation and typically resolve naturally within 5–8 hours as the medication wears off. Serious side effects are extremely rare. If you notice anything unusual, please consult your physician promptly.

There is no evidence that vardenafil’s side effects are particularly strong. The types and frequency of side effects are nearly identical to those of sildenafil (Viagra®). In fact, because vardenafil’s duration is shorter than tadalafil (Cialis®), any side effects that do occur tend to resolve relatively quickly. If side effects are a concern, starting with a lower dose (5 mg or 10 mg) and monitoring your response is recommended.

The duration of vardenafil 20 mg is approximately 7–10 hours. Peak effect occurs 45 minutes to 2 hours after taking the medication, with sufficient efficacy sustained for approximately 5 additional hours. Based on its elimination half-life of approximately 4–5 hours, the effects are essentially resolved after 10 hours, with virtually no carryover to the following day.

Yes—the active ingredient, efficacy, and safety are the same as the branded product. Generic vardenafil tablets have been approved by Japan’s Ministry of Health, Labour and Welfare after confirming bioequivalence with the branded product. The only differences are tablet color, shape, excipients, and price. Although branded Levitra® has been discontinued, you can achieve the same results with the generic.

While vardenafil is considered less affected by food than sildenafil (Viagra®), C_max has been reported to decrease by 18–50% after a high-fat meal. Light meals (such as a salad or rice ball) have minimal impact. For maximum efficacy, taking it on an empty stomach is best. If you have eaten, wait at least 2 hours before taking the medication.

The main differences are speed of onset and firmness. Vardenafil takes effect within 15–30 minutes—roughly twice as fast as sildenafil (Viagra®; 30–60 minutes). Firmness ratings also tend to be somewhat higher for vardenafil. On the other hand, sildenafil (Viagra®) has over 25 years of prescribing history and the most extensive safety data. Vardenafil is considered less susceptible to food interactions.

The optimal choice depends on your goals and lifestyle. For rapid onset and firmness, choose vardenafil (Levitra®) (onset in 15–30 minutes, duration 5–8 hours). For extended duration, choose tadalafil (Cialis®) (onset in 30–60 minutes, duration 24–36 hours). If the timing of sexual activity is unpredictable, tadalafil may suit you better; if you want a medication timed for a specific evening, vardenafil is likely the better fit. Our clinic prescribes both—please consult with our physicians.

In clinical trials using the EHS (Erection Hardness Score), the proportion of patients achieving a score of 4 (fully hard) was significantly higher in the vardenafil 20 mg group compared to placebo. Among the three ED medications, vardenafil has the highest selectivity for PDE5 and the strongest ability to maintain cGMP levels, which translates into high clinical marks for firmness. However, individual experience varies, so please consult your physician if you have questions.

Vardenafil should be taken no more than once per 24-hour period, limited to one tablet per day. Daily continuous use is not recommended; the standard approach is to take it as needed before sexual activity. If daily dosing is preferred, low-dose daily tadalafil (Cialis® 2.5 mg or 5 mg) may be an alternative. Please discuss this with your physician.

Vardenafil is a prescription medication that requires a physician’s order. It can be prescribed at urology clinics or ED specialty clinics. Men’s Care Clinic offers prescriptions at our three locations (Shimbashi, Akihabara, and Omotesando) as well as through online video consultations. Purchasing through personal import services carries a high risk of receiving counterfeit products—always obtain your medication from a licensed medical facility.

Vardenafil is approved exclusively as an ED treatment for men and is not prescribed for women. While there has been some research into the use of PDE5 inhibitors for female sexual dysfunction, the evidence remains insufficient and safety has not been established. Women should not take this medication.