Vardenafil is a prescription pill for erectile dysfunction (ED). MedlinePlus says it works by increasing blood flow to the penis during sexual stimulation. It is a different drug from Cialis (tadalafil), but it belongs to the same drug class as Viagra (sildenafil) and Cialis, and it shares several of their warnings.
What is vardenafil, and how does it work?
Vardenafil is sold under the brand names Levitra, Staxyn and Vivanza, according to the Wikipedia entry on vardenafil. It is a PDE5 inhibitor. The Levitra FDA label describes it as a selective inhibitor of the PDE5 enzyme, and says that because sexual stimulation is needed to release nitric oxide locally, PDE5 inhibition has no effect without that stimulation.
Vardenafil comes as a regular tablet and as a rapidly disintegrating tablet that dissolves on the tongue. MedlinePlus notes that the two forms cannot be substituted for each other, so the form on your prescription matters.
In the US, vardenafil is prescription-only. The DailyMed vardenafil label is the official US product label. As of October 29, 2026, the Wikipedia entry lists the US status as prescription only. This is information, not legal advice.
Is vardenafil better than Viagra or Cialis?
The three drugs are close relatives, and none is a simple winner. The Wikipedia entry says vardenafil’s indications and contraindications match those of other PDE5 inhibitors. The table below shows how the drugs differ.
| Drug | Brand name listed | What the sources say about it |
|---|---|---|
| Vardenafil | Levitra, Staxyn, Vivanza | Its effective time is described as “comparable to but somewhat longer than” sildenafil’s (Wikipedia). |
| Sildenafil | Viagra | Closely related in function to vardenafil. The molecules differ in the position of one nitrogen atom and in one small ethyl group (Wikipedia). |
| Tadalafil | Cialis | Structurally different from both sildenafil and vardenafil (Wikipedia). |
MedlinePlus lists sildenafil (Viagra) and tadalafil (Cialis) alongside vardenafil in its warning about sudden vision loss. Which drug suits you depends on your health, your other medicines and how each has worked for you. Your prescriber can compare them with you.
The guide cannot rank these drugs for you, and no source here gives a strength comparison between vardenafil and sildenafil. Ask your prescriber how the options compare for your situation.
How long does vardenafil take to kick in, and how long does it last?
The Levitra FDA label reports that after a single 20 mg dose in healthy volunteers taken on an empty stomach, the highest blood levels were usually reached between 30 minutes and 2 hours, with a median of 60 minutes. The same label says high-fat meals reduced the peak level by 18% to 50%.
The label gives the drug’s terminal half-life as about 4 to 5 hours. Half-life describes how long the drug stays in your blood. It is not a measure of how long an erection lasts.
How long does 20 mg of vardenafil last?
The older Levitra label’s blood-level figures and the 4 to 5 hour half-life are the best timing data in these sources. That label, dated 2008, describes 20 mg as the “Maximum Recommended Human Dose” (MRHD). The FDA page that hosts it says, “This label may not be the latest approved by FDA.” For current maximum doses and strengths, check the current label on DailyMed or Drugs@FDA, or ask a pharmacist. Your prescriber will tell you how long your own dose is expected to work.
Is 10 mg enough, and can I take 40 mg?
The older Levitra label lists tablet strengths of 2.5 mg, 5 mg, 10 mg and 20 mg. Check the current label for the strengths sold today. MedlinePlus says doctors usually start with an average dose and adjust it based on how the medicine works for you. Whether 10 mg is right for you is a decision for your prescriber.
The 40 mg figure in the older Levitra label appears only as a study dose, described as “twice the maximum daily recommended dose.” MedlinePlus is direct on this point: “Do not take more or less of it or take it more often than prescribed by your doctor.” If you are unsure which strength applies, ask your prescriber or pharmacist before you change anything.
Vardenafil side effects
MedlinePlus lists the common side effects below. Cleveland Clinic lists a similar set and adds dizziness and muscle pain.
| Type | Side effects named in the sources | What to do |
|---|---|---|
| Common | Headache, upset stomach, heartburn, flushing, stuffy or runny nose, flu-like symptoms (MedlinePlus); dizziness, muscle pain (Cleveland Clinic) | Tell your doctor if these are severe or do not go away. |
| Serious: call your doctor right away | An erection that lasts longer than 4 hours; sudden severe loss of vision; blurred vision; changes in color vision; dizziness; sudden decrease or loss of hearing; ringing in the ears; swelling of the face, throat, tongue, lips or limbs; hoarseness; trouble breathing or swallowing; fainting; hives; rash (MedlinePlus) | Call your doctor immediately. |
| Chest pain during sex | MedlinePlus says sexual activity may strain the heart, especially with heart disease. | Call your doctor immediately and avoid sexual activity until your doctor says otherwise. |
| Priapism | The Levitra label says rare reports of erections longer than 4 hours and painful erections longer than 6 hours have occurred with this class, including vardenafil. If priapism is not treated immediately, the label says penile tissue damage and permanent loss of potency may result. | Seek immediate medical help if an erection lasts longer than 4 hours. |
Vision and hearing deserve a closer look. MedlinePlus says some people lost some or all of their vision after taking vardenafil or similar drugs, and in some cases the loss was permanent. It also says some people had a sudden decrease or loss of hearing, usually in one ear, which may not get better. MedlinePlus says the link to the medicine is uncertain in both cases.
Blood pressure can also change. In the label’s clinical pharmacology study, a single 20 mg dose lowered supine blood pressure by a mean of 7 mmHg systolic and 8 mmHg diastolic compared with placebo.
Who should not take vardenafil, or should be careful?
| Situation | What the sources say |
|---|---|
| Riociguat or nitrates | MedlinePlus: do not take vardenafil if you are taking or have recently taken riociguat (Adempas) or nitrates, including nitroglycerin. Also avoid street drugs containing nitrates, such as amyl nitrate and butyl nitrate (“poppers”). |
| Strong or moderate CYP3A4 inhibitors | The older Levitra label names ritonavir, indinavir, ketoconazole, itraconazole and erythromycin. With ritonavir, the label reports a 49-fold increase in vardenafil exposure at a 5 mg dose. |
| Grapefruit | MedlinePlus says to talk to your doctor about eating grapefruit or drinking grapefruit juice. The label says grapefruit juice would likely increase vardenafil exposure. |
| Blood pressure medicines | The label says vardenafil may add to the blood-pressure-lowering effects of antihypertensive drugs. It names alpha-blockers such as terazosin and tamsulosin. |
| Heart rhythm drugs and QT problems | The label says people with congenital QT prolongation, and those taking Class IA or Class III antiarrhythmics such as amiodarone or sotalol, should avoid vardenafil. |
| St. John’s wort | MedlinePlus names this herbal product as one that may interact with vardenafil. |
| Women | MedlinePlus says vardenafil is only for use in males. Women should not take it, especially if pregnant, could become pregnant, or are breast-feeding. |
| Other conditions to tell your doctor about | MedlinePlus lists heart disease, irregular heartbeat, a heart attack or stroke (now or in the past), high or low blood pressure, liver or kidney disease, a bleeding disorder, sickle cell anemia, multiple myeloma, leukemia, Peyronie’s disease, and retinitis pigmentosus or past severe vision loss. |
| Rapidly disintegrating tablets | MedlinePlus says these contain aspartame, a source of phenylalanine, which matters if you have phenylketonuria. They are also sweetened with sorbitol, which matters if you have fructose intolerance. |
Does vardenafil work, and what do the studies show?
The Levitra label describes four major double-blind, randomized, placebo-controlled trials in 2,431 men aged 20 to 83, using 5 mg, 10 mg and 20 mg doses. The label says the trials were fixed-dose, parallel-design, multicenter studies.
The label also reports an eye study. In a double-blind, placebo-controlled trial of 52 men given at least 15 doses of 20 mg over 8 weeks, vardenafil did not produce clinically significant changes in retinal function compared with placebo. Two men reported transient cyanopsia, meaning objects looked blue.
MedlinePlus is clear about what the drug does not do. It is not a cure for erectile dysfunction, does not increase sexual desire, does not prevent pregnancy, and does not prevent sexually transmitted diseases such as HIV.
Is vardenafil legit, and where should you get it?
Yes. Vardenafil is an FDA-approved prescription drug, sold under the Levitra brand, which the DailyMed reference in the Wikipedia entry dates to an initial US approval in 2003. For current labeling, the FDA points to its Drugs@FDA database.
The risk is in products that copy the idea of a pill without the prescription. The FDA’s tainted sexual enhancement products warning says many products that claim to help with sexual enhancement or treat sexual dysfunction are likely to be contaminated with dangerous hidden ingredients. It says these are sometimes falsely advertised as dietary supplements, and that they are sold online and in stores. Wikipedia notes that the FDA has found vardenafil and other synthetic PDE5 inhibitors in products marketed as “herbal” or “all natural” male enhancement.
Prescription drugs are dispensed through a pharmacy with a valid prescription. Check that the drug you receive matches the strength and form your prescriber chose.
How much does vardenafil cost?
Prices vary by pharmacy, insurance plan, strength and form. Check today’s price directly with your pharmacy or insurer before you plan around a cost.
Can you just treat ED yourself without a prescription?
Vardenafil is a prescription drug, so it cannot be substituted with a home remedy or a supplement. For the limits of breathing methods, see our guide to breathing practice claims. The National Institute of Diabetes and Digestive and Kidney Diseases says ED is common and “can often be treated,” and that your health care professional can help find the cause and talk with you about treatments. Its ED treatment page lists habits that may help prevent or improve ED:
- Quit smoking.
- Eat a healthy diet, and consider working with a registered dietitian.
- Keep a healthy weight, which can improve testosterone levels and self-esteem.
- Be physically active. The Physical Activity Guidelines for Americans recommend at least 150 minutes of moderate activity each week.
- Manage stress, for example with breathing exercises.
- Avoid recreational and illicit drugs and limit alcohol.
The NIDDK definition page lists diabetes, heart disease, obesity, some blood pressure medicines and antidepressants, anxiety and stress as factors that make ED more likely.
Before you order or fill a prescription
- List every medicine you take, including nitrates, riociguat, alpha-blockers, HIV drugs, antifungals and St. John’s wort.
- Ask which strength and form fit your situation.
- Ask what to do if an erection lasts longer than 4 hours.
- Ask about any heart, blood pressure, liver, kidney, eye or hearing history.
- Ask how grapefruit fits into your routine.
- Check today’s price with your pharmacy or insurer.
- Store the tablets between 15 and 30 degrees C (59 and 86 degrees F), out of reach of children and pets, as Cleveland Clinic advises.
Sources in this guide: MedlinePlus vardenafil drug information, the Levitra FDA label, Cleveland Clinic vardenafil information, Wikipedia’s vardenafil entry.
By the Integrative Health Evidence Guide Team