Vardenafil: A UK Guide to the PDE5 Inhibitor

Vardenafil is a PDE5 inhibitor for erectile dysfunction, the active ingredient in Levitra. It is taken as needed, about 25-60 minutes before sex, usually starting at 10 mg and adjusted between 5 mg and 20 mg by response and tolerability. It works only with sexual stimulation and must never be combined with nitrates. Common side effects include headache, flushing and a blocked nose. A prescriber assesses suitability, including heart health and other medicines.

Vardenafil is one of the four PDE5 inhibitors licensed for erectile dysfunction in the UK, known by the brand name Levitra. It is less talked about than sildenafil and tadalafil, but it works in the same way and can be a good option for some men, so it is worth understanding how it compares and how to use it.

This guide explains what vardenafil is, how it works, its doses and timing, the side effects and the all-important nitrates contraindication. It draws on the UK Summary of Product Characteristics, the NHS and NICE, and is general information rather than personal medical advice.

What vardenafil is

Vardenafil is a PDE5 inhibitor licensed for erectile dysfunction in adult men, and it is the active substance in Levitra; it is also available as generic vardenafil ¹. It belongs to the same family of medicines as sildenafil, tadalafil and avanafil, and works through the same mechanism ¹.

Like the others, it is intended to help a man get and keep an erection firm enough for satisfactory sexual activity, in the context of sexual arousal ¹. It treats the symptom of erectile dysfunction rather than its underlying cause ¹².

Vardenafil sits in the middle of the group in terms of how quickly it works and how long it lasts: faster and shorter than tadalafil, broadly similar to sildenafil ¹. That makes it a reasonable alternative if another PDE5 inhibitor has not suited someone ¹³.

Because it is a prescription-only medicine, a clinician assesses whether it is suitable, taking account of your heart health, other medicines and any conditions that would make it unsafe ¹².

How it works

During sexual arousal, the body relaxes the blood vessels in the penis so that it fills with blood and becomes erect ¹. Vardenafil supports this by blocking the PDE5 enzyme, which helps the natural process work more effectively ¹.

Crucially, it works only when there is sexual stimulation ¹. It does not produce an erection on its own, and it does not increase desire or arousal; it supports the body's own response ¹.

This is identical in principle to the other PDE5 inhibitors ¹. The practical differences between them are about timing, duration, the effect of food and individual tolerability, rather than the underlying mechanism ¹³.

Understanding that it needs arousal to work helps set realistic expectations and judge whether it is helping ¹.

Doses and how to take it

Vardenafil is taken as needed, usually about 25 to 60 minutes before sexual activity, with the dose timed so it is working when wanted ¹. It is not a daily medicine ¹.

The usual starting dose is 10 mg, which a prescriber may increase to a maximum of 20 mg, or reduce to 5 mg, depending on how well it works and how well it is tolerated ¹. A lower dose may be used for people who are more sensitive to side effects, who are older, or who have certain conditions ¹.

It should not be taken more than once in 24 hours¹. A heavy, high-fat meal can delay how quickly it works, and alcohol can reduce its effectiveness and worsen side effects, so moderation helps ¹².

If the first attempt is not successful, that is common and does not necessarily mean it is the wrong medicine; it can take a few proper attempts, and stimulation is essential ¹. A prescriber can review the dose if needed ¹².

Considering treatment for erectile dysfunction? You can start an assessment with a Cloud Pharmacy clinician, who will review your medical history and confirm whether treatment is appropriate.

Side effects

The most common side effects of vardenafil are headache, flushing, a blocked or runny nose and indigestion¹. These are usually mild and reflect the medicine's effect on blood vessels, often settling as the body gets used to it ¹.

Less commonly, people can experience dizziness, back pain or visual effects ¹. As with the other PDE5 inhibitors, the product information lists a range of possible effects, most of which are uncommon ¹.

Seek emergency care for an erection lasting more than four hours (priapism), or for sudden loss of vision or hearing ¹. These are uncommon but need prompt action to avoid lasting harm ¹.

If side effects are troublesome, a prescriber may suggest a lower dose or a different option ¹². Most men who find vardenafil suits them tolerate it well ¹.

Nitrates and other key cautions

The most important safety rule is that vardenafil must never be combined with nitrates (such as GTN for angina), nicorandil or recreational 'poppers', because the combination can cause a dangerous drop in blood pressure ¹. This is an absolute contraindication ¹.

Alpha-blockers (used for blood pressure or prostate symptoms) need caution because of the blood-pressure-lowering effect, and some other medicines, including certain antifungals and HIV medicines, can raise vardenafil levels ¹. A prescriber needs your full medicine list ¹.

There are also heart-rhythm considerations specific to vardenafil, which is one reason a clinician assesses your heart health before prescribing it ¹. People with certain heart conditions may be advised to avoid it or use another option ¹.

These cautions are exactly why vardenafil is assessed before prescribing, and why honesty about your health and medicines matters ¹². Our guide on ED medication and nitrates covers the contraindication in detail ¹.

How vardenafil compares with the others

Vardenafil works the same way as the other PDE5 inhibitors but differs in the practical details ¹³. It acts within roughly half an hour to an hour and lasts a few hours, which is broadly similar to sildenafil and shorter than tadalafil's long window ¹.

For some men, one PDE5 inhibitor suits better than another, whether because of how it works for them or how they tolerate it, so vardenafil can be a useful alternative if sildenafil has not been ideal ¹³. There is no single best option for everyone ³.

Choosing between them is an individual decision based on how fast you want it to work, how long you want it to last, the effect of food, and tolerability, made with a prescriber ¹³. Our guide comparing the four PDE5 inhibitors sets them side by side ³.

The fact that there are several options is genuinely helpful, because it means a medicine can usually be found that suits you ¹³.

Getting vardenafil safely

Vardenafil is a prescription-only medicine, so it should be obtained through a registered pharmacy after a proper assessment, in person or via a regulated online service ¹². The assessment checks suitability, your heart health and your other medicines ¹.

Buying it from unregulated websites is risky, because the MHRA warns that fake ED medicines are common online and may be the wrong dose or contain harmful ingredients ⁴. A legitimate supply always comes with an assessment ²⁴.

If you think vardenafil might suit you, or another PDE5 inhibitor has not been ideal, you can start an assessment with a clinician to discuss whether it is appropriate and at what dose ¹².

And because persistent ED can signal an underlying condition such as diabetes, high blood pressure or heart disease, an assessment also helps make sure nothing important is being missed ²³.

Key points to remember

Vardenafil is an effective, well-established PDE5 inhibitor for erectile dysfunction, taken as needed before sex and adjusted between 5 mg and 20 mg with a prescriber ¹. It works only with stimulation and is not a daily medicine ¹.

Never combine it with nitrates, tell your prescriber about all your medicines and heart health, and know the red-flag symptoms of an erection lasting over four hours or sudden vision or hearing loss ¹. These keep an effective medicine safe to use ¹.

It is a useful alternative if another PDE5 inhibitor has not suited you, and the choice between the options is personal ¹³. A prescriber can help you find the one that fits ¹².

Needing a medicine for ED is common and nothing to feel awkward about, and a confidential assessment is a routine, sensible part of getting it safely ²³.

ED as a signal worth investigating

As with the other ED medicines, it is worth remembering that persistent erectile dysfunction can be an early signal of an underlying condition ²³. The blood-vessel health behind erections overlaps with general cardiovascular health, so conditions such as diabetes, high blood pressure and heart disease can show up first as ED ³.

Psychological factors, stress, poor sleep, alcohol and some medicines can also contribute, which is why ED is often best understood in the round rather than only at the moment of sex ²³. Vardenafil treating the symptom does not remove the value of understanding the cause ².

This is why an assessment for vardenafil does more than authorise a prescription: it is a chance to look at your wider health and check that nothing important is being missed ²³. The NHS encourages seeing a clinician if ED keeps happening ².

So the most useful approach is to pair effective symptom relief with a proper look at why the ED is occurring, which an assessment can do at the same time ²³. That way vardenafil helps with the symptom while a clinician keeps an eye on the bigger picture, which is the sensible balance for an ongoing problem ²³. If you think vardenafil might suit you, an assessment is the safe way to confirm it and to have that wider check at the same time ¹².

Frequently asked questions

What is vardenafil?

Vardenafil is a PDE5 inhibitor for erectile dysfunction, the active ingredient in Levitra ¹. It works the same way as sildenafil, tadalafil and avanafil, supporting an erection during sexual arousal ¹.

How and when do I take it?

As needed, about 25 to 60 minutes before sex, usually starting at 10 mg and adjusted between 5 mg and 20 mg, no more than once in 24 hours ¹. A heavy meal can delay onset and alcohol can reduce its effect ¹.

How does it compare with sildenafil and tadalafil?

It works the same way but acts within about half an hour to an hour and lasts a few hours, similar to sildenafil and shorter than tadalafil's long window ¹³. It can be a useful alternative if another option has not suited you ³.

Can I take it with nitrates?

No, never. Combining vardenafil with nitrates, nicorandil or 'poppers' can dangerously lower blood pressure and is an absolute contraindication ¹. There are also heart-rhythm cautions, so tell your prescriber your full health and medicine history ¹.

What are the common side effects?

Headache, flushing, a blocked or runny nose and indigestion are most common ¹. Seek emergency care for an erection lasting more than four hours, or sudden vision or hearing loss ¹.

How do I get vardenafil safely?

Through a registered pharmacy after a proper assessment, in person or via a regulated online service ¹². The MHRA warns fake ED medicines are common online, so avoid unregulated sellers ⁴.

Your next step

Vardenafil is a PDE5 inhibitor for erectile dysfunction, the active ingredient in Levitra, taken as needed about 25 to 60 minutes before sex and adjusted between 5 mg and 20 mg by response and tolerability. It works only with sexual stimulation, must never be combined with nitrates, and common side effects such as headache and flushing are usually mild, while an erection lasting over four hours or sudden vision or hearing loss need emergency care.

It works much like sildenafil and tadalafil but differs in timing and duration, and can be a useful alternative if another option has not suited you, since the choice between the four PDE5 inhibitors is personal. Get it only through a registered pharmacy after a proper assessment, which also checks your heart health and whether the ED needs further investigation. If you think vardenafil might suit you, you can start an assessment with a Cloud Pharmacy clinician to confirm whether it is appropriate and at what dose.

Disclaimer

This guide is for general information only and does not constitute medical advice, diagnosis or treatment. The information here describes general clinical context based on UK regulatory sources cited above; it is not a recommendation for any specific medicine or treatment, which can only be made by a prescriber following individual assessment.

If you are considering treatment, speak to your GP or pharmacist, or arrange a consultation with a Cloud Pharmacy clinician. Prescription-only medicines are issued only after clinical assessment and where appropriate.

If you experience side effects from any medicine, you can report them through the Yellow Card scheme at yellowcard.mhra.gov.uk.

References

1. Vardenafil SmPC 4.1/4.2/4.3/4.4/4.5/4.8/5.1 (PDE5 inhibitor for ED; as needed ~25-60 min before sex; start 10 mg, range 5-20 mg, max once/24h; works only with stimulation; food/alcohol; common side effects; nitrates absolute contraindication incl. nicorandil/amyl nitrite; alpha-blocker and CYP3A4 interactions; QT/heart-rhythm cautions; priapism >4h, vision/hearing loss)
2. NHS erectile dysfunction (assessment; persistent ED warrants review; ED can signal underlying conditions; general framing)
3. NICE CKS erectile dysfunction (PDE5 inhibitor class; choosing between agents; no single best option)
4. MHRA #FakeMeds (fake ED medicines common online; buy only from registered pharmacies)