Vardenafil is the generic active ingredient in the ED medication formerly sold under the brand name Levitra, which has been discontinued in the US. It has an 80% success rate for helping you get and stay hard.
But vardenafil side effects can and do happen. It’s good to know what to look out for before you take it. If you have any questions about the side effects or its interactions with other medications, you’re in the right place.
Last updated on Sep 19, 2025.
Vardenafil is a PDE5 inhibitor. PDE5 is an enzyme in the body that causes blood vessels to constrict (narrow). By limiting the activity of PDE5, vardenafil encourages blood vessels to dilate (open up).
If you have ED, vardenafil allows blood to more easily enter two shaft-like columns of tissue in the penis when you’re sexually aroused, allowing you to get an erection. However, vardenafil doesn’t just act on the blood vessels in your penis but throughout your body.
So, most adverse effects are a result of a change in blood pressure. Vardenafil side effects are not normally something to worry about and will wear off as the body eliminates it from your system after a few hours.
If you have a history of low blood pressure or are already taking medication to lower your blood pressure, let your prescriber know as in these cases vardenafil may not be the best ED treatment for you.
Broken down into common, uncommon and rare, here are the side effects some men may experience when beginning treatment with vardenafil.
Whilst most men won’t experience a headache, it is still considered a very common side effect – occurring in about 25% of users. It normally happens when beginning treatment and most men find it goes away after the first couple of uses. Vardenafil isn’t alone in this, with most ED pills initially causing the occasional headache at first.
It happens because PDE5 inhibitors, like vardenafil,encourage your blood vessels to widen, and therefore blood flow changes in the brain. The result is headaches ranging from a mild, dull pain to migraines and cluster headaches. Headaches often begin less than an hour after you take vardenafil but can also happen after the medication’s effects have worn off, potentially affecting sleep.
It’s possible to treat headaches from vardenafil, limiting their intensity and how long they last. A few ways to avoid a headache include staying hydrated, avoiding alcohol, and eating a small meal or snack with your medication. If you frequently experience headaches after taking vardenafil, your doctor might suggest acetaminophen (the active ingredient in Tylenol), which won’t interact with vardenafil, and will be safe to use at the recommended dose.
If you experience bad headaches or migraines and feel as though they’re just not tolerable, or they’re negatively affecting your overall sexual experience, ask your prescriber about lowering your dose as data shows that headaches are linked to higher doses.
Common side effects may affect up to 1 in 10 people and include:
Uncommon side effects may affect up to 1 in 100 people. These include:
Rare side effects may affect up to 1 in 1,000 people, and include:
Let your prescriber know if you experience any side effects when taking Vardenafil and they will be able to discuss them with you in detail. Together you and your clinician will be able to evaluate whether you should continue with your prescription, lower your dose of vardenafil, or change medication. You can also report side effects directly to the FDA through their MedWatch program. This helps the FDA track medication safely.
Many men with ED find that milder side effects stop after several goes with Levitra. This is because your body can become less sensitive over time. However, if you experience side effects such as chest pain, altered heartbeat, seizures, swelling, breathlessness or an erection that lasts more than four hours (priapism), these require immediate medical attention and you should go to the hospital right away.
Once you receive your prescription, remember to read the patient information leaflet. Yes, it’s long and you may feel you’ve read up on everything there is to know, but the leaflet will give you instructions on how best to take Vardenafil, and it’s good to have that in front of you in black and white.
If you’re not taking any other medications which are known to interact with vardenafil the main thing to avoid will be grapefruit juice. Grapefruit juice can enhance the effects of vardenafil, increasing the chance of side effects, and so it’s a good idea to avoid it.
The first step you can take to keep your risk of side effects as low as possible will be at your initial consultation. Ensure you give your prescriber your full medical history including any medication you take or medical conditions you may have.
Some medication and medical conditions will mean that Levitra isn’t the best ED treatment for you, your clinician will know what these are. Giving them all the information you can allows them to make the best decision for you and will lower the chance of you experiencing any side effects from your treatment.
If you do experience side effects after you begin treatment, let your doctor know, they may consider lowering your dose or switching you to a different ED medication.
Vardenafil may interact with nitrate drugs, antihypertensives and alpha-blockers, which lower blood pressure. It’s important to let your prescriber know at your initial consultation if you take any of these medications as it may mean that Vardenafil isn’t the best option for you.
Other vardenafil interactions include antidepressants, antibiotics, antifungals, medications for a prostate disorder and HIV/AIDS medicine. Again let your prescriber know if you take any of these before beginning treatment with Vardenafil and let them know if you start taking them once you’ve already begun treatment.
There are a few pre-existing conditions which may mean your doctor will need to closely monitor your progress when being treated with Vardenafil. Or they may indicate a lower dosage starting point. These include:
If any of the following apply to you it may be that you cannot take Vardenafil, so you must tell your prescriber at your consultation:
If you’re allergic to vardenafil or any other ingredients contained in Vardenafil you shouldn’t use it. Signs of an allergic reaction include a rash, itching, swollen face, swollen lips and shortness of breath, so if you experience any of these let your doctor know immediately.
Vardenafil is not approved for men under 18 years old and may also not be suitable for men over 75 years old; your clinician will be able to judge if Vardenafil is suitable for you. If you take any medications that may interact with vardenafil, such as nitrate drugs for chest pain, then it’s important to let your prescriber know as these taken with Vardenafil can dangerously affect blood pressure. Again, it may be the case that you shouldn’t use Vardenafil and another ED treatment will be more suitable.
Let your clinician know. If you’re prescribed a new medication that you weren’t taking when you first started with Vardenafil it may interact with it. Equally, if your health changes, discuss this with them too.
Your prescriber will be able to judge whether Vardenafil is still right for you, whether lowering your dose may be an option or whether a different ED treatment would be better.
The Efficacy and Safety of Flexible-Dose Vardenafil (Levitra®) in a Broad Population of European Men. European Urology, 45(5), 634-641.
Comparison of clinical trials with sildenafil, vardenafil and tadalafil in erectile dysfunction. Expert opinion on pharmacotherapy. 6(1): 75–84.
Sildenafil can induce the onset of a cluster headache bout. Canadian Urological Association journal = Journal de l'Association des urologues du Canada. 8(5-6): E378–E380.
Last updated on Sep 19, 2025.
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