Tadalafil vs vardenafil: which ED treatment is right for you?
- Compare onset, duration, dosing, food interaction, and UK availability
- How the two medicines differ pharmacologically
- Duration of action and how they differ
- Compare side effects and what the SmPC data shows
- Who suits each treatment
- UK availability and cost: What to expect from each route
- Head-to-head comparison: Tadalafil vs Vardenafil
- How they work: Shared mechanism, different selectivity
- Duration of action: The practical difference
- Side effect profiles: similarities and key differences
- Who is Tadalafil more appropriate for?
- Who is Vardenafil better for?
- Food interactions: A practical consideration
- Availability and prescribing in the UK
- Cost comparison
- Final thoughts
Head-to-head comparison: Tadalafil vs Vardenafil
Both medicines share the same class and core mechanism, but differ in ways that matter in practice. The table below sets out the key differences side by side.
| Feature | Tadalafil | Vardenafil |
|---|---|---|
| Brand name equivalent | Cialis | Levitra |
| Standard starting dose | 10 mg on demand | 10 mg on demand |
| Available doses | 2.5 mg, 5 mg, 10 mg, 20 mg | 5 mg, 10 mg, 20 mg |
| Daily dosing option | Yes (2.5 mg, 5 mg) | No |
| Onset of action | 30 minutes to 2 hours | 25 to 60 minutes |
| Duration of action | Up to 36 hours | 4 to 6 hours |
| Half-life | ~17.5 hours | 4 to 5 hours |
| Affected by high-fat food | Minimally | Yes, onset may be delayed |
| Visual side effects | Less common | More common than tadalafil |
| Back pain and muscle aches | More common | Less common |
| Generic available in UK | Yes | Yes |
| Daily dosing option | Yes | No |
Sources: Tadalafil and vardenafil Summaries of Product Characteristics, medicines.org.uk.
How they work: Shared mechanism, different selectivity
Both Tadalafil and Vardenafil belong to the PDE5 inhibitor class and work through the same basic mechanism. During sexual arousal, the body releases nitric oxide into penile tissue, which triggers the production of cyclic GMP (cGMP). cGMP relaxes smooth muscle in the blood vessel walls of the penis, allowing blood to flow in and produce an erection. Both medicines block PDE5, the enzyme responsible for breaking down cGMP, allowing the erection response to work more effectively.
Where they differ is in their selectivity for PDE enzymes beyond PDE5, and in their pharmacokinetic profiles, which produce the differences in duration, side effects, and practical use, which we will cover throughout this guide.
Good to know
Neither Tadalafil nor Vardenafil cause an erection automatically. Sexual stimulation is required for either medicine to produce its intended effect.
Duration of action: The practical difference
The most clinically significant difference between the two medicines is how long they remain active.
Vardenafil has a half-life of four to five hours, broadly similar to Sildenafil, and a duration of action of approximately four to six hours. Like Sildenafil, it requires planning around the timing of the dose relative to sexual activity.
Tadalafil has a half-life of approximately 17.5 hours and can remain active for up to 36 hours after a single on-demand dose. This extended window removes the need to plan precisely around taking a tablet, which many men find meaningfully reduces performance-related pressure.
For men who value spontaneity or who find the timing requirement of shorter-acting medicines a source of stress, Tadalafil's duration is a clinically meaningful advantage. For men who prefer a medicine that clears the system relatively quickly, Vardenafil's shorter action may be preferable.
Good to know
Tadalafil is the only PDE5 inhibitor with a licensed daily low-dose regimen (2.5 mg and 5 mg). This option maintains a consistent background level of the drug without any timing requirement, which some men find the most convenient approach of all. Vardenafil does not have an equivalent daily dosing option.
Side effect profiles: similarities and key differences
As both medicines share the same core mechanism, their side effect profiles overlap significantly. Headache, flushing, nasal congestion, indigestion, and dizziness are common to both.
The clinically meaningful differences lie in two areas: back pain and visual effects.
Back pain and muscle aches
Back pain and muscle aches are more frequently reported with Tadalafil than with Vardenafil. This is thought to be related to Tadalafil's inhibition of PDE11, an enzyme found in skeletal muscle. Vardenafil has lower activity against PDE11, which may explain why this side effect is less commonly associated with it.
For men who find back pain or muscle aches a significant issue on Tadalafil, Vardenafil may be better tolerated on this dimension.
Visual side effects
Both Tadalafil and Vardenafil inhibit PDE6, an enzyme found in the retina, which is responsible for the visual disturbances (blue-green colour tinge, increased light sensitivity, blurred vision) reported with PDE5 inhibitors. Tadalafil has lower selectivity for PDE6 relative to PDE5 than Vardenafil, meaning visual side effects are less commonly associated with Tadalafil.
For men who experience visual disturbances on Sildenafil or Vardenafil, Tadalafil may be better tolerated. Here is a breakdown of each side effect and its likelihood.
| Side effect | Tadalafil | Vardenafil |
|---|---|---|
| Headache | Very common | Very common |
| Flushing | Common | Common |
| Nasal congestion | Common | Common |
| Indigestion | Common | Common |
| Dizziness | Common | Common |
| Back pain and muscle aches | More common | Less common |
| Visual disturbances | Less common | More common |
| Priapism | Rare | Rare |
| Sudden vision or hearing loss | Rare | Rare |
Sources: Tadalafil and Vardenafil - Summaries of Product Characteristics,
Important!
Both medicines share the same absolute contraindication with nitrate medicines. Neither Tadalafil nor Vardenafil should ever be taken alongside nitrates of any form, including GTN spray, isosorbide mononitrate, or isosorbide dinitrate. The combination can cause a severe and potentially life-threatening drop in blood pressure.
Who is Tadalafil more appropriate for?
Based on the clinical evidence and the practical differences between the two medicines, Tadalafil tends to suit men who:
- Value spontaneity and prefer not to plan precisely around taking a tablet before sexual activity
- Have sex frequently and would benefit from a daily low-dose option
- Experience visual disturbances with shorter-acting PDE5 inhibitors
- Also have symptoms of benign prostatic hyperplasia (BPH), as daily tadalafil 5 mg is licensed for both conditions simultaneously
- Are not troubled by back pain or muscle aches, or find these mild and tolerable
Who is Vardenafil better for?
Vardenafil may be the more appropriate choice for men who:
- Prefer a medicine that clears the system relatively quickly, for example those who prefer a shorter window of action
- Experience significant back pain or muscle aches on Tadalafil
- Have a predictable pattern of sexual activity and are comfortable planning around a tablet taken 30 to 60 minutes beforehand
- Have tried Tadalafil and found it insufficiently effective or poorly tolerated, as individual response to PDE5 inhibitors varies
The recommended starting dose of Vardenafil is 10 mg taken approximately 25 to 60 minutes before sexual activity. Based on efficacy and tolerability, the dose may be increased to 20 mg or decreased to 5 mg. The maximum recommended dosing frequency is once per day.
Good to know
If one PDE5 inhibitor has not worked well for you, it is worth trying another before concluding that medication is not the right approach. Individual response to medicines within the same class varies, and a switch rather than a discontinuation is often the better next step.
Food interactions: A practical consideration
Both tadalafil and vardenafil can be taken with or without food, but high-fat meals affect each medicine slightly differently.
Vardenafil can be taken with or without food, but the onset of activity may be delayed if taken with a high-fat meal. This is broadly similar to sildenafil's food interaction, though generally considered less pronounced.
Tadalafil is not meaningfully affected by food. A high-fat meal does not significantly delay absorption or reduce peak blood levels, making it the more practical option for men who typically take ED medication in the context of a meal or social occasion.
Availability and prescribing in the UK
Both Tadalafil and Vardenafil are prescription-only medicines available in the UK via NHS prescription or private online clinic.
NHS access: Both medicines can be prescribed on the NHS for ED where they meet NICE prescribing criteria. Generic tadalafil is typically the more commonly prescribed option on the NHS, reflecting its wider licensed indications and cost-effectiveness profile. Vardenafil is available on the NHS but is prescribed less frequently than tadalafil or sildenafil in most clinical settings.
Private prescription: Both are available from GPhC-registered online clinics following a medical assessment by a UK-registered prescriber. Tadalafil tends to be more widely stocked and readily available at private providers than Vardenafil, which is worth considering if supply consistency is important to you.
Branded vs generic: Tadalafil (generic for Cialis) has been available since 2018. Generic Vardenafil (Levitra patent expired in 2018) is also available, though branded Levitra is less commonly encountered in UK private prescribing than branded Cialis.
Cost comparison
Both medicines are available as generics in the UK, which makes them considerably more affordable than their branded equivalents. As a general guide:
- Generic Tadalafil and generic Vardenafil are broadly comparable in cost per tablet at equivalent doses from most UK providers
- Tadalafil's daily dosing option (2.5 mg or 5 mg) may work out cost-effective for men who use it frequently, compared to on-demand dosing at higher strengths
- Branded Levitra (Vardenafil) and branded Cialis (Tadalafil) carry a significant premium over generic versions without any clinical benefit
Always compare total cost including consultation and delivery when evaluating providers, not just the headline tablet price.
Final thoughts
Tadalafil and Vardenafil are both effective, well-established treatments for erectile dysfunction. For most men, the choice comes down to two practical questions: how important is spontaneity, and which side effect profile is more acceptable?
Tadalafil's extended duration and daily dosing option make it the more flexible choice for the majority of men. Vardenafil offers a shorter, more contained action window and may suit those who experience back pain on tadalafil or who prefer a medicine that clears the system more quickly. Neither is the right answer for everyone, and individual response varies enough that trying both under prescriber guidance is a reasonable approach if the first choice does not produce the desired result.
FAQ
Is Tadalafil or Vardenafil better for ED?
Neither is objectively better. Both are effective PDE5 inhibitors with similar overall efficacy in clinical trials. The meaningful differences are in duration of action, side effect profile, and dosing flexibility. Tadalafil's extended duration and daily dosing option make it the more convenient choice for many men; Vardenafil may suit those who prefer a shorter action window or experience back pain on tadalafil.
Which lasts longer, tadalafil or vardenafil?
Tadalafil lasts significantly longer. A single on-demand dose can remain active for up to 36 hours, compared to four to six hours for vardenafil. This is the most clinically significant practical difference between the two medicines.
Does Vardenafil have fewer side effects than Tadalafil?
Neither medicine is clearly better tolerated across all measures. Back pain and muscle aches are more commonly associated with Tadalafil; visual disturbances are more commonly associated with Vardenafil. For individual side effects, one may be better tolerated than the other depending on personal response.
Can I switch from tadalafil to vardenafil?
Yes, switching is possible under prescriber guidance. Your prescriber will advise on the appropriate starting dose for the new medicine based on your treatment history. There is no evidence of harmful interactions from switching between PDE5 inhibitors.
Is Vardenafil available on the NHS in the UK?
Yes, Vardenafil can be prescribed on the NHS for ED where it meets prescribing criteria. However, generic Tadalafil and Sildenafil are more commonly prescribed in NHS settings. Vardenafil is available via private prescription from GPhC-registered providers.
Does Tadalafil or Vardenafil work faster?
Vardenafil has a slightly faster onset in some men, with the SmPC recommending it be taken 25 to 60 minutes before sexual activity. Tadalafil's onset is 30 minutes to two hours. For most men the practical difference is modest, but Vardenafil may be marginally faster for those who want the shortest possible gap between taking the tablet and sexual activity.
The DoktorABC medical advisory board
Dr. Roland Ruiken
Medical advisor, Norway
Dr. Viktor Simunovic
Medical advisor, Croatia