This guide compares avanafil (Spedra) and tadalafil (Cialis): onset, duration, food, side effects and the safety rules they share. It draws on the UK Summary of Product Characteristics for each and on the NHS and NICE, and is general information rather than personal advice.
What each one is
Spedra is the brand name for avanafil, a more recently introduced PDE5 inhibitor known for its fast onset1. It comes in 50 mg, 100 mg and 200 mg strengths.
Cialis is the brand name for tadalafil, the long-acting PDE5 inhibitor 2. Its defining feature is duration: a single on-demand dose can work across a much longer window than the others.
Both are the same kind of medicine and work the same way, relaxing the blood vessels of the penis so an erection can occur with sexual arousal 12. Neither works without stimulation. The real difference between them is timing.
Onset: how fast Spedra works
Spedra is designed to work quickly, and is taken about 15 to 30 minutes before sex 1. That fast onset is its main selling point: less waiting between taking the tablet and being ready.
This can suit men who value being able to act closer to the moment, rather than planning an hour ahead 1. It is a practical advantage for spontaneity within a single occasion.
It is worth being factual rather than absolute about this: 'fast-acting' describes how soon it can work, not that it is more effective 13. The medicines are broadly similar in how well they work; they differ mainly in timing.
Duration: how long Cialis lasts
Cialis works at the other end of the spectrum: a single on-demand dose lasts up to about 36 hours2. That long window is why tadalafil is sometimes called the 'weekend' option.
It means you can take it well ahead and not have to time things precisely, which removes the pressure of a tight window 2. For many men, that flexibility is the whole appeal.
As with all these medicines, the duration describes the window during which an erection can be achieved with arousal, not a continuous erection 2. Both Spedra and Cialis are taken no more than once in 24 hours.
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.
Food and alcohol
Tadalafil's onset is not significantly affected by food, so Cialis can be taken with or without a meal 2. That is convenient around eating out.
Avanafil can be taken with or without food too, though a heavy, high-fat meal may slow its onset a little, which matters more because its appeal is speed 1. Taking it on a lighter stomach helps preserve the fast onset.
For both, alcohol can reduce the effect and worsen side effects such as flushing and low blood pressure, so moderation helps 12. Heavy drinking around a dose is best avoided whichever you choose.
Side effects compared
Both share the typical PDE5 inhibitor side effects: headache, flushing, nasal congestion and indigestion 12. These are usually mild and tend to settle.
Tadalafil is a little more associated with back pain and muscle aches, linked to it staying in the body longer 2. Avanafil's shorter action means its side effects tend to be shorter-lived too 1. Neither difference is a strong reason to prefer one.
Both carry the same red flags: an erection lasting more than four hours, or sudden loss of vision or hearing, need emergency care 12. These are rare but important regardless of which you take.
The safety rule they share: nitrates
Both Spedra and Cialis must never be taken with nitrates12. Nitrates include angina medicines such as glyceryl trinitrate and isosorbide mononitrate, as well as nicorandil and recreational 'poppers'.
Combining any PDE5 inhibitor with a nitrate can cause a sudden, dangerous drop in blood pressure 12. This is an absolute contraindication for both, not a relative caution, and is a key reason ED medicines are supplied after an assessment.
There is also caution around alpha-blockers and certain other medicines, which is why telling a prescriber everything you take matters 12. Tadalafil's long duration extends the period over which these cautions apply.
So which should you choose?
If fast onset matters most to you, Spedra's ability to work in about 15 to 30 minutes is the draw 1. It suits men who would rather act close to the moment than plan ahead.
If a long window and not having to time things matters more, Cialis's up-to-36-hour duration is the obvious fit 2. For spontaneity across a weekend, tadalafil leads.
Both are equally legitimate, the same kind of medicine, and trying one and switching is normal 3. A prescriber can help you weigh onset against duration and match the medicine and dose to you 3.
Getting either safely
Both Spedra and Cialis are prescription medicines, supplied after an assessment that checks suitability, the nitrates contraindication and the wider picture 123. That assessment is part of using them safely.
Erectile dysfunction can be an early sign of conditions such as heart disease or diabetes, so the assessment is not just a formality 3. It is a chance to look at your overall health, not only to supply a tablet.
Buy only from a registered pharmacy: the MHRA warns that fake ED medicines are common online 4. You can start an assessment with a Cloud Pharmacy clinician to decide between fast onset and long duration, and to confirm which is right for you 21.
How they fit into everyday life
Beyond the clinical detail, the two medicines fit into life quite differently, and that is often what really decides the choice 12. Spedra suits a more in-the-moment approach, where you take a tablet shortly before sex and do not want to plan far ahead.
Cialis suits men who would rather not think about timing at all2. Taken ahead of a weekend or a few days, its long window means a single dose can cover more than one occasion, which many find removes the pressure of a tight schedule.
Neither pattern is better; they reflect different lives and preferences 3. Someone whose sex life is spontaneous but occasional may prefer the fast tablet, while someone in a relationship where sex happens across a weekend may prefer the long window.
It is also worth remembering that both still need sexual arousal to work, so neither removes the need for the right moment; they simply change how far ahead you take the tablet 12.
Switching and finding the right fit
Because Spedra and Cialis are the same kind of medicine, switching between them is straightforward if your first choice does not suit 12. Many men try one, see how it fits, and move to the other, which is a normal part of finding the right treatment.
You should not take both at once, and you should keep to one dose in any 24 hours, but trying one on some occasions and the other on others, under a prescriber's guidance, is reasonable 12. The aim is the medicine that fits your life with the fewest side effects.
If neither suits, the other PDE5 inhibitors, sildenafil and vardenafil, are also options, so the choice is wider than just these two 3. A prescriber can talk you through the full set rather than limiting you to one.
Give each a fair trial under good conditions before judging it, since a single disappointing occasion is rarely a reliable verdict 3. A short review with a clinician usually sorts out whether to adjust the dose, switch the medicine, or look more closely at the wider picture.
A quick recap of the choice
If it helps to simplify: both Spedra and Cialis are prescription PDE5 inhibitors that work the same way and only with arousal, and both share the same red flags and the absolute nitrates rule 12. On the essentials they are alike.
The single distinction that matters is timing: Spedra's fast onset of around 15 to 30 minutes against Cialis's window of up to about 36 hours 12. Almost everything else about the decision follows from that one difference.
Choose fast onset if you would rather act close to the moment, and the long window if you would rather take a tablet ahead and not think about timing 12. Both are legitimate, and switching is easy if your first choice does not suit.
If the choice still feels unclear, that is exactly what an assessment is for, and a prescriber can weigh onset against duration with your health in mind 3. There is no wrong answer here, only the fit that suits your life best.
And remember the choice is not limited to these two: sildenafil and vardenafil round out the four PDE5 inhibitors, so if neither Spedra nor Cialis is ideal, there are still options to consider 3.
Frequently asked questions
What is the main difference between Spedra and Cialis?
Onset versus duration. Spedra (avanafil) is fast-acting, taken about 15-30 minutes before sex; Cialis (tadalafil) lasts up to about 36 hours 12. Both are the same kind of medicine and work only with arousal.Is Spedra faster than Cialis?
Yes, avanafil is designed to work quickly, in about 15-30 minutes, whereas tadalafil is usually taken at least 30 minutes before but is valued for its long window rather than speed 12. Faster onset does not mean more effective.Which lasts longer?
Cialis, by a wide margin: up to about 36 hours from a single dose, compared with Spedra's shorter action 12. Neither gives a continuous erection; the time is the window during which one can be achieved with arousal.Can I take either with nitrates?
No, never. Both must never be combined with nitrates, nicorandil or 'poppers', as this can cause a dangerous drop in blood pressure 12. This is an absolute rule for both.Do their side effects differ?
They overlap (headache, flushing, congestion), but tadalafil is a little more linked with back and muscle pain, while avanafil's effects tend to be shorter-lived 12. Both share the priapism and sudden vision or hearing loss red flags.How do I choose?
Pick fast onset (Spedra) or a long window (Cialis) according to what suits your life, and a prescriber can help you weigh it 123. Both are prescription medicines supplied after an assessment.Your next step
Spedra and Cialis are both PDE5 inhibitors that work the same way, so the choice between them is about timing: avanafil's fast onset of around 15 to 30 minutes versus tadalafil's up-to-36-hour window. Faster onset does not mean more effective, and a longer window does not either; they simply suit different preferences.
Their side effects overlap, with tadalafil a little more linked to back and muscle pain and avanafil's effects shorter-lived, and both share the same red flags and the absolute rule never to combine them with nitrates. Both are equally legitimate, and trying one and switching is a normal part of finding the right fit.
Because both are prescription medicines, they are supplied after an assessment that checks suitability and the wider picture, since ED can be an early sign of other conditions. Buy only from a registered pharmacy, and you can start an assessment with a Cloud Pharmacy clinician to weigh fast onset against long duration and confirm which is right for you.
Whichever you lean towards, the reassuring point is that both are well-established, effective medicines, and the decision is more about convenience and lifestyle than about one being far superior. Getting the choice right, and using it correctly, matters more than which of the two you start with.
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
- Spedra (avanafil) SmPC 4.1/4.2/4.3/4.4/4.5/4.8 (PDE5 inhibitor; taken ~15-30 min before sex; fast onset; with or without food, high-fat meal may slow onset; works only with stimulation; max once/day; headache/flushing/nasal side effects; priapism/vision/hearing red flags; nitrates absolute contraindication; alpha-blocker caution)
- Cialis (tadalafil) SmPC 4.1/4.2/4.3/4.4/4.5/4.8 (PDE5 inhibitor; >=30 min before; onset not significantly affected by food; up to ~36-hour duration; works only with stimulation; max once/day; back/muscle pain and other side effects; priapism/vision/hearing red flags; nitrates absolute contraindication; alpha-blocker caution)
- NICE CKS erectile dysfunction (PDE5 inhibitors broadly similar efficacy; choice on duration/onset/patient preference; assessment; ED can signal underlying conditions)
- MHRA #FakeMeds (fake ED medicines common online; buy only from registered pharmacies)
