Which of the three is strongest if I just want the best tablet?
Three cards, one Dublin floor, no podium
A match file using this clinic's locks. Not three monographs stapled together. No winner at sign-out.
Matching starts with this site's ink, not with a magazine winner. Cialis on this floor is the 2.5-20 mg labeled ladder. Viagra is the 50 mg usual start. Levitra is 5 or 10, with 20 waiting offstage. If a comparison uses different greeting milligrams, it is a different desk.
All three hold PDE5 so cGMP lasts longer after nitric oxide from arousal. None of them invents desire. None of them is safe with a nitrate or with riociguat. Shared class, three clocks.
I will not end this study with a champion. Men who need a champion are usually shopping. Men who need a match bring a nitrate history, a meal habit, a prostate complaint, a QT drug, and how often sex actually happens. That file decides. Not a league table.
Avanafil exists in the wider class and is not on this Dublin floor. I will not drag it in to pad a four-way chart. Three locks. Three clocks. That is the study.
Matching a man to a card, not a brand
Frequent or unplanned sex, or a real prostate complaint, pulls toward tadalafil's 5 mg daily door. Sparse nights and a wish to swallow only then pull toward a tadalafil 10-to-20 once card or toward a short evening tool.
A man who eats late and hates clocks often does better on tadalafil even if he liked the idea of a 50 mg diamond. A man already comfortable with a one-hour, empty-ish plate can stay on sildenafil 50 mg. A man whose list is QT-clean and who failed a diamond on haze may try vardenafil 10 mg - or 5 mg if he is older or alpha-blocked.
Cost talk comes after the match, not before the work-up. Generic prices move. I will not crown the cheapest card as the best card. The failure-first study still sits upstream of every lock on this table.
Older men collect more than one reason to start low: clearance, alpha-blockers, a longer QT, a softer pressure floor. That is not a reason to pick 'the weakest brand.' It is a reason to pick the lock that still has a labeled low greeting - vardenafil 5 mg, sildenafil 25 mg, tadalafil 2.5 or 5 - after the list is clean.
Who cares about the plate, who does not
Tadalafil does not care about the plate. That is a genuine matching gift for men who will not time dinner. Sildenafil loses speed and peak height after a fatty meal. Vardenafil film-coated tablets may be taken with or without food, though a heavy plate can still blunt the hour.
Ward-round the last failed swallow before you switch molecules. A 50 mg diamond after a steak is not proof sildenafil is weak. It may be proof the plate was the variable. Switching to tadalafil for food indifference is a fair match. Switching because a dinner trial was sloppy is not.
Alcohol is a shared hypotensive add-on, not a tie-breaker. Large drink plus any of the three cards is a softer pressure floor. I do not use that as a reason to crown a brand.
Grapefruit is a sildenafil-and-vardenafil footnote more than a tadalafil headline. Weak 3A4 gut hold. I still ask, because men treat juice as water. It will not pick a winner. It can make a 50 mg diamond sit higher than the chart assumed.
Colour haze, back ache, a QT tick
Sildenafil carries the loudest PDE6 colour story. Vardenafil sits nearer than marketing likes, quieter than the diamond for many men, still not zero. Tadalafil barely touches PDE6 and instead brings PDE11-linked back and muscle ache in a subset, often a day later.
Only vardenafil among these three makes me open a QT file as a first-pass habit. Congenital long-QT or Class IA/III drugs steer me off that card. The other two are not toys in a long-QT clinic either, but the Levitra ink is the one that names the thorough-QT numbers.
Headache and flush are class noise. They do not pick a winner. If they dominate, the first move is often a lower count on the same card, not a brand hop.
Hearing a sudden drop, even rare, is a class stop. I will not assign it to one lock to settle an argument. Stop the tablet. Get seen. Then reopen the match.
Half-lives that refuse to sit in one box
Seventeen-and-a-half hours versus about four hours is the only comparison that changes a life. Tadalafil can be a daily strip or a weekend once card because it stays. Sildenafil and vardenafil are evening tools. Asking which is stronger is usually a way of avoiding that clock.
Onset stories overlap more than brands admit. Fasted sildenafil can peak near an hour. Vardenafil's median Tmax is also about an hour. Tadalafil's peak is nearer two hours but the tail is the feature. A man who needs a short, dated evening and a man who needs no date are not in the same race.
Daily low-dose is a tadalafil room only, for ED, on this floor. Do not invent a daily Viagra 50 mg strip from first principles. The half-life will not hold a flat background the same way.
Weekend lore still collapses the three clocks into one nickname. A Friday diamond is gone by Saturday lunch. A Friday 20 mg tadalafil swallow can still be useful Sunday morning. A Friday Levitra 10 mg sits with the diamond, not with the almond. Teach the clock. Do not teach a league.
Nitrate gaps that are not interchangeable
Match keys that beat a brand preference
- Active nitrate or riociguat - all three cards shut
- Need a daily strip or a BPH door - tadalafil 5 mg daily is the labeled room
- Need a QT-clean short card - do not pick vardenafil if Class IA/III is live
- Need food indifference - tadalafil; sildenafil wants a lighter plate
Every card shuts for active nitrates. The leftover clocks are not copies. Tadalafil wants at least 48 hours if a nitrate becomes necessary after a dose. Sildenafil discussions often use 24 hours as the pharmacokinetic hint. Vardenafil never wrote a safe interval. Copying one gap onto another card is a medication error.
Alpha-blockers need a stable background and a low greeting on all three, with vardenafil explicitly opening at 5 mg in that setting. CYP3A4 inhibitors cut each card differently - ritonavir plus sildenafil is a 25 mg / 48-hour cap; plus tadalafil daily is a 2.5 mg cap; plus vardenafil can be a 2.5 mg / 72-hour cap. Do not transfer a cut.
Priapism past four hours, sudden vision or hearing loss - shared stop signs. I will not spend a paragraph ranking emergencies.
Guanylate-cyclase stimulators shut the same tray as nitrates. Riociguat is the named one. Men with pulmonary-hypertension cards sometimes arrive with both a PAH tablet and a leftover ED diamond. That pairing is a stacked cGMP hit. I send them back to the clinic that owns the PAH file.
Read the locks before you rank anything
| Card on this floor | Lock we match | Typical clock | Special hold |
|---|---|---|---|
| Tadalafil (Cialis) | 2.5-20 mg ladder | t1/2 ~17.5 h; PRN window to 36 h | Nitrate gap 48 h; daily option |
| Sildenafil (Viagra) | 50 mg usual start | t1/2 ~4 h; 30 min-4 h window | High-fat delays peak ~60 min |
| Vardenafil (Levitra) | 5 mg or 10 mg | t1/2 ~4-5 h; ~60 min | QT line; no defined nitrate interval |
Tadalafil's lock is a range because the label itself is a range: daily 2.5 or 5, as-needed 10 that may become 20 or 5. This floor writes 2.5-20 so the strip and the once card stay in one glance. Details sit in the strip-versus-once study.
Sildenafil's lock is a single usual diamond. Twenty-five and 100 exist. They are not this site's greeting. The origin of that 50 mg habit is the angina-miss card.
Vardenafil's lock is a fork, not a peak. Five or ten after the QT line. Twenty is labeled and still not how we introduce the card. Selectivity ratios belong in the selectivity study, not in a podium paragraph.
Sign-out without a winner
Sign-out the three cards as locks: 2.5-20, 50 mg, 5-or-10. Shared enzyme. Shared nitrate shut. Different clocks, plates, off-targets, and leftover gaps. No podium.
Bring the list to a clinician who can see you. This floor matches rooms. It does not fill them.
Last Updated
From the postbag
Questions this study raised
Answered by Dr. Saoirse Byrne, MD · Internal medicine & clinical pharmacology
Comparison letters always want a winner. I send back a match. If that frustrates you, you wanted a shop, not a floor.
None of them wins that sentence. They inhibit the same enzyme. They differ in how long they stay, whether food moves the peak, which cousin enzyme they nudge, and which extra hold they carry. Best is a match to your nights, your plate, your nitrate drawer, and your rhythm drugs. Strongest is a sales word.
He liked Cialis 20 mg on holiday. Should he skip Viagra 50 mg entirely?
Not as a rule. A 20 mg once tadalafil swallow is a long-window room. A 50 mg sildenafil swallow is a short evening room. If holiday sex was unplanned and meals were heavy, of course the long, food-indifferent card felt kinder. If he wants a dated evening and a shorter stay, the diamond is still a fair card. Do not treat one good holiday as a lifetime ranking.
Can he keep Levitra 10 mg at home and Cialis 2.5 daily at the same time?
He should not stack two PDE5 cards. Daily tadalafil already occupies the enzyme. Adding vardenafil is stacked exposure - more flush, more pressure drop, a messier QT-and-nitrate file. Pick a room. If the strip is not enough, review the strip. Do not build a cocktail.
His friend says Levitra is more selective so it must be safer for the heart.
Selectivity over PDE6 and PDE11 is not a cardiac-safety trophy. Vardenafil is the one with a named QT tick and a Class IA/III avoid list. Shared nitrate danger sits on all three. Safer for the heart is a work-up sentence - pressure, symptoms, exercise capacity - not a ratio on a slide. Read the selectivity study if he wants the enzyme grid, not a halo.
We eat late. Is there any point trying the 50 mg diamond?
There is, if he will move the swallow away from the heavy plate or accept a later peak. High-fat meals delay sildenafil about an hour and cut the peak. If late dinners are non-negotiable and he hates waiting, tadalafil is the cleaner match. That is a plate match, not a brand loyalty.
He has BPH and ED. Do we still compare all three?
Compare less. Tadalafil 5 mg daily is the labeled two-door tablet. Sildenafil 50 mg and vardenafil 5 or 10 do not carry that prostate indication. You can still use a short card for ED alone, and treat flow another way, but the tidy match on this floor is the 5 mg strip - after nitrates and alpha-blocker stacking are sorted.
If a nitrate is needed after a tablet, which gap do I use?
Use the gap that belongs to the tablet he took. Tadalafil: at least 48 hours, then monitored care. Sildenafil: discussions often use 24 hours as the level-has-fallen hint, still not a home protocol. Vardenafil: no defined interval on the label. Never borrow Cialis's two days for a Levitra evening. And if nitrates are a standing plan, none of the three cards should have been opened.
We were quoted three different cash prices. Should we just take the cheapest lock?
Price after the match, not instead of it. A cheap 50 mg diamond is the wrong cheap if he needs a daily strip. A cheap 20 mg tadalafil is the wrong cheap if a QT drug already emptied the Levitra tray and he actually needed a short card. Ask a pharmacist for generic counts once the room is chosen. This desk does not fill and does not crown a bargain. If the work-up is still empty, even a bargain lock is premature.
Read these as teaching on a general point, not as a care plan for whoever asked. Anything specific to you belongs with a prescriber who can see your notes, bloods and full medicine list at once.