01 Section
Why this note holds 10, 25 and 20 together
Lift the three locks before you lift a brand story. Cialis 10 mg as needed, Viagra 25 mg and Levitra 20 mg sit on this Copenhagen shelf because those are the labelled strengths this domain already reviews one-by-one. They share an enzyme target. They do not share a clock, a meal rule, or the same written heart-rhythm caution.
The rest of each labelled ladder still exists. Cialis as-needed tablets also come as 5 mg and 20 mg. Viagra also comes as 50 mg and 100 mg. Levitra also comes as 5 mg and 10 mg, and 10 mg is the usual start on that label. This site does not pretend those strengths vanished. It holds one lock per medicine in the search line so three neighbouring notes do not all shout the same milligram.
Read the 10 mg weekend lock as the labelled as-needed start for tadalafil, not as a claim that 20 mg never happens. Read the 25 mg Viagra lock as a labelled tablet that the US label already treats as a cautious first strength in older men, in hepatic or severe renal impairment, and with strong CYP3A4 inhibitors. Read the 20 mg Levitra lock as the labelled ceiling, not as a boast that bigger milligrams beat the other two molecules.
A 2.5 mg or 5 mg morning tadalafil swallow is a different timetable on the same molecule. It belongs on the daily versus weekend guide, not as a hidden champion inside this comparison. Anyone hunting 'the best ED pill' is asking the wrong question. Best for whom? A man who eats late and wants Sunday morning covered is not the same reader as a man on sotalol.
02 Section
The QT caution that only the 20 mg Levitra lock prints
Vardenafil 10 mg and a supra-therapeutic 80 mg were studied in 59 healthy men against moxifloxacin 400 mg. Therapeutic and supra-therapeutic doses moved QTc in the same band as that active control. Adding another QT-active drug added more QTc. The label tells people with congenital QT prolongation, or on Class IA or Class III antiarrhythmics, to avoid vardenafil.
That study was not designed as a head-to-head trophy against Cialis or Viagra. It is a warning that sits on one label. Congenital long QT, or a Class IA or Class III antiarrhythmic (quinidine, procainamide, amiodarone, sotalol), is a reason to leave the vardenafil lock shut and look at the other two only if the class itself is allowed. 'Try a small Levitra' is not a workaround. This shelf holds 20 mg. The caution already applies at 10 mg.
Strong CYP3A4 inhibitors (ritonavir, ketoconazole, clarithromycin and others) raise levels of all three drugs. The Levitra label is especially strict because exposure can climb far enough that the QT discussion and the dose ceiling collide. Grapefruit is a weaker, messier version of the same enzyme story. None of this is a reason to pick a winner. It is a reason to bring the full list to the visit.
Tadalafil and sildenafil do not carry that same written 'avoid in congenital QT / Class IA or III' line. They still carry the nitrate ban, the riociguat ban, and their own CYP3A4 dose cuts. An ECG that closes vardenafil does not automatically open the other two if a nitrate is in the house. The longer vardenafil write-up is the 20 mg difference guide.
03 Section
What cost reviews means when we will not invent a dollar
People type 'cost reviews' when they want a winner with a price tag. This page will not invent a pharmacy dollar. GoodRx, a chain circular, or yesterday's cash card can move by Monday. A sourced caption belongs on a dated table. A guessed figure does not belong here.
Generic sildenafil is often the lowest cash line in US discount listings. Generic tadalafil is no longer the luxury outlier it was when only the brand existed. Brand Levitra left many US shelves; generic vardenafil is what a pharmacy actually fills. Those are category facts. They are not a receipt from this morning, and they are not a reason to type a made-up price into this note.
A 25 mg Viagra tablet can look cheap and still waste the evening if the meal is wrong. A 10 mg Cialis tablet can look dear per pill and still cover Friday night and Saturday morning from one swallow, which changes the per-occasion arithmetic. A 20 mg Levitra tablet can look like 'more milligrams' and still be the lock a QT history should keep shut.
Do not stack two PDE5 inhibitors to 'get more value.' The labels already warn against combining them. Do not split a 20 mg tablet at home to invent a 10 mg start unless a pharmacist has confirmed that tablet is scored and your prescriber asked for that cut. Cost-cutting that ignores the label is how people end up with either no effect or too much hypotension.
If you want a number you can take to a counter, ask that counter, or use a live discount listing dated today. Write [email protected] if a line on this note is stale. Do not write asking us to fill a bottle. This shelf does not sell.
04 Section
Dinner is the splitter the short tablets share
| Lock | Label food line | What a high-fat meal does |
|---|---|---|
| Tadalafil 10 mg PRN | May be taken without regard to food | No meal adjustment on the Cialis label |
| Sildenafil 25 mg | May be taken with or without food | Mean Tmax delay 60 min; mean Cmax down 29% |
| Vardenafil 20 mg | May be taken with or without food | High-fat meals cut Cmax by 18%-50% |
Cialis may be taken without regard to food. High-fat meals do not get a dose-adjustment clause on that label. If the evening plate is late, heavy, or both, the 10 mg weekend lock is the one whose food line stays quiet. That is a practical cost fact: a tablet that still peaks after dinner is worth more than a cheaper bottle that keeps missing the evening.
Sildenafil may be taken with or without food, which people misread as 'food does not matter.' A high-fat meal delays the mean peak by about 60 minutes and cuts mean Cmax by 29%. The 25 mg first tablet is already the cautious end of the Viagra ladder. Pairing it with a steak and a late clock is how a first try gets written off as 'the cheap one failed.' The swallow-after-dinner detail lives in the sildenafil timing guide.
Vardenafil may also be taken with or without food. Two food-effect studies on the Levitra label showed high-fat meals cutting Cmax by 18% to 50%. That range is wide enough that a 20 mg ceiling swallow after a heavy plate can behave like a smaller, later dose. The 20 mg lock on this shelf does not cancel the meal. It only names the highest labelled tablet.
Alcohol is not a fourth lock, but it is a third variable. Heavy drinking can blunt an erection on its own and can drop blood pressure when stacked with any PDE5 inhibitor. A light drink with a light plate is a different evening from a long dinner that also soaked the tablet.
05 Section
Onset and the useful window, side by side
Pick the clock your week can actually keep, not the name you heard in an ad. The table below is the labelled timing for the three strengths this note holds. It is not a ranking.
| Lock on this shelf | Usual swallow timing | Peak (fasted) | Useful window |
|---|---|---|---|
| Cialis 10 mg as needed (tadalafil) | Before the occasion; peak lands later than the short pair | 30 min to 6 h (median 2 h) | Up to 36 h after the dose |
| Viagra 25 mg (sildenafil) | About 1 h before; label range 30 min to 4 h | 30-120 min (median 60 min) | Hours, not a weekend; half-life about 4 h |
| Levitra 20 mg (vardenafil) | About 60 min before on the Levitra label | 30 min to 2 h (median 60 min) | Half-life about 4-5 h |
Tadalafil's half-life in healthy adults is about 17.5 hours. That is why a single as-needed swallow can still support erections up to 36 hours later if arousal is there. The peak is slower to arrive than the short pair: anywhere from half an hour to six hours, median two hours, on an empty stomach. People who want a Friday tablet to still matter on Saturday are shopping that window, not a magic name.
Sildenafil on an empty stomach reaches its peak between 30 and 120 minutes, median 60. The terminal half-life is about four hours. The Viagra label lets you take it from 30 minutes to four hours before sex. That is an evening, not a weekend. The 25 mg tablet on this shelf is still that short clock. Raising the milligrams later does not turn it into tadalafil.
Vardenafil after a 20 mg fasted dose usually peaks between 30 minutes and two hours, median 60, and clears with a half-life of about four to five hours. The Levitra label asks most people to swallow about 60 minutes before. Onset talk that claims a 15-minute race winner is marketing, not a reason to skip the nitrate check. The short pair look alike on a clock. They do not look alike on a QT line.
None of the three works without sexual stimulation. A tablet swallowed on a quiet afternoon does not produce an erection by the clock alone. Try the lock a prescriber actually opened more than once, with real arousal, the labelled swallow time, and a meal that matches that lock. One late night after a heavy dinner is not a verdict on the molecule.
06 Section
Side effects that split the three without ranking them
Splits, not a podium
- Shared ordinary effects: headache, flushing, stuffy nose, indigestion
- Sildenafil: visual tint more often discussed; still a short clock
- Tadalafil: next-day back or muscle ache more often discussed; long overlap
- Vardenafil: written QT avoid line; food still cuts the peak
- All three: stop for chest pain, sudden vision or hearing loss, or an erection past four hours
Headache, flushing, a blocked nose and dyspepsia show up across the class because the same enzyme lives in more than one vascular bed. Those are the ordinary complaints. They are not a reason to crown a gentler brand in a stranger. People differ. A man who flushed on sildenafil 25 mg may do fine on tadalafil 10 mg, or the reverse.
Sildenafil is the one most often tied to a blue or hazy visual tint. That tracks with some activity at PDE6 in the retina. It is usually transient. Sudden vision loss, or hearing loss, is a stop-and-call event on every PDE5 label, not a 'wait and see' quirk of one brand. Priapism lasting more than four hours is the same emergency on all three.
Tadalafil is the one most often tied to back pain or myalgia, often the next day, often blamed on the mattress. That tracks with some activity at PDE11. It is usually self-limited. It is also a longer overlap with anything you must not mix, because the drug is still there on Sunday morning.
Vardenafil's extra printed caution is the QT line above, not a unique headache rate that proves it is 'stronger.' Milligram figures do not travel from one INN to another. Ten milligrams of vardenafil was chosen in its own dose-finding work. Fifty milligrams of sildenafil was chosen in another. Twenty-five milligrams of sildenafil is a labelled step, not half a victory.
08 Section
The three short guides that sit under this note
A comparison that tried to reprint three monographs would be a clone. This note stops at the splits. The deeper single-drug pages and the three ED guides keep the rest.
Open the matching guide
The tadalafil guide settles one fork: a small daily tablet versus the 10 mg weekend swallow this comparison holds. If prostate symptoms are in the same visit, that guide is where the dual daily 5 mg claim lives. This page will not smuggle a daily winner into a PRN table.
The sildenafil guide is about the plate and the clock. A 25 mg first tablet fails in real life more often from a late fatty meal than from a 'weak' milligram. If you only read one linked page after this one, and your evenings are dinners, read that.
The vardenafil guide is about what a 20 mg ceiling changes, and what it does not. It does not outrun the QT avoid list. It does not outrun the nitrate ban. It does not make milligrams comparable across brands.
The full medicine notes stay under tadalafil, sildenafil and vardenafil. Use this comparison to pick a clock and a caution. Use those pages for dose cuts, hepatic and renal limits, and the rest of each ladder. Ingrid Sørensen's profile is the named peer-pass on every shelved note.
09 Section
What this comparison will not decide for you
If you need a long window and food never cooperates, the 10 mg tadalafil lock is the one that matches those two facts. If you want a short evening, can keep the plate light, and a cautious first tablet is the point, the 25 mg sildenafil lock matches those facts. If both short tablets are in play and the ECG or the antiarrhythmic list is dirty, the 20 mg vardenafil lock is the one to leave shut.
Those are matches, not medals. I still have not met you. Bring the nitrate list, the rhythm list, and how often you actually have sex. That is the visit. A prescriber who can see you still has to open one lock or none. Corrections and stale-line notes can reach [email protected]. Prescriptions cannot leave this shelf.