- First: it almost certainly isn’t a faulty tablet
- Reasons 1–3: the clock, the dinner, the drinks
- Reasons 4–5: nothing to amplify, and first-night nerves
- Reasons 6–7: 50 vs 100 mg, and what “working” looks like
- Reason 8: something underneath that needs a doctor
- Reason 9: sildenafil isn’t your drug — try tadalafil
- When to stop self-treating
- Questions we get asked
“Took one last night. Nothing.” That email, or a version of it, lands most mornings. The customer is annoyed, sometimes embarrassed, and almost always sure the tablet was the problem. It rarely is. After years of reading these and writing back, the same nine causes come up nearly every time — and seven of them can be fixed before your next attempt without buying anything new.
This isn’t a lecture. Sildenafil has real limits, and reasons 8 and 9 are about recognising when it’s the wrong tool. But go through the first seven honestly first.
First: it almost certainly isn’t a faulty tablet
We ship sealed manufacturer blisters with the batch printed into the foil, and a batch that failed would fail for hundreds of people at once. That doesn’t happen. What does happen: a man takes his first tablet after a big dinner and three glasses of wine, twenty minutes before he needs it, with a partner he’s anxious about disappointing. Then he blames the chemistry.
Clinical trials say many men don’t respond to the first dose but do by the third or fourth. Our inbox agrees. Don’t judge sildenafil on one night.
Reasons 1–3: the clock, the dinner, the drinks
1. You took it too late
The leaflet says 30–60 minutes. Thirty is the optimistic end. Sildenafil peaks at about one hour, and for many men the useful effect doesn’t arrive until then. Take it at 9:40 for a 10:00 start and you’re performing while the drug is still being absorbed. Fix: a full hour ahead, the first few times. If a fixed hour of lead time doesn’t suit your evenings, that’s a real argument for tadalafil — see reason 9.
2. You took it after a heavy meal
The big one. A fatty dinner — steak, pizza, curry, a cheese board — slows sildenafil’s absorption dramatically. The peak arrives later and lower. A tablet taken after a heavy meal may do little for two hours, then less than it should. The Cenforce 100 guide goes deeper, but the short version is empty stomach or a light meal, water only. Grapefruit juice is the opposite problem — it raises sildenafil levels and side effects. Skip it on the day.
3. You’d had more than two drinks
Alcohol is a sedative and a vasodilator. In quantity it causes erectile difficulty on its own, drops your blood pressure, and blunts sensation. Sildenafil cannot out-argue a bottle of wine. One or two drinks is fine. Beyond that, whatever happens isn’t a fair test. On your test nights, keep it to one.
Reasons 4–5: nothing to amplify, and first-night nerves
4. There wasn’t enough arousal
Sildenafil does not cause an erection. It stops your body cancelling one. The signal still has to come from you — from touch, from your partner, from wanting it. Take the tablet, sit through a film, and wait for something to happen on its own? Nothing will. That is the number-one “faulty tablet” email we get, and the tablet is fine.
Which also means sildenafil does nothing for low desire. If the problem is that you don’t feel like it, a PDE5 inhibitor is the wrong shelf — that’s a doctor’s conversation about testosterone, mood or medication.
5. First-attempt nerves
Anxiety releases adrenaline. Adrenaline constricts blood vessels. Sildenafil relaxes them. On a night where you’re watching yourself, waiting for the pill to “kick in”, worried about what happens if it doesn’t — adrenaline wins. That’s why so many second attempts work when the first didn’t: the pressure is off. Take the first dose on a low-stakes evening. Some men take it alone, just to see what their body does. It removes the audience.
Reasons 6–7: 50 vs 100 mg, and what “working” looks like
6. The dose was too low for you
50 mg is the official starting dose and the right place to start. It’s also, by our order book, the dose most often stepped up. If you’ve had two or three properly controlled attempts at 50 mg — full hour, light stomach, one drink, real arousal — and got a partial result without side effects, 100 mg is the next step, and it’s the licensed maximum. Not 150. Not 200. Cenforce 150 and 200 exist and we sell them, but they sit above the licensed dose and mostly add headache and flushing, not effect. Only under medical advice.
Practical note: Cenforce 100 is scored, so buying the 100 and halving it gives you both doses from one pack.
Cenforce 100 mg
- Composition
- Sildenafil Citrate (100mg)
- Manufacturer
- Centurion Laboratories
- Equivalent to
- Viagra
- Packaging
- 10 tablets in 1 strip
- Sealed manufacturer packs
- Free tracked delivery on every order
- Plain packaging
| Pack | Price | Per tablet | |
|---|---|---|---|
| 30 Tablets | $59.00 | $1.97 | Select › |
| 60 Tablets | $89.00 | $1.48 | Select › |
| 90 Tablets | $119.00 | $1.32 | Select › |
| 100 Tablets | $98.00 | $0.98 | Select › |
| 120 Tablets | $139.00 | $1.16 | Select › |
| 150 Tablets | $144.00 | $0.96 | Select › |
| 180 Tablets | $179.00 | $0.99 | Select › |
| 200 Tablets | $160.00 | $0.80 | Select › |
| 300 Tablets | $225.00 | $0.75 Best value | Select › |
| 360 Tablets | $269.00 | $0.75 Best value | Select › |
7. Your expectations were wrong
Some men expect an erection that appears by itself and stays for four hours regardless. That’s not sildenafil; that’s a medical emergency (any erection over four hours needs a hospital). What sildenafil does is make a normal, stimulation-driven erection easier to get and keep. It goes down after orgasm like it always did. It can come back with more stimulation while the drug is active. The men happiest with it expected a firmer, more reliable version of what they already had. If the erection came but wasn’t as rigid as you wanted, that’s a partial response — exactly where moving from 50 to 100 mg is designed to help.
Reason 8: something underneath that needs a doctor
PDE5 inhibitors need working nerves and reasonable blood flow to amplify. Some conditions damage one or both, and in those men sildenafil at any dose won’t do much. This is where we stop being useful and a doctor starts:
- → Diabetes, especially long-standing — nerve and small-vessel damage
- → Untreated high blood pressure or cholesterol — the arteries that cause heart disease cause ED first
- → Low testosterone — sildenafil works far better when it’s in range
- → Prostate surgery or pelvic radiotherapy
- → Depression, anxiety, and the SSRIs used for them — a very common cause
- → Beta-blockers, some diuretics, antihistamines, finasteride
- → Heavy smoking, heavy drinking, sleep apnoea
If any of those describe you and sildenafil isn’t working, don’t keep buying higher strengths. Book the appointment. ED is frequently the earliest warning of cardiovascular disease.
Reason 9: sildenafil isn’t your drug — try tadalafil
Some men simply get on better with a different PDE5 inhibitor. A non-responder to one is sometimes a responder to another. Tadalafil (Vidalista, Tadalista, Tadacip) is the usual second try because it solves three of the nine reasons at once:
| Problem with sildenafil | What tadalafil does instead |
|---|---|
| Needs an hour of lead time (reason 1) | Works up to 36 hours — take it in the afternoon, forget the clock |
| Blunted by a fatty meal (reason 2) | Food has no meaningful effect |
| Pressure of a 4-hour window (reason 5) | The window is a day and a half; no “now or never” |
| Flushing or blue-tinted vision | Much less common; trade-off is back or muscle ache a day later in some men |
| Want a daily option | Tadalafil 5 mg daily is licensed (Vidalista 5) |
Start at 10 mg (half a Vidalista 20), maximum 20 mg on demand — the licensed ceiling; Vidalista 40, 60 and 80 sit above it. Leave 24 hours after sildenafil before switching. Never take both on the same day. We compared them properly in Vidalista 20 vs Cenforce 100; if you’ve arrived here from a failed sildenafil night, read that next.
Vidalista 20 mg
- Composition
- Tadalafil 20mg
- Manufacturer
- Centurion Laboratories
- Equivalent to
- Cialis
- Packaging
- 10 tablets in 1 strip
- Sealed manufacturer packs
- Free tracked delivery on every order
- Plain packaging
| Pack | Price | Per tablet | |
|---|---|---|---|
| 30 Tablets | $59.00 | $1.97 | Select › |
| 60 Tablets | $89.00 | $1.48 | Select › |
| 90 Tablets | $119.00 | $1.32 | Select › |
| 120 Tablets | $139.00 | $1.16 | Select › |
| 150 Tablets | $123.00 | $0.82 | Select › |
| 180 Tablets | $179.00 | $0.99 | Select › |
| 300 Tablets | $207.00 | $0.69 Best value | Select › |
| 360 Tablets | $269.00 | $0.75 | Select › |
Vardenafil (Vilitra 20) and avanafil (Avana 100) are the other two options — avanafil starts fastest, 15–30 minutes, and cares least about dinner.
When to stop self-treating
We sell these tablets. But there’s a point at which “try another pack” becomes bad advice, and we’d rather say so plainly. Stop and see a doctor if:
- You’ve had 4 or more controlled attempts at 100 mg (full hour, light stomach, one drink, real arousal, no nerves) with no response
- You’ve tried tadalafil 20 mg the same way and it hasn’t helped either
- You get chest pain, severe dizziness or fainting with any dose
- Your ED came on suddenly, or with pain, curvature or numbness
- You have diabetes, heart disease or take blood-pressure medicine and haven’t been checked in a year
- Any erection has lasted more than four hours — that’s an emergency, not an appointment
What a doctor can do that we can’t: measure testosterone, check blood sugar and lipids, review what you already take, and if PDE5 inhibitors genuinely don’t work for you, talk about injections, vacuum devices or implants. All of them work for men the tablets don’t.
Questions we get asked
Why did sildenafil work once and then stop?
Usually because the conditions changed, not the drug. A heavier meal, more alcohol, less lead time, or more pressure on the night are the common culprits. Sildenafil doesn’t stop working through tolerance. Go back to the conditions that worked — full hour, light stomach, one drink — and compare. If a controlled attempt still fails, see a doctor to rule out a new cause.
Should I take 100 mg if 50 mg didn’t work?
If two or three controlled attempts at 50 mg gave a partial result and no troublesome side effects, yes — 100 mg is the next step and the licensed maximum. If 50 mg produced nothing at all despite proper timing and arousal, moving up may help, but a complete non-response is also a reason to talk to a doctor about underlying causes rather than simply doubling.
Can I take a second tablet if the first didn’t work?
No. The maximum is 100 mg in 24 hours. A second tablet doesn’t rescue a failed attempt — the first is still in your system — it only stacks the side effects and the blood-pressure drop. Wait until the next day, fix the timing and food, and try again.
Is tadalafil stronger than sildenafil?
Not stronger — longer. Tadalafil 20 mg and sildenafil 100 mg are the maximum on-demand doses of two different drugs. Tadalafil lasts up to 36 hours and isn’t affected by food, which removes the timing and dinner problems that sink many sildenafil attempts. Some men respond to one and not the other, so switching is a reasonable next step.
How many times should I try before giving up?
Three or four properly controlled attempts at 100 mg: a full hour of lead time, an empty or light stomach, no more than one drink, genuine stimulation and a low-pressure evening. Many men who fail the first attempt respond by the third. If four controlled attempts do nothing, switch to tadalafil or see a doctor.
Does sildenafil work with low testosterone?
Often poorly. PDE5 inhibitors amplify a signal that testosterone helps generate, and men with low levels frequently get a weak response until that’s corrected. If you have low libido, fatigue and a poor response to sildenafil, ask a doctor for a testosterone blood test before buying more tablets.
What to do now
Pick a quiet evening this week. Take a Cenforce 100 — whole if 50 mg already gave a partial result, half if this is your first go — a full hour before, on an empty stomach, one drink at most, no audience if that helps. Do that three times before drawing conclusions. If it still isn’t working, our honest recommendation is to switch to Vidalista 20, which takes the clock and the dinner out of the equation — read the comparison first. And if you’ve done all that and nothing’s changed, book the doctor. That’s not a failure; it’s the next step. Stuck on which pack? Email us. A person answers, any hour.
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