First, the four things that are usually wrong
Before concluding the drug does not work for you, rule these out. In clinic they account for most of the men who arrive saying it failed.
1. The dose was never increased
Sildenafil is commonly started at 50 mg. The maximum is 100 mg, and a meaningful share of men who get nothing at 50 respond at 100. Tadalafil on demand runs from 10 mg to 20 mg on the same logic.
Many men never get past that first prescription — they try the starting dose, it does not work, and nobody escalates it because nobody is asked. If you have not tried the top of the range, you have not tried the drug.
2. Not enough attempts
The standard advice is at least eight separate occasions at an adequate dose before calling it a failure, and there is a reason for that number. Response often improves across the first several attempts as the anxiety around whether it will work subsides. Men who try twice and stop are frequently measuring their nerves rather than the medication.
3. Food, alcohol and timing
Sildenafil is meaningfully affected by a heavy or fatty meal, which delays and blunts absorption. Take it on a relatively empty stomach and allow 30 to 60 minutes. Tadalafil is far less fussy about food and has a much longer window, which is one of the main practical reasons to prefer it.
Alcohol works against you twice: it is a depressant that reduces the arousal signal, and in quantity it lowers blood pressure alongside a drug already doing the same thing. A glass is fine. An evening of it is a fair explanation for a failed attempt. Sildenafil and tadalafil compared.
4. Expecting it to generate desire
This is the most common misunderstanding of all. PDE5 inhibitors block the enzyme that breaks down the erection signal — they make an existing signal last and build. They do not produce the signal.
With no arousal, a maximum dose does essentially nothing, and that is the drug working exactly as designed. Men who take one and wait for something to happen unassisted conclude, reasonably but wrongly, that it failed.
Then: switch the molecule
Failing one PDE5 inhibitor is a poor predictor of failing the others. They differ in how selectively they act and how long they last, and men do respond differently to each for reasons that are not always clear.
If sildenafil has had a fair trial and done nothing, tadalafil is the obvious next step — and vice versa. It is a cheap experiment with a reasonable chance of working, and it should happen before anyone starts describing you as a non-responder.
Consider daily dosing instead
Low-dose tadalafil taken every day is a different approach rather than a smaller version of the same one. Instead of a dose timed to an occasion, it maintains a low continuous level so that sex does not require planning.
For some men this simply works better, and the reason is often as much psychological as pharmacological: removing the countdown removes a large part of the pressure. It also happens to treat benign prostatic hyperplasia, which is common in the same age group. More on the oral options.
Things that block a drug that would otherwise work
If a fair trial of two different molecules has failed, the question shifts from the drug to what is working against it.
- Low testosterone reduces how well PDE5 inhibitors work. Correcting a genuine deficiency can restore the response in men for whom pills previously did nothing. It needs two morning blood tests, not a questionnaire. What testosterone therapy does.
- Other medications may be pulling in the opposite direction — older beta blockers, thiazide diuretics, SSRIs and finasteride among them. Worth a formal review rather than a guess. The full list.
- Uncontrolled diabetes blunts the response substantially, because these drugs need a nitric oxide signal that damaged nerves and vessels struggle to produce. Why diabetes changes the approach.
- Untreated sleep apnea contributes through low overnight oxygen and suppressed testosterone, and is very commonly missed in this age group. The sleep apnea link.
- Severe vascular disease may simply have progressed beyond what an amplifier can rescue, which is a genuine finding rather than a failure.
If it worked before and has stopped
A drug that used to work and no longer does is a different situation from one that never worked, and it deserves an appointment rather than a dose increase.
Tolerance to PDE5 inhibitors is not really a recognised phenomenon — these drugs do not usually wear out. What has more often happened is that something underneath has progressed: worsening vascular disease, a new medication, weight gain, rising blood sugar, or a new anxiety loop layered on top.
The loss of response is a signal about your health, not just your prescription. It is worth investigating as such. Why ED tracks cardiovascular risk.
What comes next, and how well it works
This is the part men are rarely told, and the reason many stop at a failed pill and assume that was the ladder: it is roughly the first rung of four.
| Option | How it works | Realistic expectation |
|---|---|---|
| Injections | Opens the arteries directly, with no nerve signal required | Works for the large majority, including most men who fail pills. The needle is smaller than men imagine and the first dose is given in clinic. |
| Vacuum device | Draws blood in mechanically, held by a ring | Works almost regardless of the underlying cause. Reliable and cheap; most complaints are about spontaneity rather than effectiveness. |
| Urethral suppository | Same drug as injections, absorbed through the urethra | Less effective than injecting, but needle-free. A reasonable middle step. |
| Implant | Surgically placed inflatable device | The highest satisfaction rate of any ED treatment, and irreversible — it replaces the natural mechanism rather than assisting it. |
The step most often skipped is the second one. Injections have a strikingly high success rate and men consistently rule them out before asking anything about them. What injections actually involve.