ED pills not working? Reasons and what a clinician checks
Three things the sildenafil and tadalafil labels print can change how a pill seems to work: sexual stimulation, food, and timing. Taking more is not the fix, and a clinician decides any change.
If ED pills are not working: three things the labels print
Before asking whether a pill failed, check how it was taken. The sentences below are copied from the sildenafil and tadalafil prescribing information, opened 2026-10-16. They are not dosing advice, and nothing here says to take more.
| Question | Sildenafil label | Tadalafil label |
|---|---|---|
| Is sexual stimulation needed? | “Sildenafil at recommended doses has no effect in the absence of sexual stimulation.” | “Because sexual stimulation is required to initiate the local release of nitric oxide,” the inhibition of PDE5 by tadalafil “has no effect in the absence of sexual stimulation.” |
| Does food matter? | “When VIAGRA is taken with a high fat meal, the rate of absorption is reduced, with a mean delay in Tmax of 60 minutes.” The label also says it may be taken with or without food. | “CIALIS may be taken without regard to food.” |
| When is it taken? | “Approximately 1 hour before sexual activity.” The label also says it may be taken anywhere from 30 minutes to 4 hours before sexual activity. | As needed, “taken prior to anticipated sexual activity.” Once-daily dosing is taken at about the same time each day, regardless of when sexual activity is planned. |
Stimulation
Both labels say the medicine has no effect without sexual stimulation. If a pill was taken and nothing happened, say whether there was arousal. A clinician will want to know.
Food
The sildenafil label says a high-fat meal slows absorption, with a mean delay in Tmax of 60 minutes. The tadalafil label says it may be taken without regard to food. A meal is a detail to report, not a reason to change the dose.
Timing
The sildenafil label gives a window of 30 minutes to 4 hours before sexual activity, with about 1 hour as the usual timing. The tadalafil label has an as-needed schedule and a once-daily schedule, and the two are not interchangeable. See sildenafil, tadalafil, and daily tadalafil for what each label prints.
What a clinician checks
A clinician looks at which medicine you took, how it was taken (timing, food, arousal), and your health history and other medicines. They decide whether to stay with the current plan, change the medicine or schedule, or stop. A change in dose is the clinician’s call, not something to do on your own. Do not combine ED medicines unless a clinician prescribed that combination.
Some people ask about other options. The apomorphine guide covers what its label is and is not. Mendoxa does not promise a result, and a prescription is not automatic.
Get emergency care for an erection lasting more than 4 hours or a sudden loss of vision or hearing, as the sildenafil guide describes.
References
Opened 2026-10-16.
- DailyMed: Viagra (sildenafil citrate) tablets. Stimulation (12.1), food (12.3, 2.2), timing (2.1).
- DailyMed: Cialis (tadalafil) tablets. Stimulation (12.1), food (2.5), timing (2.1, 2.2).
About Mendoxa
- Mendoxa serves 49 U.S. states. Not available in California.
- Licensed clinicians in the LocumTele network review every intake. The clinician can say no.
- When a prescription is issued, Rush Pharmacy fulfills it.
- A compounded medicine is not an FDA-approved finished product.
- The price is shown in the intake, not on this page.
Compounded medication prescribed only if a licensed U.S. clinician decides it is appropriate. Not FDA-approved as a finished product. Not available in California.