| Best for |
Planned sex: Take it before you expect to have sex. A well-studied, affordable option. |
If sildenafil doesn’t suit you: A good alternative for men who don’t respond well to sildenafil or experience unwanted effects. |
Flexible & spontaneous: Works for much longer, so you don’t have to plan sex around a short window. |
| How fast it works |
~30–60 min |
~25–60 min (may feel slightly faster) |
~30–60 min (peaks slower, ~2 hr) |
| How long it lasts |
4–6 hours
|
4–6 hours
|
Up to 36 hours
|
| Take before sex |
About 1 hour before |
About 25–60 min before |
30 min–2 hr before (flexible) |
| Effect of food |
A high-fat meal delays it and lowers the peak (~29%) — best on an empty stomach. |
Less affected
— a moderate meal has no real effect; only a very high-fat meal slightly delays it.
|
Minimal — take with or without food. |
| Potency & typical dose |
Standard selectivity; 25–100 mg (start 50 mg). |
More potent & selective for PDE5
— works at lower milligrams; 5–20 mg (start 10 mg).
|
Highly selective; 10–30 mg as needed (2.5–5 mg daily). |
| Visual side effects |
Temporary colour-vision changes or light sensitivity are possible. |
Less likely
— being more selective, it rarely affects colour vision.
|
Uncommon. |
| Well studied in |
The broadest evidence base, across many groups. |
Men with
diabetes
, and men who didn’t respond to sildenafil.
|
Daily, always-ready dosing for steady preparedness. |
| Dosing options |
As needed |
As needed |
As needed
or
daily
|
| Reviews |
★★★★★
4.8
· 200+ reviews
|
★★★★★
4.7
· 100+ reviews
|
★★★★★
4.9
· 200+ reviews
|
| Orders |
1,500+
ordered
|
1,100+
ordered
|
1,600+
ordered
|
| References |
NHS, Mayo & more →
|
Patient.info, DailyMed & more →
|
NHS, Mayo & more →
|