Article
How long does sildenafil last?
Sildenafil typically lasts about 4 to 6 hours, with onset in 30 to 60 minutes; food and alcohol affect it.
Sildenafil (Viagra) typically lasts about 4 to 6 hours, with its strongest effect in the first hour or two after it takes effect. It begins working in roughly 30 to 60 minutes. The exact duration varies with dose, food, age and individual factors. This article explains the timeline and what affects it.
It is a topic in our erectile dysfunction and men's sexual health section.
The usual timeline
After swallowing sildenafil, it is absorbed over about 30 to 60 minutes, reaches a peak, and then its level gradually falls. The useful window for most men is around 4 to 6 hours, though it does not provide a constant erection — arousal is still needed throughout.
What can shorten or delay it
A heavy, fatty meal slows absorption, delaying onset and sometimes making it feel weaker. Alcohol works against erections. Higher doses may last a little longer, and metabolism varies with age and health, so the window differs from person to person.
| Phase | Approximate timing |
|---|---|
| Onset | 30–60 minutes |
| Peak effect | first 1–2 hours |
| Total window | about 4–6 hours |
Sildenafil versus tadalafil
Sildenafil is relatively short-acting. Tadalafil (Cialis) lasts far longer — up to about 36 hours — which is why it is sometimes chosen for more spontaneity. The choice depends on lifestyle and is best made with a doctor. See tadalafil for ED.
Getting the timing right
For a reliable effect, take sildenafil around an hour before sex, ideally apart from a heavy meal and without excess alcohol. Planning the timing prevents the common impression that it "did not work" when it was simply taken too late or after a big dinner.
It is not continuous
An important point: lasting "4 to 6 hours" does not mean a constant erection for that time. It means the drug is active and can support erections when arousal occurs during that window. To speed onset, see how to speed up Viagra.
Speed it up: how to speed up Viagra. Tadalafil: tadalafil for ED. Mechanism: sildenafil's mechanism.
Planning around the window
Knowing the roughly 4-to-6-hour window helps with planning: take sildenafil about an hour before sex, and remember that the window is when it can work, not a guarantee of continuous effect. If you regularly need a longer or more flexible window, that is worth raising with a doctor, who may suggest the much longer-acting tadalafil instead. Matching the drug to your pattern of use makes it far more satisfactory.
A note on consistency
One more practical point: sildenafil's window can feel slightly different from day to day, depending on food, alcohol, stress and arousal. This is normal and does not mean the medicine has stopped working. Taking it under similar, favourable conditions — light stomach, relaxed setting, genuine arousal — makes both its onset and its duration more predictable, so you get a consistent experience within that 4-to-6-hour window.
Frequently asked questions
- How long does sildenafil last?
- About 4 to 6 hours, with the strongest effect in the first hour or two; onset is 30–60 minutes.
- Does it give a constant erection?
- No; it is active for that window but still needs arousal each time.
- What makes it last longer?
- Tadalafil, a different drug, lasts much longer; sildenafil's window varies with dose and metabolism.