One of the most common questions men have about ED medication is "when should I take it?" Each PDE5 inhibitor has a slightly different onset time, peak effectiveness window, and total duration. Understanding these differences helps you plan and reduces performance anxiety.
Sildenafil (Viagra)
- Take it: 30–60 minutes before sexual activity
- Peak effect: around 60 minutes
- Duration: 4–6 hours
- Food impact: high-fat meals can delay onset by up to an hour
Tadalafil (Cialis) — As Needed
- Take it: at least 30 minutes before, though some men take it 1–2 hours ahead
- Peak effect: around 2 hours
- Duration: up to 36 hours
- Food impact: minimal — can be taken with or without food
Tadalafil (Cialis) — Daily
- Take it: once daily at the same time, regardless of sexual plans
- Steady state: reached after approximately 5 days of continuous dosing
- Duration: continuous — you are always covered
Vardenafil (Levitra)
- Take it: 25–60 minutes before sexual activity
- Peak effect: around 60 minutes
- Duration: 4–6 hours
- Food impact: moderate — very fatty meals can reduce absorption
Avanafil (Spedra)
- Take it: approximately 15–30 minutes before sexual activity
- Peak effect: around 30–45 minutes
- Duration: approximately 6 hours
- Food impact: minimal impact from normal meals
Avanafil has the fastest onset of any licensed PDE5 inhibitor in the UK, making it a good choice for men who want maximum spontaneity with a short-acting medication.
Factors That Affect How Quickly They Work
Several factors influence onset time beyond the medication itself:
- Food — as noted above, fatty meals delay sildenafil and vardenafil
- Alcohol — excessive alcohol can delay absorption and impair erectile function independently
- Anxiety — performance anxiety can interfere with arousal, which is necessary for PDE5 inhibitors to work
- Underlying health — conditions such as diabetes or nerve damage may reduce responsiveness
A Practical Tip
If a medication does not seem to work the first time, the NHS advises trying it on at least eight separate occasions before concluding it is ineffective. Many men find it works better as they become more comfortable with the process.