Levitra contains vardenafil, which acts as a selective phosphodiesterase type 5 (PDE5) inhibitor. In simple terms, this means vardenafil targets an enzyme (PDE5) found mostly in the blood vessels of the penis. By blocking PDE5, Levitra increases the amount of a molecule called cyclic guanosine monophosphate (cGMP), which relaxes smooth muscle cells and allows blood to flow more easily into the penis during sexual stimulation (PubMed, 2024).
Metaphor: Imagine blood vessels as garden hoses. PDE5 “clamps” the hose, reducing flow. Levitra releases the clamp temporarily, so more water (blood) can flow when the tap (sexual arousal) is turned on.
- Levitra will not cause an erection on its own. Sexual stimulation is required.
- The effect is temporary: cGMP is only increased for a few hours after taking the medicine.
- Other body systems (vision, hearing, blood pressure) can be affected—see side effects for details.
Myth vs Reality: Myth: “Levitra works instantly, no matter what.” Reality: Most people need at least 25–60 minutes, and sexual stimulation, for the medicine to work effectively.
Evidence: Randomised, placebo-controlled studies have shown that vardenafil improves erectile function in 70–84% of men with erectile dysfunction (NICE, 2024).