Sildenafil, tadalafil, vardenafil and avanafil compared
Compare the four oral ED ingredients by brand, prescribing context and label-specific differences.
The four oral ingredients belong to the PDE5 inhibitor family. Each needs sexual stimulation, and a clinician chooses among them using medical history, interactions, response and the relevant label. A brand comparison cannot establish which will work best for an individual.
Compare the documented differences
| Ingredient | Product examples in this directory | Distinction to discuss |
|---|---|---|
| Sildenafil | Viagra, Penegra | Use before sexual activity; food can delay onset in the Viagra label |
| Tadalafil | Cialis, Tadacip | Separate daily and as-needed regimens in the cited labels |
| Vardenafil | Levitra | Film-coated and orodispersible formulations; specific QT-interval precautions |
| Avanafil | Spedra, Stendra | Strength-dependent timing and restrictions with strong CYP3A4 inhibitors |
What a comparison cannot tell you
A stated onset is not a guaranteed result. A treatment window is not an erection lasting for that period. Milligram strengths across different ingredients are not equivalent doses.
Bring your current prescription, medicine list and any problems with response to the prescriber. Do not combine products to compare them yourself. When treatment does not work offers a discussion checklist.
Check safety first
Nitrates are incompatible with these medicines. Review interactions and urgent symptoms before focusing on convenience or brand names. Product profiles link to the exact jurisdiction and formulation used for this comparison.
Sources
Sources checked 2 October 2026.