Sildenafil (Cenforce / generic Viagra) lasts 4–6 hours. Tadalafil (Vidalista / generic Cialis) lasts up to 36 hours. Both are FDA-approved PDE5 inhibitors — but they suit completely different lifestyles. This complete 2026 USA comparison covers onset, duration, food interactions, daily dosing, BPH treatment, visual side effects, the lifestyle match guide, full drug interaction warnings, and how to buy Cenforce and Vidalista with 50% off and free USA shipping at TheMedicineKar