Viagra and sildenafil are effective treatment options for ED, but they both require a prescription. As a result, you cannot buy them over the counter (OTC) — they require a consultation with a ...

The main difference between Cialis and Viagra is how long each lasts. Cialis stays in your system for up to 36 hours, and you ...

But other nuances about how — and when — these medications should be taken will ultimately be very important when deciding which one is right for you. Is Cialis stronger than Viagra?