Meds arrive in the mail in just two days. The generic versions are just as effective and much less expensive. It’s best to check your chosen provider’s site for more information. Generic vs. It works thanks to its active ingredient, Sildenafil citrate. These are commonly prescribed for an enlarged prostate or male pattern baldness. The most common symptoms of erectile dysfunction include difficulty achieving or maintaining an erection and reduced sexual desire.tadalafil (Cialis) vardenafil (Levitra) avanafil (Stendra) About 30 million men in the United States occasionally have a problem with getting or keeping an erection, according to the Urology. Cialis. Rather than Viagra’s 50 or mg blue pills, Cialis comes in lower doses, the smallest of which is just mg. That allows for daily use, ensuring the drug’s always in your system. Viagra and Cialis are the most popular ED (erectile dysfunction) drugs in the world, but they’re not the only ones. They’re equally safe and effective, but they differ a bit in how fast they work, how long they last, and how much they cost. Here’s what you need to .