For some, one can be more effective than the other. It might work longer if you have mild to moderate erectile dysfunction. Your partner might see your inability to have an erection as a sign of diminished sexual interest. This medication is taken with or without food an hour before sex. Include physical activity in your daily routine. Key Takeaways… So, Cialis vs Viagra — who won? · Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way. Dosing. Your doctor may adjust your dose as . Cost Overdose Ask your doctor Q&A Drug Images What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a . Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes .