Short description Tadacip (Tadalafil) is an oral drug, used for treating male impotence also known as men&rsquos erectile dysfunction. Tadacip&rsquos effect starts working in 30 minutes and lasts for about 48 hours, while Viagra effect lasts for about 4 hours. Tadacip is to be taken with or without food. Tadacip is to be used for daily use, so you can be ready anytime.