Description: Tadalafil 20mg tablets has been shown to significantly improve the ability of obtaining a hard erect penis suitable for sexual activity. Tadalafil contains the active substance tadalafil. Following sexual stimulation Tadalafil works by helping the blood vessels in your penis to relax, allowing the flow of blood into your penis. The result of this is improved erectile function. Tadalafil does not work if there is no sexual stimulation.