About Tadalafil Improved erectile function Extended duration of action for up to 36 hours Enhanced sexual performance and satisfaction How it Works Tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor, works by enhancing the effects of nitric oxide, a chemical that relaxes smooth muscles in the blood vessels. This relaxation increases blood flow to specific areas of the body, primarily assisting in the treatment of erectile dysfunction.