It is within the PDE5 inhibitor class (which also includes avanafil, sildenafil, tadalafil, and vardenafil).

[1] It has fairly rapid onset of action (peak plasma concentration after 1 to 1.5 hours), and has long duration of action (plasma half-life of 11 to 13 hours).

Udenafil's pharmacokinetics allows once-daily dosage (in addition to on-demand use).

[2] Typical doses are 100 and 200 mg. Udenafil is available in Korea, Russia, and the Philippines.

[3] It has not yet been approved for use in the United States by the U.S. Food and Drug Administration.