Vilitra 10 mg contains vardenafil, a phosphodiesterase type 5 (PDE5) inhibitor used to treat erectile dysfunction (ED). It acts primarily in the penis, targeting the biochemical pathways involved in achieving and maintaining an erection. Here's how it works in the body: Site of Action: Corpus cavernosum of the penis (the spongy erectile tissue) This is where blood flow needs to increase for an erection to occur.Vilitra 10 mg  of Action: During sexual stimulation, nitric oxide (NO) is released in the penis. NO increases the production of cyclic guanosine monophosphate (cGMP), which relaxes smooth muscle and allows blood vessels to dilate. Vilitra (vardenafil) inhibits PDE5, the enzyme that breaks down cGMP. This inhibition results in higher cGMP levels, leading to enhanced blood flow to the penis and helping produce and maintain an erection. Important Note: Vilitra only works in the presence of sexual stimulation. It does not cause an automatic erection without arousal.