Sildenafil Citrate, the active ingredient in Ericta 100 mg, works by inhibiting the enzyme PDE5, which regulates blood flow in the penis. By inhibiting PDE5, Sildenafil Citrate promotes the relaxation of smooth muscles and increases blood flow to the peni... moreSildenafil Citrate, the active ingredient in Ericta 100 mg, works by inhibiting the enzyme PDE5, which regulates blood flow in the penis. By inhibiting PDE5, Sildenafil Citrate promotes the relaxation of smooth muscles and increases blood flow to the penis during sexual stimulation, leading to an erection. less