The active ingredient of Filagra (https://www.medypharmacy.com/product/filagra/), a drug used to treat erectile dysfunction (ED) in men, is sildenafil citrate, which is also included in Viagra. It works by suppressing the enzyme phosphodiesterase type 5 (PDE5), which improves blood flow to the penis during sexual stimulation, helping to create and keep an erection. Depending on the demands of each individual, Filagra comes in a variety of forms and strengths, such as oral jelly and tablets.