Valif 20 mg is a brand of vardenafil, a PDE5 inhibitor used to treat erectile dysfunction (ED). It works by increasing blood flow to the penis during sexual stimulation, helping men achieve and maintain an erection. It does not increase sexual desire and requires sexual stimulation to work. The usual recommended starting dose of vardenafil is often 10 mg, while 20 mg is generally the maximum recommended dose. It should be taken only as directed by a healthcare professional and should not be taken more than once a day. A high-fat meal may delay its effect.