Tadalafil is the active ingredient of the drug Tadarise 20 mg. A typical treatment for erectile dysfunction in adult males is the phosphodiesterase type 5 inhibitor tadalafil. Before beginning to use tadalafil and each time you receive a refill, read the Patient Information Leaflet, if it is available from your pharmacist. See your physician or pharmacist if you have any queries. Take this drug orally, as prescribed by your physician, either with or without food. Tadalafil should not be taken more than once per day. The patient consumed a high-fat lunch, which may have delayed the medication's effects. Tadarise 20 mg helps you achieve the best possible erection throughout the hour of sexual activity by drawing blood to the penis.