Tadalafil, a drug used to treat erectile dysfunction (ED) in men, is marketed under the brand name Tadacip 20. It is a member of the group of medications known as phosphodiesterase type 5 (PDE5) inhibitors. Tadacip helps men get and keep an erection by boosting blood flow to the penis during sexual stimulation. It is given orally, usually between 30 and 60 minutes prior to planned sexual engagement. Before using Tadacip, like with any medicine, make sure you understand the dosage guidelines and speak with a doctor, particularly if you have any underlying medical conditions or are taking other medications.