Tadarise 20mg (generic Tadalafil ) are used to treat erectile dysfunction (impotence) in men. Tadarise tablets 20mg contain tadalafil, a phosphodiesterase type 5 inhibitor, that is used to treat erectile dysfunction in men. tadalafil in Tadarise tablets 20mg inhibit the breakdown (by the enzyme PDE5) of a chemical called cGMP. The most commonly reported side effects when taking Tadarise tablets 20mg include headache, dizziness or light-headedness, flushing, nasal congestion, dyspepsia (heartburn), nausea. Less common side effects include, visual disturbance, increased tear formation causing watery eyes, changes in blood pressure (hypo and hypertension), sleepiness, dyspnoea (shortness of breath), pain (in the back joints, abdomen). Several medications interact with Tadarise tablets 20mg and should either not be taken while you are taking Tadarise or only after discussion and instruction from your doctor. The effect of Tadarise tablets 5mg usually lasts as long as 4-5 hours after taking your tablet, but you can take your Tadarise tablet 20mg up to 36 hours.