Tadalafil rely on the PDE - 5 to improve NO decomposition of the inhibition of cGMP vasodilation effect, made the ED patient regain penile erectile ability, taking him up to that after not absorbed by the intestines and stomach. Tadalafil that the average working time is 16-30 minutes, taking the peak plasma concentration of 2-8 hours after, the half-life of 44-112 hours, the kidney function not full-time longer half-life, even five days later, he still can be measured in plasma of the non concentration.Clinical report after taking cialis efficiency reached 83%, report for 10 to 20 mg dose.Its advantage is side effect little, long duration and is available in two or three days or so has the obvious effect.