The use of Viagra sildenafil after the general how long can take effect?

After taking Viagra Sildenafil, the effect is about 0.5 to 2 hours, and the fastest effect is 14 minutes

Randomized, double-blind, placebo-controlled study: 228 patients with ED who received sildenafil (100mg) and responded well to treatment were enrolled. Randomized to sildenafil 100mg (n=115) or placebo (n=113) for 4 weeks prior to sexual activity, the time to achieve an erection sufficient for successful insertion was assessed.

The plasma peak concentration was reached 30 to 120 minutes after oral administration of the drug in the fasting state, and the absorption rate was reduced when the drug was taken with a high-fat diet. The peak time was delayed by an average of 60 minutes, and the plasma peak concentration was decreased by an average of 29%, but the degree of absorption was not affected. The elimination half-life of sildenafil and its metabolites is about 4 hours.