The average onset time of tadanafil is 16-30 minutes, and the plasma concentration peaks 2-8 hours after administration, with a half-life of 44-112 hours. The half-life is prolonged with renal insufficiency, and the level of tadanafil can still be measured in the plasma even after 5 days. Its advantage is side effect is small, duration is long, can have obvious effect in two or three days or so.The recommended dose of tadanafil is 10mg, taken before sex and not affected by food intake. If 10mg is not effective, 20mg can be taken at least 30 minutes before sex, with a maximum of once a day. It is best not to take tadalafil daily. The best use on an empty stomach, before use do not drink, strong tea, spicy food (users in a state of sexual stimulation under the use of the effect is significant).Some users will have adverse reactions, generally dry mouth (sexual hunger and thirst), back muscle pain, muscle weakness, headache, facial flushing, heart rate acceleration, excessive will lead to frequent headache, excessive energy, not drowsiness.