Brand Viagra - a drug from Pfizer, with a basic chemical called Sildenafil Citrate, is a first developed pharmaceutical to cure the difficulties with erection. It functions approximately within 4-5 hours, must be taken an hour prior to sex.

Cialis Professional - effective tablets for improvement of erection. They begin to work in 15 minutes from the moment of taking and actions for 36 hours. They can cause not less than 10, but no more than 16 erections. The medicine increases duration of sexual intercourse. The tablets are successfully used for reduction of time for recovery of erection after ejaculation.

Cialis is a latest medicine for treatment of disturbances of erection at men. Sialis's feature is its high-speed performance (30 minutes) and a long-term effect (up to 36 hours). In this regard you can choose the moment which is most suitable for sexual intercourse, having accepted a drug in advance. It is possible to take Sialis in the morning and to be ready even next day. Active ingredient - Tadalafil, the recommended dosage - 20 mg.