Use only the brand of this medicine that your doctor prescribed. Viagra can be taken as long as four hours or as little as 30 minutes before sex. Prolonged erections can be dangerous. We considered cost, medications available, and whether generic versions were offered to help reduce costs. Follow the manufacturer’s directions to use and clean the oral syringe.AdSave Time & Money with Online Prescription for Viagra, Cialis, Sildenafil and Tadafil. Free & Private Online Consultant with Real Doctors. Reliable E.D. Meds Shipped test1.ru Shipping · Real Doctors · Discreet Packaging · Personalized PlanTypes: Erectile Dysfunction · Immune Support · Hair Growth · Sertraline. Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour. Examples of Viagra’s more commonly reported side effects include: headache. flushing (temporary warmth, redness, or deepening of skin color) stuffy nose. indigestion (upset stomach) mild vision.