Generic Viagra (sildenafil) is an alternative to the branded Viagra drug that can be used for treating erectile dysfunction (ED). It’s now sold by many manufacturers, including online.Remove the syringe from the bottle. This boosts blood flow and helps you get an erection from sexual activity. Your doctor or other health care professional can recommend one for you based on these factors, other health conditions you have and any other medicines you take. Follow your doctor’s orders or the directions on the label. Push the plunger of the syringe, then insert the tip into the bottle while holding the bottle upright on a flat surface. Oral ED medicines might not work or might be dangerous if you also take any of the following: Nitrate medicines. Sildenafil Viagra.You should also avoid products you can buy online without a prescription that claim either to be generic forms of sildenafil or to contain sildenafil. (Sildenafil is the active drug in . For treatment of erectile dysfunction: For oral dosage form (tablets): Adults up to 65 years of age—50 milligrams (mg) as a single dose no more than once a day, 1 hour before sexual . Valid at all major chains including Walgreens, CVS Pharmacy, Target, WalMart Pharmacy, Duane Reade and 65, pharmacies nationwide. No manufacturer promotions could be .It might work longer if you have mild to moderate erectile dysfunction. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail. However, the dose is usually not more than 80 mg 3 times a day. Tadalafil Cialis. Remove the cap by pushing it down and twisting it counter-clockwise.