Pfizer Canada Inc. If so, how much? Food and Drug Administration has approved fifteen drug manufacturers to market generic sildenafil in the United States. What medications do you take, including any herbal remedies or supplements? Keep from freezing.AdGet a Prescription for ED treatment, discreetly deliverED to your ive Offers · How It Works · Get More Info4/5 ( reviews)Types: Finasteride · Shipping Policy · Tadalafil · Sildenafil. Viagra comes as tablets that you take by mouth, when needed. Available strengths: 25 mg, 50 mg, mg Viagra comes in these strengths: 25 milligram (mg), 50 mg, and mg. Erectile dysfunction is when a man has difficulty getting an erection or keeping it long enough for sex. It’s also known as ED or impotence. It happens when not enough blood flows to the penis, preventing an erection. The frequency increases with age, affecting about 50% of men over age 40*; however younger men may also experience ED.