Methodology We researched 19 online platforms for erectile dysfunction treatment to learn more about the process of ordering ED pills online. Protein binding is independent of total drug concentrations. The possible categorical responses to these questions were 0 no attempted intercourse, 1 never or almost never, 2 a few times, 3 sometimes, 4 most times, and 5 almost always or always. The titration studies, in which most patients received mg, showed similar results. Doses for children can range from 10mg to 20mg taken 3 times a day, depending on their weight. Sildenafil at steady state, at a dose not approved for the treatment of erectile dysfunction 80 mg t.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. Sildenafil tablets for erectile dysfunction come in different strengths ranging from 25mg to mg. The usual dose is 50mg, when you need it. Do not take it more than once a day. The dose can be increased to mg or decreased to 25mg depending on its effect. Take sildenafil up to 4 hours before you want to have sex. Cialis lasts up to 36 hours in the body, while Viagra lasts 4–6 hours in the body. Both are taken 30 minutes before sex. Cialis can cause limb pain, while Viagra can cause vision change, rash.