· 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 intercourse. .For erectile dysfunction, it’s best to take sildenafil on an empty stomach. Sorry something went wrong with your subscription Please, try again in a couple of minutes Retry. Use only the brand of this medicine that your doctor prescribed. If your dose is different, do not change it unless your doctor tells you to do so. Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection.Sildenafil Prices, Coupons and Patient Assistance Programs. Sildenafil is a member of the agents for pulmonary hypertension drug class and is commonly used for Erectile Dysfunction, Pulmonary Arterial Hypertension, and Sexual Dysfunction – SSRI Induced.. Brand names for sildenafil include Viagra, Revatio, and Liqrev. The cost for sildenafil . 1 day ago · How much does Viagra cost online? What dosage is available? Hims: yes: yes – starting at $ per dose of Viagra – $4–$10 per dose of sildenafil, depending on dosage: 25– mg.  · a light-headed feeling, like you might pass out. Common sildenafil side effects may include: flushing (warmth, redness, or tingly feeling); headache, dizziness; heartburn, nausea, or upset stomach. abnormal vision (blurred vision, changes in color vision) runny or stuffy nose, nosebleeds; sleep problems (insomnia); or.This medicine usually begins to work for erectile dysfunction within 30 minutes after taking it. You’ll soon start receiving the latest Mayo Clinic health information you requested in your inbox. Never take an extra dose to make up for a forgotten one. The as-needed dose is usually 10 mg but can range from 5—20 mg. Cialis can be taken daily, providing constant treatment for ED for people who have sex frequently. Push the plunger of the syringe, then insert the tip into the bottle while holding the bottle upright on a flat surface.