Hi. So did you take the dose as prescribed by your doctor? That's within the range of dosing offered. But not likely where someone is started if you are new to it. Has it worked for you before? One of the biggest issues with it working properly is timing of sex. Too soon, won't work right. Too long after taking it, won't work right. Another way it is prescribed to help is to take a lower dose (often 2.5 mg) but every day at the same time each day.Then it is in your system. That's alternate way to take it that you can talk to your doctor about. Do not take more than 20 mg. Upping your dose at this point shouldn't be done unless your doctor gives you the okay. But likely they will not. https://www.medicalnewstoday.com/articles/drugs-cialis-dosage#factors-affecting-dosage If it is determined that cialis isn't going to work for you, there are other treatments. Certainly more will be done to help you. By the way, is there an origin that is known for your ED? Often psychological help along the way can be beneficial too. But if cialis or viagra don't work for you, there are second line treatments to explore.