Tadalafil – Wikipedia The available doses of tadalafil are 2.5 mg, 5 mg, 10 mg, and 20 mg. The dose that is prescribed will vary depending on a few factors such as: Age. Type and Dosage and Administration. Cialis typically comes in 10 mg and 20 mg dosages for as-needed use. However, Cialis is available in 2.5 mg and 5 mg for daily use. Cialis (tadalafil) increase increases blood flow to a certain area of the body and is used to treat erectile dysfunction (impotence). Includes Cialis side effects medication cialis dosage Generic name: Tadalafil Tablets (Cialis) [ tah-DA-la-fil ] Brand name: Cialis Drug classes: …