FDB disclaims all warranties, whether expressed or implied, including any warranty as to the quality, accuracy, and suitability of this information for any purpose. How Effective Is Cialis? Which Is More Effective? Cialis is a brand-name prescription medication. Obesity Additionally, certain risk factors increase the risk of ED, such as smoking , lack of exercise, and drug or alcohol use.Tadalafil: 5 mg, 10 mg, or 20 mg, taken as needed; Cialis: mg, 5 mg, 10 mg, and 20 mg, taken as needed; The cost of the medication is from $ per month for Cialis and from $40 per month for. The lowest price on for generic Cialis (tadalafil) 20 mg is $ per tablet for 88 tablets at PharmacyChecker-accredited online pharmacies. Lowest U.S. Pharmacy Coupon Price: $ per tablet for 90 tablets. . Dosage. The dose of Cialis you need will depend on whether you’re taking it daily or as needed. Daily doses are often between and 5 milligrams (mg). The as-needed dose is usually 10 mg but can range from 5–20 mg. The typicaldose of Viagra is 50 mg. However, the dosage can range from 25– mg.