However, eating food, particularly high-fat food, can reduce the effectiveness of Viagra. Cialis is available in two forms: As a daily-use medication in dosages of 2. Cialis with food Cialis can be taken with or without food. Cialis contains 10mg or 20mg of the active ingredient tadalafil. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Because they are the same class of medications, they have similar side effects and effectiveness. Treated trusted source Brock, G.Cialis Dosages. The most appropriate Cialis dose for you will depend on your needs, your healthcare provider’s assessment and how well you respond to the medication. Cialis is available in two forms: As a daily-use medication in dosages of mg and 5mg. For use as needed in dosages of 10mg and 20mg. Extra 15% off $30 sitewide with code SAVE15; Clip your mystery deal! BOGO 50% off select Walgreens health & wellness. Check your prescription Make sure the following details match. Choose your pharmacy phone Need help? Show this coupon to your pharmacist Print or send this coupon to yourself. Free GoodRx coupon Free to use. No sign-up required. See more.