One of these is PAH. It’s available in 10 mg and 20 mg tablets. Persons surnamed “Cialis” objected to Eli Lilly and Company’s so naming the drug, but the company has maintained that the drug’s trade name is unrelated to the surname. How Does Cialis Work? However, all medications come with risks.stockcam / Getty Images What is generic Cialis? Generic Cialis is called tadalafil, which is the active ingredient in Cialis. Cialis is Food and Drug Administration (FDA) approved to treat. How much does it cost? Does it cause any side effects? We’ll answer all of those important questions below. GoodRx Health Promotion disclosureinfoPromotion disclosureinfo Save up to 97% on tadalafil cialis with GoodRxDifferent pharmacies offer different prices for the same medication. GoodRx helps find the best price for you. As needed for ED: 5 to 20 mg by mouth as a one-time dose, with a maximum of one dose in 24 hours. Effects may last up to 36 hours. Daily dosing for ED: or 5 mg by mouth daily. For daily dosing, the maximum dose is 5 mg per day. The medication should be taken once daily at about the same time every day to maintain a consistent level of.