Soon, in , ICOS received a patent for compound IC structurally unlike sildenafil and vardenafil , and Phase 1 clinical trials began in Cialis can last in the system for up to 36 hours. In some cases, online ED providers accept health insurance. Erectile dysfunction can be caused by a variety of factors , including age, cardiovascular problems, diabetes, and other conditions that affect nerve function or blood flow. It’s available in 25 mg, 50 mg, and mg tablets and lasts up to 18 hours.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. The active ingredient of Cialis is tadalafil. It’s available as the generic drug tadalafil.A generic drug is considered to be as safe and effective as the original drug. And generics tend to. The drug comes in low-dose versions that can be taken daily. This means you can have sex at any time, rather than needing to take a pill from time to time as needed like other ED brands. The starting dose for daily-use Cialis is milligrams (mg). If that doesn’t work, you can increase your daily dose up to 5 mg.