What Is Cialis?

Cialis is a brand name for tadalafil, an FDA-approved PDE5 inhibitor for erectile dysfunction. As-needed use can last longer than sildenafil for many men. A separate lower-dose daily option exists when a clinician decides that approach fits.

Written by Virantus Editorial Team

Medically reviewed by Virantus Clinical Team · Reviewed August 2026

Last updated August 2026

Cialis and tadalafil

Cialis is the brand name; tadalafil is the active ingredient. Generic tadalafil may be prescribed when appropriate. Like other PDE5 inhibitors, tadalafil helps increase blood flow during sexual stimulation — arousal is still required.

Tadalafil has a longer half-life than sildenafil, which is why some men describe more flexibility around timing.

Daily vs as-needed

As-needed tadalafil is taken before anticipated sexual activity, with effects that can last up to about 36 hours for some men. Daily tadalafil uses a lower dose on a regular schedule so the medicine is always present at a baseline level.

Neither approach is universally better. A clinician chooses based on your health, frequency of sexual activity, and side-effect tolerance. Do not invent a daily schedule from an as-needed prescription.

Safety considerations

Tadalafil must not be combined with nitrate medications. Common side effects include headache, flushing, and indigestion. A licensed clinician reviews your full medication list and cardiovascular status before prescribing.

This page is educational — not prescribing guidance.

Common questions

Yes. Tadalafil is the active ingredient in Cialis. Generic tadalafil contains the same ingredient when dispensed appropriately.

Sources

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