Cialis (tadalafil) can be taken in two main ways: as-needed for erectile dysfunction (ED) or once daily for ED (and sometimes for BPH urinary symptoms). This page explains the core dosing logic, how to choose between strategies, and the most important safety rules that influence dosing decisions.

Table of Contents

Cialis Dosage: The Two Main Strategies

1) As-Needed Cialis (On-Demand)

This approach is taken before sexual activity to support erections during a response window.

Typical idea:

A dose is taken on days you expect sexual activity
The effect window can remain available for many hours (see here C4)

As-needed Cialis is mainly used for ED where the user prefers planned dosing.

2) Daily Cialis (Once-Daily)

This approach is taken every day, usually at the same time, to maintain more consistent tadalafil exposure.

Daily Cialis is often used when:

Sexual activity is frequent and spontaneity is preferred
ED is ongoing and a “ready anytime” approach fits lifestyle
BPH symptoms are present (Cialis can help urinary symptoms when used daily)

Common Strengths People See (Practical Context)

Depending on your clinic/pharmacy and indication, Cialis/tadalafil is often associated with:

Lower daily doses (commonly 2.5 mg or 5 mg)
Higher as-needed doses (commonly 10 mg or 20 mg)

The “right” dose depends on response, tolerability, and safety profile.

How Clinicians Typically Choose a Dose (The Logic)

Dosing selection generally considers:

1) Your goal (ED only vs ED + BPH)

ED only: daily or as-needed can work
ED + BPH: daily is often preferred to support urinary symptoms

Read: (Uses) and later (Cialis for BPH).

2) Frequency of sexual activity

Occasional → as-needed often fits
Frequent → daily often fits

Read: (Daily vs As-Needed).

3) Side-effect tolerance

Some users need a lower dose due to:

Headache
Flushing
Indigestion
Nasal congestion
Back/muscle pain (notably associated with tadalafil)

Read: (Common Side Effects).

4) Medication interactions and cardiovascular risk

Dosing is not only about effectiveness-safety is the main limiter.

If you use certain medicines (especially nitrates), Cialis may be unsafe regardless of dose.

Read: (Warnings) and (Drug Interactions).

Dose Timing: What Matters for Results

Even a “correct” dose can feel ineffective if timing is wrong.

As-needed Cialis needs enough time to start working (see here)
Daily Cialis works best when taken consistently (same time daily concept)

Dose Adjustments (High-Level)

Some people require dose adjustments or may not be suitable candidates for standard dosing, such as those with:

Kidney disease
Liver disease
Certain cardiovascular conditions
Use of interacting medicines that raise tadalafil exposure

This is why “copying a friend’s dose” is risky and why medical review matters.

What NOT to Do (Common Dosing Mistakes)

These errors cause side effects, poor results, or dangerous interactions:

❌ Do not take more than prescribed hoping it will work faster
❌ Do not double dose if you think the first dose “didn’t work”
❌ Do not mix Cialis with other PDE5 inhibitors (e.g., sildenafil)
❌ Do not combine with nitrates or recreational “poppers”
❌ Do not use heavy alcohol to “relax” — it can worsen dizziness/low BP and reduce performance

If Cialis is “not working,” the solution is usually timing, stimulation, dose review, or addressing underlying causes, not stacking doses.