Tadalafil (Cialis) Dosages: Daily vs As-Needed Strengths
Tadalafil is unusual among ED medications because it is approved for two different dosing patterns: a low daily dose, and a higher as-needed dose. This page explains the available strengths, how prescribers choose between daily and as-needed dosing, timing, and the factors that can change the right dose for a given patient.
Standard Tadalafil Strengths
| Strength | Typical Pattern | Notes |
|---|---|---|
| 2.5 mg | Daily use | Lower daily starting dose |
| 5 mg | Daily use | Most common daily-dose strength |
| 10 mg | As-needed use | Typical as-needed starting dose |
| 20 mg | As-needed use | Maximum approved as-needed dose |
Daily Dosing vs. As-Needed Dosing
With daily dosing, a low strength (2.5 mg or 5 mg) is taken at roughly the same time each day, regardless of anticipated activity, which keeps a steady, low level of the drug in the body and removes the need to plan timing around sexual activity. With as-needed dosing, a higher strength (10 mg or 20 mg) is taken only before an anticipated occasion, similar to how sildenafil is typically used. Neither pattern is universally “better” — the choice usually comes down to frequency of activity, tolerance of a daily medication, and cost, and is a decision made together with a prescriber.
Key point: Tadalafil is the only widely prescribed ED medication with an FDA-approved daily-dosing option in addition to as-needed use.
Switching Between Patterns
Patients sometimes start with as-needed dosing and later switch to daily dosing, or the reverse, based on how their pattern of activity or side effects changes over time. This switch requires a new prescription and conversation with the prescriber, since the strengths used for each pattern differ and are not simply interchangeable at the same dose.
Timing
For as-needed dosing, tadalafil is typically taken at least 30 minutes before anticipated activity, though because of its long duration, exact timing is less critical than with shorter-acting medications. For daily dosing, the tablet is taken at approximately the same time each day so that a steady blood level is maintained. Unlike sildenafil, tadalafil's absorption is largely unaffected by food, so it can be taken with or without a meal without a major difference in onset.
Maximum Frequency
Regardless of dosing pattern, tadalafil should not be taken more than once in a 24-hour period. For daily dosing this is straightforward since it is a fixed daily schedule; for as-needed dosing it means waiting at least 24 hours between individual as-needed doses.
Important: Tadalafil must never be combined with nitrate medications at any dose, whether used daily or as needed. This combination can cause a dangerous drop in blood pressure.
Factors That Can Change the Right Dose
- Kidney or liver impairment: reduced function often leads to a lower starting dose or, for daily dosing, avoidance of the daily pattern in favor of as-needed use.
- Alpha-blockers: similar to sildenafil, combined use can compound blood pressure effects, prompting dose or timing adjustments.
- CYP3A4-inhibiting medications: certain antibiotics and antifungals can raise tadalafil levels, prompting a lower dose or reduced frequency.
- Age: older adults may start at a lower strength within either dosing pattern.
For a full comparison of how tadalafil differs from sildenafil in onset and duration, see our Viagra vs Cialis comparison, or for help deciding which pattern of use might fit your routine, see our daily-use decision guide.