Normal Dose of Cialis (Tadalafil) for Erectile Dysfunction
For most men with erectile dysfunction, start with tadalafil 10 mg taken as needed prior to sexual activity, which can be adjusted to 20 mg for better efficacy or decreased to 5 mg if side effects occur. 1
As-Needed Dosing (Preferred for Most Patients)
The FDA-approved starting dose is 10 mg taken prior to anticipated sexual activity, with dose adjustment between 5-20 mg based on individual response and tolerability. 1
Maximum dosing frequency is once per day for most patients. 1
Tadalafil improves erectile function for up to 36 hours after dosing, allowing flexibility in timing of sexual activity. 1
At the 20 mg dose, 75% of intercourse attempts are successfully completed compared to placebo, with 81% of men reporting improved erections. 2
The 10 mg dose produces mean successful intercourse rates of 57%, while 20 mg achieves 62% success rates. 3
Once-Daily Dosing (Alternative Option)
For men who prefer spontaneous sexual activity without timing medication, start with tadalafil 2.5 mg once daily, which can be increased to 5 mg daily based on efficacy and tolerability. 1
Daily dosing eliminates the need to plan sexual activity within a specific timeframe. 4, 5
Both 2.5 mg and 5 mg daily doses produce statistically significant improvements in erectile function, with the 5 mg dose showing slightly better efficacy. 6, 5
Key Dosing Considerations
Unlike sildenafil and vardenafil, tadalafil does NOT show dose-dependent improvement in erectile function between 5 mg, 10 mg, and 20 mg doses. 7, 4 This means:
The choice between 10 mg and 20 mg should be based primarily on tolerability rather than expecting dramatically better efficacy at higher doses. 7
If 10 mg is ineffective, increasing to 20 mg may help some patients, but consider other factors like inadequate sexual stimulation or timing issues first. 4
Special Population Adjustments
Renal Impairment (As-Needed Dosing): 1
- Creatinine clearance 30-50 mL/min: Start with 5 mg, maximum 10 mg once every 48 hours
- Creatinine clearance <30 mL/min or hemodialysis: Maximum 5 mg once every 72 hours
Hepatic Impairment: 1
- Mild to moderate (Child-Pugh A or B): Maximum 10 mg once daily
- Severe (Child-Pugh C): Not recommended
Critical Safety Requirements
Tadalafil is absolutely contraindicated with any form of nitrate medication due to risk of potentially fatal hypotension. 4, 1
Wait 48 hours after tadalafil before administering nitrates in emergency situations (compared to 24 hours for sildenafil). 4
Sexual stimulation is necessary for tadalafil to be effective—the medication does not work without arousal. 4
Defining Treatment Failure
An adequate trial requires at least 5 separate attempts at maximum dose before declaring tadalafil ineffective. 4
Many apparent failures are due to improper use, inadequate sexual stimulation, or modifiable factors rather than true medication failure. 4
If tadalafil fails after an adequate trial, consider switching to a different PDE5 inhibitor (sildenafil or vardenafil) before moving to second-line therapies. 4
Common Pitfalls to Avoid
Do not split tadalafil tablets—the entire dose must be taken. 1
Tadalafil may be taken without regard to food, unlike sildenafil which is affected by high-fat meals. 1
For men with diabetes or post-prostatectomy, expect more severe baseline ED and potentially less robust response to PDE5 inhibitors. 4