Tadalafil Dosage: Recommended Doses for ED and Daily Use
The correct tadalafil dose depends on whether the medicine is taken when needed or as a once-daily treatment.
For erectile dysfunction, the usual on-demand starting dose is 10mg taken before activity. If that is not effective enough, a prescriber may increase it to 20mg. For regular treatment, tadalafil is commonly prescribed as 5mg once daily, with 2.5mg used where 5mg is not well tolerated.
The same 5mg daily regimen is used for urinary symptoms linked to benign prostatic hyperplasia, and for men being treated for both conditions.
Choosing the right dose matters because it affects both how well treatment works and how safely it is used.
Key things to know
- On demand: 10mg to start, increasing to 20mg if needed. 20mg is the maximum
- Daily: 5mg once a day, reducible to 2.5mg for tolerability
- For benign prostatic hyperplasia, and for both conditions together: 5mg once daily
- Tadalafil should not normally be taken more than once per day
- A larger milligram number does not automatically mean a more appropriate dose
- Kidney or liver problems, other medicines and cardiovascular health can all change what dose is suitable
The Available Strengths
Tadalafil tablets used for erectile dysfunction come in four strengths, each designed for a different dosing strategy.
| Strength | Primary role |
|---|---|
| 2.5mg | Lower once-daily dose for erectile dysfunction |
| 5mg | Usual once-daily dose for erectile dysfunction and for benign prostatic hyperplasia |
| 10mg | Usual starting dose for on-demand treatment |
| 20mg | Maximum standard on-demand dose |
On-Demand Dosing
For tadalafil taken only when required, the normal starting dose is 10mg before anticipated activity.
If 10mg has been used correctly but does not provide an adequate response, a clinician may consider 20mg. It should not be taken more than once per day.
20mg should not automatically be selected first simply because it is stronger. Using the lowest effective dose helps balance benefit against side-effect risk.
When to Take 10mg
Tadalafil 10mg is generally taken at least 30 minutes before anticipated activity. Some people prefer to take it earlier, since tadalafil's long duration means precise timing is not required.
Its effectiveness can persist for up to approximately 36 hours after an on-demand dose. That does not mean an erection remains present for 36 hours. It means tadalafil may continue to support the normal erectile response during that period when stimulation occurs.
Is 20mg Twice as Effective as 10mg?
No. A 20mg tablet contains twice as much tadalafil, but clinical effectiveness does not increase in a one-to-one relationship with dose.
Some people who do not get an adequate response at 10mg benefit from an increase. Others experience little additional benefit, or more side effects.
The goal is the lowest appropriate dose that provides a reliable response with acceptable tolerability, not the highest possible one.
Can You Take More Than 20mg?
Not under the standard regimen. 20mg is the maximum on-demand dose.
If 20mg repeatedly fails despite correct use, taking more is not the next step. A clinical review should instead consider whether enough time was allowed, whether appropriate stimulation occurred, alcohol use, other medicines, the underlying causes, and whether another treatment would be more appropriate.
Increasing beyond the recommended dose can increase side effects without providing predictable additional benefit.
Daily Dosing
The standard daily dose for erectile dysfunction is 5mg once daily, taken at approximately the same time each day.
It produces a lower but continuous exposure compared with taking 10mg or 20mg on demand.
Daily dosing may be considered when treatment is expected to be used frequently, such as around twice a week or more. It can also suit someone who prefers less advance planning, or a regular routine rather than a tablet before each occasion.
The appropriateness of long-term daily treatment should be reviewed periodically.
What 5mg Is Used For
5mg has three roles: daily treatment for erectile dysfunction, treatment for benign prostatic hyperplasia, and treatment where both occur together.
For all three, the usual regimen is 5mg once daily, taken with or without food.
A higher 10mg or 20mg dose should not be used simply because urinary symptoms remain troublesome.
When 2.5mg Is Used
2.5mg is a lower once-daily dose for erectile dysfunction, considered when 5mg provides benefit but causes side effects that make continued treatment difficult.
It is not an on-demand dose. Someone taking tadalafil only occasionally would normally use the on-demand regimen instead.
It is also not the established dose for benign prostatic hyperplasia. Its effectiveness for that has not been established in the same way, so someone who cannot tolerate 5mg may need a different treatment rather than a reduced tadalafil dose.
Comparing the Doses
5mg or 10mg?
They are usually used differently. 5mg is primarily a once-daily treatment, and 10mg is primarily on demand.
Someone who needs treatment occasionally may prefer 10mg when required. Someone who wants frequent treatment, or less planning, may prefer 5mg daily.
Neither is automatically better. The choice depends on treatment frequency, response, side effects and preference.
10mg or 20mg?
Treatment generally begins at 10mg for on-demand use, with 20mg considered when that is insufficient.
If 10mg already provides a reliable response, increasing may give little benefit while potentially increasing side effects. The higher dose should be used because it is needed, not because it is available.
Daily or On Demand?
The two strategies summarise simply. Daily treatment is 5mg once daily, potentially reduced to 2.5mg. On-demand is 10mg to start, potentially increased to 20mg.
The daily regimen maintains exposure. The on-demand regimen uses a larger individual dose before anticipated activity.
These regimens should not be combined independently.
Can You Take 10mg or 20mg Every Day?
Neither is recommended for continuous daily treatment. Both are intended primarily for on-demand use.
If daily therapy is clinically appropriate, the usual regimen is 5mg once daily. Taking 20mg continuously could substantially increase exposure and side-effect risk.
Do not create your own daily schedule using an on-demand strength.
Frequency and Timing
Tadalafil should generally not be taken more than once per day. That applies whether the dose is 5mg daily, 10mg on demand or 20mg on demand.
Taking another tablet later the same day because the first did not appear to work is not recommended.
Tadalafil has a half-life of approximately 17.5 hours, meaning substantial medicine can remain in the body long after the initial tablet. That is one reason repeat dosing should not be based on whether the immediate effect appears to have worn off.
Taking Two Tablets
Only take the number and strength specified by your prescribed regimen, since two tablets can represent very different doses.
- Two 5mg tablets provide 10mg
- Two 10mg tablets provide 20mg
- Two 20mg tablets provide 40mg, which is above the standard maximum
Do not calculate your own dose by combining tablets unless a prescriber or pharmacist has specifically instructed you to.
If You Take Too Much
Taking more than prescribed can increase the risk of side effects including headache, indigestion, flushing, dizziness, back pain, muscle pain, low blood pressure and a prolonged erection.
If you accidentally take more than prescribed, do not take additional doses, and seek medical advice. Serious symptoms require urgent assessment.
If You Miss a Daily Dose
Take it when you remember, unless it is almost time for your next scheduled dose. If the next dose is close, skip the missed tablet and continue normally.
Do not take two doses together to compensate, which could result in excessive exposure.
If It Does Not Work
Do not immediately take another tablet. First consider whether enough time was allowed, whether appropriate stimulation occurred, whether excessive alcohol was involved, whether the medicine was taken correctly, and whether another condition or medicine is interfering.
If 10mg repeatedly provides inadequate benefit despite correct use, 20mg may be considered after clinical assessment.
If 20mg repeatedly fails, do not increase beyond it. That warrants a broader assessment of the underlying cause, cardiovascular risk, hormone status where relevant, interactions, psychological contributors, technique and alternative treatments.
What Changes the Right Dose
Food
Tadalafil can be taken with or without food, and food does not meaningfully change absorption.
There is normally no need to take it fasting, avoid dinner, or alter timing because of a high-fat meal. That differs from some shorter-acting PDE5 inhibitors.
Alcohol
Alcohol does not automatically require a different dose, but excessive amounts can increase dizziness, light-headedness and blood pressure lowering, and can independently make erectile function less reliable.
Do not take extra tadalafil to compensate for an inadequate response after heavy drinking.
Age
Age alone does not normally require a dose adjustment. An older adult does not automatically need 5mg instead of 10mg simply because of age.
However, older adults may be more likely to have kidney impairment, cardiovascular disease, multiple medicines or blood pressure problems, all of which can affect what dose is appropriate.
Kidney Problems
For mild to moderate kidney impairment, dose adjustment is generally not required for on-demand treatment.
For severe impairment, the maximum on-demand dose is generally 10mg, and once-daily treatment is not recommended at all.
That is because exposure increases when kidney function is significantly reduced. Because daily treatment involves repeated dosing and tadalafil has a long half-life, exposure can accumulate, and dialysis does not effectively remove a substantial amount.
Liver Problems
For on-demand treatment in people with liver impairment, 10mg is generally the recommended dose. There are limited data supporting doses above that.
Daily tadalafil has not been adequately evaluated in liver impairment either, so the prescriber needs to assess benefits and risks individually.
Someone with liver disease should not increase from 10mg to 20mg without appropriate specialist consideration.
Diabetes
Diabetes itself does not normally require a dose adjustment.
However, it can be associated with kidney disease, cardiovascular disease, blood pressure treatment and more severe erectile dysfunction, all of which may affect treatment selection.
Interactions That Affect Dosing
Nitrates and Riociguat
Tadalafil must not be combined with nitrate medicines or nitric oxide donors, because the combination can cause a potentially dangerous reduction in blood pressure.
That applies at every dose, including 2.5mg and 5mg. Using a lower dose does not make the combination safe.
The same applies to riociguat, which produces additive blood-pressure-lowering effects. That combination is contraindicated, and a lower dose does not remove the interaction.
Blood Pressure Medicines and Alpha Blockers
Tadalafil can add to the blood-pressure-lowering effects of some antihypertensive medicines. That does not mean everyone taking one must avoid tadalafil, but the exact medicines, doses and cardiovascular status need reviewing.
Alpha blockers also lower blood pressure, and combining them with tadalafil can increase dizziness, light-headedness, fainting and symptomatic low blood pressure. That combination should be assessed individually.
Antibiotics and Other Medicines
Some antibiotics and other medicines change tadalafil concentrations by affecting the CYP3A4 enzyme system.
Medicines that inhibit CYP3A4 may increase exposure and side-effect risk. Medicines that increase its activity may reduce exposure.
Always mention temporary medicines, including antibiotics, during a review.
Other PDE5 Inhibitors
Do not independently combine tadalafil with sildenafil, vardenafil or avanafil.
Combining them can increase total PDE5 inhibition, and with it headache, flushing, dizziness, low blood pressure and the risk of a prolonged erection.
If tadalafil is not working adequately, the regimen should be reviewed rather than supplemented.
Different Conditions, Different Doses
Knowing which condition tadalafil is being prescribed for matters, because the regimens differ.
| Use | Dose |
|---|---|
| Erectile dysfunction, on demand | 10mg to start, 20mg where necessary |
| Erectile dysfunction, daily | 5mg once daily, sometimes 2.5mg for tolerability |
| Benign prostatic hyperplasia | 5mg once daily |
| Both together | 5mg once daily |
Tadalafil is also used under specialist supervision for pulmonary arterial hypertension, on an entirely different regimen that can involve 40mg once daily. That is a specialist dose and should never be read as evidence that 40mg is appropriate for erectile dysfunction. The standard maximum on-demand dose remains 20mg.
What Is the Best Dose?
There is no single best dose for everyone.
The best dose is the lowest clinically appropriate amount that provides sufficient benefit with acceptable side effects.
For many people starting on-demand treatment, that means 10mg. For someone needing frequent treatment, 5mg once daily may be more appropriate. For an inadequate response to 10mg, 20mg may be considered. For someone who does not tolerate 5mg daily, 2.5mg may sometimes suit better.
Dose selection should be personalised rather than based on choosing the strongest tablet.
