Tadalafil 5 mg: What the Daily Dose Is For

The 5 mg tablet is the daily-use strength on the Cialis label. Uses, trial numbers and the limits that apply.

Tadalafil 5 mg is the tablet strength the Cialis label ties to once-a-day use. It is the labeled dose for the urinary symptoms of an enlarged prostate (BPH), and for men with both ED and BPH. For ED alone, the label starts once-daily dosing at 2.5 mg and allows an increase to 5 mg based on response and tolerability.¹ It is not an "as needed" dose: the label's as-needed range for ED runs from 5 mg up to 20 mg, taken before sexual activity.¹ What follows is what the label and the trials say about 5 mg specifically.

What is tadalafil 5 mg used for?

The Cialis label lists three once-daily uses. Each has its own written dose:¹

The tablets themselves come in 5, 10 and 20 mg.¹ So 5 mg is the lowest tablet strength on the label, and the daily regimens above are built around it. Our guide to sildenafil 20 mg shows a similar trap in another drug: the strength on a pharmacy listing belongs to a specific label with a specific schedule.

How is daily 5 mg different from taking tadalafil as needed?

The difference is the schedule, not the drug. With once-daily dosing, steady blood levels are reached within 5 days, and exposure is about 1.6 times higher than after a single dose.¹ The mean terminal half-life is 17.5 hours.¹ The label says the tablet may be taken with or without food, and that food does not change how much is absorbed.¹

A 2017 meta-analysis of six randomized trials (1,534 men) compared once-a-day tadalafil with on-demand tadalafil for ED. It found no difference in the erectile function domain score of the IIEF questionnaire. The once-a-day arms did better on two diary questions, penetration and maintenance of erection, and adverse events were similar between the schedules.² A smaller randomized trial in 44 evaluable men with ED after radiotherapy for prostate cancer compared 20 mg on demand with 5 mg daily for 12 weeks. Both groups improved, with mean erectile function scores of 25 and 27.1 (not a significant difference), and the daily group reported better adherence.³ That trial was small and phase II, so it supports the idea that the schedules are comparable, not that one is better.

How much did 5 mg help in the label trials?

For ED, the Cialis label reports two placebo-controlled once-daily studies. In the 24-week US study, the erectile function domain score rose by 1.2 points on placebo, 6.1 on 2.5 mg and 7.0 on 5 mg. In a 12-week study outside the US, it rose 0.9 on placebo and 9.7 on 5 mg.¹ The share of attempts with successful maintenance of erection rose by 10 percentage points on placebo and 35 points on 5 mg in the longer study.¹ These are averages from manufacturer-run trials, and an individual man can do better or worse than the average.

For BPH, two 12-week trials measured the International Prostate Symptom Score, where lower is better. The 5 mg group's score fell by 4.8 points against 2.2 on placebo in one study, and by 5.6 against 3.6 in the other.¹ Peak urine flow rate did not differ significantly from placebo in the study that reported it as a secondary measure (1.6 against 1.2 mL/sec).¹ In other words, symptom scores improved more than flow measurements did. Our page on ED pills and blood pressure medicines covers the related question of other prescriptions taken alongside tadalafil.

What side effects are listed for 5 mg?

In the 24-week ED study, the adverse reactions reported by at least 2% of men on 5 mg and more often than on placebo were nasopharyngitis (6%), gastroenteritis (5%), upper respiratory infection (4%), nasal congestion (4%), hypertension (3%), and reflux (2%). The placebo group had 94 men and the 5 mg group 97.¹ In three 12-week BPH-related studies (581 men on 5 mg, 576 on placebo), headache was reported by 4.1% on tadalafil against 2.3% on placebo, dyspepsia by 2.4% against 0.2%, and back pain by 2.4% against 1.4%.¹ In those BPH-related studies, stopping because of an adverse event was more common on tadalafil than placebo, at 3.6% against 1.6%.¹

The label notes that back pain or muscle aches usually appear 12 to 24 hours after a dose and typically clear within 48 hours.¹ Sudden loss of vision or hearing means stopping the drug and getting medical help at once, and an erection lasting more than four hours needs emergency care.¹

Who should not take daily tadalafil, or needs a different dose?

Several limits are written into the label for once-daily use:¹

• Nitrates in any form are contraindicated, whether taken regularly or occasionally. If a man on tadalafil needs a nitrate in a life-threatening situation, at least 48 hours should have passed since the last dose.¹
• Kidney function: with creatinine clearance of 30 to 50 mL/min, the label starts at 2.5 mg and allows 5 mg based on response. Below 30 mL/min, once-daily use is not recommended.¹
• Liver disease: once-daily use has not been extensively studied in mild or moderate impairment, so caution is advised; severe impairment is not recommended.¹
• Strong CYP3A4 inhibitors such as ketoconazole or ritonavir cap the once-daily dose at 2.5 mg.¹
• Alpha-blockers: for BPH, the label does not recommend taking tadalafil with them. For ED, a man should be stable on the alpha-blocker first and start at the lowest dose.¹

The label also says combinations of tadalafil with other PDE5 inhibitors or other ED treatments have not been studied.¹ The wider picture of drug interactions is in our ED medication interactions guide.

Can you take 5 mg tadalafil with sildenafil or other ED drugs?

The labels advise against it. The Cialis label states that the safety and efficacy of combining it with other PDE5 inhibitors have not been studied and tells patients not to take it with them.¹ The Viagra label says the same of combinations with other ED treatments and adds that they may further lower blood pressure.⁴ The full label comparison is in sildenafil and tadalafil together.

Compounded options: Quattro from Vea Health (sponsored)

We have a financial relationship with Vea Health, so this section is a sponsored placement. It is here because some readers searching for a 5 mg tablet are really asking how a different route to ED treatment compares. Vea Health describes Quattro as a compounded sublingual dose combining sildenafil, tadalafil, vardenafil and apomorphine, prescribed only after a licensed clinician reviews a health history.⁵

Quattro is not a 5 mg tadalafil tablet and not a once-daily regimen. The page we loaded does not list strengths, so we cannot say how much tadalafil it contains. It is compounded, so the FDA has not reviewed it for safety, effectiveness or quality, and the Cialis and Viagra labels say that combinations like it have not been studied.⁶¹⁴ We make no claim that it is stronger, faster or safer than tadalafil. A man with BPH symptoms, kidney or liver disease, or an alpha-blocker or nitrate prescription needs a clinician to decide whether any of this is appropriate for him.

Questions to ask a prescriber about 5 mg

• Is this for ED, for urinary symptoms, or for both, and does that change the dose?
• Do any of my medicines contain nitrates, or are any of them alpha-blockers?
• Do my kidney or liver tests change the dose?
• If I want to try as-needed dosing instead, how would the plan change?
• When should I expect to judge whether it is helping, given that blood levels build for about 5 days?

Questions readers ask

Is tadalafil 5 mg a daily dose?

Yes. The Cialis label ties 5 mg to once-a-day use at about the same time each day: for BPH, for ED and BPH together, or for ED after starting at 2.5 mg.

Can tadalafil 5 mg be taken as needed instead?

The label's as-needed range for ED is 5 to 20 mg before sexual activity, so 5 mg is the low end of that range. Which schedule suits a man is a prescriber's decision.

How long does it take for daily tadalafil to reach steady levels?

The label says steady-state blood levels are reached within 5 days of once-a-day dosing, at about 1.6 times the exposure of a single dose.

Does tadalafil 5 mg have to be taken with food?

No. The Cialis label says it can be taken with or without food and that food does not change absorption.

What are the most common side effects of 5 mg?

In the label trials, the most frequent were headache, indigestion, back pain, stuffy nose and cold-like symptoms. Back pain and muscle aches usually clear within 48 hours.

Further reading

Part of our guide: How ED Medications Work: Timing, Food, Interactions and Combinations

• Sildenafil Headache: How Common Is It?
• Tadalafil With Alcohol: How Much Is Too Much?
• What Is Tadalafil Used For? The Three Approved Uses
• Tadalafil Brand Names: Which Brand Is Used for What