Maximum Dose of Tadalafil in 24 Hours: What the Label Says

By the ShopMedRx team

For erectile dysfunction (ED), the maximum dose of tadalafil in 24 hours is 20 mg, taken no more than once per day, when the medicine is used as needed before sexual activity.^[1] When a clinician prescribes tadalafil for daily use instead, the labeled ceiling is 5 mg once a day.^[2] These are limits from the FDA label for tadalafil tablets, and many people need a lower ceiling because of other medicines or health conditions.

This guide goes deeper than a simple chart. It explains how the two dosing schedules differ, why "per 24 hours" matters for a long-acting medicine, where numbers like 40 mg and 8.5 mg come from, and what to ask a licensed clinician. Tadalafil is prescription-only, and a clinician decides whether it is appropriate for you and at what dose. If you want the bigger picture on how it compares with other options, see our post on sildenafil vs tadalafil.

What is the maximum dose of tadalafil in 24 hours?

The answer depends on how the medicine is prescribed. The FDA label for tadalafil tablets describes two schedules for ED, and each has its own ceiling.

• As-needed use: the usual starting dose is 10 mg before anticipated sexual activity. A clinician may raise it to 20 mg or lower it to 5 mg. The label says the maximum recommended frequency is once per day in most patients.^[1]
• Once-daily use: the usual starting dose is 2.5 mg at about the same time each day, with or without regard to sexual activity. It may be increased to 5 mg based on how well it works and how well it is tolerated.^[2]

So the maximum dose of tadalafil for erectile dysfunction is 20 mg in a day on the as-needed schedule and 5 mg in a day on the daily schedule. These are not meant to be stacked. A clinician chooses one schedule for you, and taking an extra tablet of either type on top of it is not something the label supports.

Tadalafil dosage chart for ED, BPH and PAH

Tadalafil is also labeled for other conditions, which is one reason online dose numbers look confusing. This tadalafil dosage chart separates them. Tablets come in 2.5 mg, 5 mg, 10 mg and 20 mg strengths.^[2]

Use	Usual starting dose	Labeled ceiling
ED, as needed	10 mg before sexual activity	20 mg, no more than once per day[1]
ED, once daily	2.5 mg at about the same time daily	5 mg once daily[2]
Benign prostatic hyperplasia (BPH), once daily	5 mg	5 mg once daily[2]
ED and BPH together, once daily	5 mg	5 mg once daily[2]
Pulmonary arterial hypertension (PAH)	40 mg once daily	Not an ED dose; doses above 40 mg have not been studied in PAH[3]

The chart shows the usual label numbers. Your own dose is set by a clinician who knows your health history and your medicine list.

Tadalafil 20 mg dosage: the as-needed ceiling

The tadalafil 20mg dosage is the top of the as-needed range. It is not a starting point. The label starts most patients at 10 mg and moves up to 20 mg only if the lower dose is not enough and side effects are acceptable.^[1]

In studies described in the label, erectile function improved compared with placebo for up to 36 hours after a dose.^[1] Individual results vary. The label limits as-needed use to once per day, and a second dose "just in case" later the same day is not something the label recommends.^[1]

Tadalafil dosage daily: what the daily dose of tadalafil looks like

A daily dose of tadalafil is much lower than an as-needed dose. The label starts once-daily use at 2.5 mg and allows an increase to 5 mg.^[2] The schedule is taken at about the same time each day.

It helps to know how long the medicine stays in the body. The mean terminal half-life of tadalafil is 17.5 hours in healthy subjects, and steady levels build up within about 5 days of once-daily dosing.^[5] One review reports a longer half-life, about 21.6 hours, in elderly men.^[6] In plain words, some of yesterday's dose is still in your system today, which is one reason to follow the prescribed schedule exactly.

Daily or as needed: how a clinician may think about it

Both schedules are options for ED. A clinician may weigh how often you expect to need it, other medicines you take, kidney and liver health, and how you tolerated earlier doses. Neither schedule is better for everyone, so this is a conversation to have rather than a choice to make alone.

Tadalafil dosage 40 mg and tadalafil 8.5mg: where these numbers come from

Many people search for tadalafil dosage 40 mg. The 40 mg dose is real, but it belongs to a different condition. The FDA label for tadalafil used to treat pulmonary arterial hypertension recommends 40 mg (two 20 mg tablets) once daily, and it advises against splitting that dose across the day.^[3] That is not an ED dose. For ED, 40 mg in 24 hours is double the 20 mg ceiling on the as-needed schedule and eight times the 5 mg ceiling on the daily schedule.

The same label notes that doses greater than 40 mg have not been studied in PAH.^[3] Separately, the overdose section of the tadalafil label says single doses up to 500 mg were given to healthy subjects and multiple daily doses up to 100 mg to patients, with adverse events similar to those at lower doses.^[5] That is safety data from studies, not a recommendation, and it does not mean higher doses are safe for you.

You may also see tadalafil 8.5mg online. That number is not one of the tablet strengths listed on the FDA label for tadalafil tablets (2.5, 5, 10 and 20 mg).^[2] Because the label does not describe an 8.5 mg dose, this article cannot give a limit for it. Do not cut tablets or combine products to reach a number you read online. If a prescription lists a strength you do not recognize, ask your clinician or pharmacist how it should be taken and what your 24-hour limit is.

When the 24-hour limit is lower than 20 mg

The ceilings above are for most adults. The label lowers them in several situations, and this is exactly why a clinician reviews your history first.

Situation	What the label says
Taking a strong CYP3A4 inhibitor (for example ritonavir, ketoconazole or itraconazole)	As-needed dose limited to 10 mg no more than once every 72 hours; once-daily dose not to exceed 2.5 mg[1]
Moderate kidney impairment (creatinine clearance 30 to 50 mL/min)	Start at 5 mg no more than once per day; maximum 10 mg no more than once every 48 hours[1]
Severe kidney impairment or hemodialysis	As-needed dose limited to 5 mg no more than once every 72 hours; once-daily use is not recommended[1],[4]
Mild or moderate liver impairment	As-needed dose should not exceed 10 mg once per day[4]
Severe liver impairment	Use is not recommended[1]

The label also says drugs that induce CYP3A4, such as rifampin, can lower tadalafil exposure.^[1] If you take any prescription, over-the-counter or herbal products, bring the full list to your clinician.

Safety: who should not take tadalafil and what to watch for

Tadalafil is not right for everyone. Key points from the label and from MedlinePlus:

• Never with nitrates or riociguat. Tadalafil taken with nitrates can drop blood pressure to an unsafe level, with dizziness, fainting, heart attack or stroke possible.^[2],[7] Nitrates come as tablets, under-the-tongue tablets, sprays, patches and ointments, and MedlinePlus also lists nitrate-containing "poppers."^[7]
• Blood pressure medicines and alcohol. The label says tadalafil can add to the blood-pressure-lowering effects of nitrates, alpha-blockers, antihypertensives and alcohol.^[8] Drinking 5 units or more of alcohol with tadalafil can raise the chance of dizziness and a fast heart rate.^[4]
• Erection lasting longer than 4 hours. MedlinePlus lists this as a reason to call your doctor or get emergency care right away.^[7] The label advises caution in people with conditions that can raise priapism risk, such as sickle cell anemia, multiple myeloma or leukemia, or with a penile shape problem such as Peyronie's disease.^[8]
• Sudden vision loss. The label says to stop PDE5 inhibitors, including tadalafil, and seek medical attention if vision is suddenly lost in one or both eyes, which may signal a rare condition called NAION.^[8]
• Sudden hearing loss. Stop and seek prompt medical attention if hearing suddenly drops or ringing and dizziness appear.^[8]

If you have heart disease, low blood pressure, an eye condition such as retinitis pigmentosa, or you have ever had sudden severe vision loss, tell the clinician before any dose is considered.^[7]

What if you take more than prescribed or miss a dose?

If you took more than your prescription says, do not take another dose to "even it out." Contact your clinician or a poison control center, and call emergency services if you have chest pain, fainting, a painful erection lasting more than 4 hours, or sudden vision or hearing changes.

If you miss a dose on a daily schedule, ask your clinician or pharmacist what to do rather than doubling up. Doubling can push you past the labeled limit.

A note on compounded tadalafil

The dosing numbers above come from FDA labels for tadalafil tablets. Compounded medications, including any compounded tadalafil product a clinician may prescribe through ShopMedRx, are different. Compounded drugs are not FDA-approved, and the FDA does not review their safety, effectiveness or quality before they are marketed.^[9] The FDA also notes that labels on compounded drugs may not include adequate directions for safe use.^[10]

That is a good reason to follow your prescription and pharmacy directions exactly and to ask questions about anything that is unclear. Your prescribing clinician decides the dose; this article cannot.

Questions to ask a clinician about your dose

1. Is an as-needed or a daily schedule more appropriate for me, and why?
2. What is my maximum dose in 24 hours, and how many hours should pass before another dose?
3. Do any of my current medicines, including nitrates, blood pressure medicines, HIV or antifungal drugs, change my limit?
4. Do my kidney or liver tests change the dose?
5. What side effects mean I should stop and get care right away?
6. How should I handle alcohol while taking this medicine?

Frequently asked questions

What is the maximum dose of tadalafil in 24 hours?

For ED on an as-needed schedule, the FDA label allows up to 20 mg, no more than once per day. On a once-daily schedule, the ceiling is 5 mg per day.^[1],[2] Some people have lower limits, so follow your own prescription.

Can I take tadalafil 40 mg for ED?

No. The 40 mg dose is labeled for pulmonary arterial hypertension, not ED.^[3] For ED, 40 mg in a day is above the labeled maximum, so do not take it unless your clinician has told you otherwise for a medical reason.

Is 5 mg of tadalafil a daily dose or an as-needed dose?

Both. Five mg is the top of the once-daily range and the low end of the as-needed range.^[1],[2] Your prescription will say which schedule applies to you.

How long does one dose of tadalafil last?

The label says erectile function improved compared with placebo for up to 36 hours after a dose in studies, and the half-life is 17.5 hours in healthy subjects.^[1],[5] Individual results vary.

Can I take tadalafil with alcohol?

The label warns that alcohol can add to the blood-pressure-lowering effect of tadalafil, and that drinking 5 units or more can increase dizziness and heart rate changes.^[8],[4] Ask your clinician what is safe for you.

What dose is tadalafil 8.5mg equal to?

The FDA label for tadalafil tablets lists strengths of 2.5, 5, 10 and 20 mg, so 8.5 mg is not one of the labeled tablet strengths.^[2] This article cannot say what 8.5 mg means for you. Ask your clinician or pharmacist how any strength on your prescription should be taken and what your daily limit is.

Talk to a licensed clinician

Tadalafil is a prescription medicine for adults 18 and older. At ShopMedRx, you complete an online health assessment, and an independent, licensed clinician reviews it and decides whether a prescription is appropriate. There is no guarantee of a prescription. If one is written, it is filled by a licensed U.S. partner pharmacy. You can read about the Powered Up Pill: tadalafil program or compare formats in our guide to ED medicine formats.

Check if you qualify

This article is for education and is not medical advice. Talk to a licensed clinician before you start, stop or change any medicine.

Important information

• This article is for general education and is not medical advice. Talk to a licensed clinician before starting, stopping or changing any treatment.
• All medications available through ShopMedRx are prescription only and are prescribed only if appropriate after a licensed clinician's review.
• Some medications we offer are compounded. Compounded medications are not FDA-approved, and the FDA does not review compounded drugs for safety, effectiveness or quality before they are marketed. They are not the same as, or generic versions of, brand-name drugs.
• Individual results vary. Nothing in this article promises a specific result.
• Prescriptions are written by independent, licensed clinicians through OpenLoop Health and filled by licensed U.S. partner pharmacies.

Sources

1. U.S. Food and Drug Administration / National Library of Medicine. Tadalafil tablets (as-needed and once-daily use): drug label information. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7e4cdac1-42cc-4038-a86b-4890962ed806
2. Tadalafil tablets: package insert / prescribing information (once-daily dosing, strengths, patient information). Drugs.com, label text. https://www.drugs.com/pro/tadalafil.html
3. Tadalafil tablets for pulmonary arterial hypertension: drug label information. DailyMed, U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=efa03afa-c412-4b31-bf26-7c3a6f7311af
4. Tadalafil tablets, coated: drug label information (hepatic impairment, alcohol, renal dosing). DailyMed, U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=abcb2cda-9b3f-45f6-ad5f-c2370b0dd114
5. Tadalafil tablets: prescribing information (pharmacokinetics and overdosage). U.S. FDA, 2018. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/021368s030lbl.pdf
6. Tadalafil in the treatment of erectile dysfunction. PubMed Central, National Library of Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC2643112/
7. Tadalafil: MedlinePlus drug information. National Library of Medicine. https://medlineplus.gov/druginfo/meds/a604008.html
8. Tadalafil tablet: drug label information (warnings on priapism, eye and hearing effects, blood pressure interactions). DailyMed, U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=2a4666e1-4151-f540-e063-6394a90aed0b
9. U.S. Food and Drug Administration. Human Drug Compounding. https://www.fda.gov/drugs/guidance-compliance-regulatory-information/human-drug-compounding
10. U.S. Food and Drug Administration. Understanding the Risks of Compounded Drugs. https://www.fda.gov/drugs/human-drug-compounding/understanding-risks-compounded-drugs