Tadalafil Dosage: A Practical Guide to Getting It Right
If you have just been prescribed tadalafil, or your doctor is discussing dosage options with you, it can be useful to understand how the different strengths and schedules fit together before your appointment. Tadalafil dosing is not one-size-fits-all: it depends on which condition is being treated, whether you and your doctor choose an as-needed or daily approach, and factors like kidney or liver function. This guide walks through the FDA-approved dosing framework in plain language. For the specific question of how much is safe to take in a single 24-hour period, see our companion guide on the maximum dose of tadalafil in 24 hours.
- As-needed (ED): 10 mg starting dose, range 5 to 20 mg
- Daily (ED/BPH): 2.5 mg starting dose, may increase to 5 mg
- PAH (different product): 40 mg once daily, not an ED dose
- Kidney/liver conditions: may require a lower dose or longer interval
Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor sold under the brand name Cialis for erectile dysfunction (ED) and benign prostatic hyperplasia (BPH), and under the brand names Adcirca and Tadliq for pulmonary arterial hypertension (PAH), a separate indication with its own dosing. [Source: Cialis and Adcirca FDA Prescribing Information]
Tadalafil Dosage at a Glance
| Indication | Starting Dose | Typical/Max Dose | Schedule |
|---|---|---|---|
| ED, as-needed | 10 mg | Up to 20 mg | Before activity |
| ED, daily | 2.5 mg | Up to 5 mg | Once daily |
| BPH (± ED) | 5 mg | 5 mg | Once daily |
| PAH (different brand) | 40 mg | 40 mg | Once daily |
[Source: Cialis and Adcirca FDA Prescribing Information] This table reflects standard-indication dosing. Your prescriber may choose a different starting point or schedule based on your health history.
Tadalafil Dosage for Erectile Dysfunction
As-needed dosing
The recommended starting dose for as-needed use is 10 mg, taken before anticipated sexual activity, without regard to food. [Source: Cialis FDA Prescribing Information, Section 2.1] Depending on individual response and tolerability, the dose may be increased to 20 mg or decreased to 5 mg. [Source: Cialis FDA Prescribing Information, Section 2.1] The maximum recommended dosing frequency is once per day for most patients.
Daily dosing
The recommended starting dose for once-daily use is 2.5 mg, taken at approximately the same time each day regardless of when sexual activity occurs. [Source: Cialis FDA Prescribing Information, Section 2.2] Based on efficacy and tolerability, this may be increased to 5 mg once daily. [Source: Cialis FDA Prescribing Information, Section 2.2]
Tadalafil Dosage for BPH
For BPH, whether alone or combined with ED, the recommended dose is 5 mg once daily, taken at approximately the same time each day. [Source: Cialis FDA Prescribing Information, Section 2.3] When tadalafil therapy for BPH is initiated together with finasteride, the same 5 mg once-daily dose is used, typically for up to 26 weeks per the studied regimen. [Source: Cialis FDA Prescribing Information, Section 2.3]
Tadalafil 40 mg: Why This Dose Is Different
Some people searching for tadalafil dosage information come across a 40 mg figure and wonder if it applies to ED. It does not. The 40 mg dose (typically given as two 20 mg tablets) is specific to pulmonary arterial hypertension and is prescribed under the brand names Adcirca or Tadliq, a distinct product and treatment plan from ED/BPH dosing. [Source: Adcirca FDA Prescribing Information] There is no FDA-approved 40 mg dose for ED, and self-adjusting an ED prescription toward that dose is off-label and not supported by the ED/BPH prescribing data.
How to Take Tadalafil
- Swallow the tablet whole; do not split, crush, or chew it. [Source: Cialis FDA Prescribing Information]
- Tadalafil may be taken with or without food; absorption is not meaningfully affected by meals. [Source: Cialis FDA Prescribing Information, Section 12.3]
- For daily dosing, taking it at the same time each day helps maintain a steady level in the body.
- For as-needed dosing, timing relative to sexual activity should follow your prescriber’s specific instructions.
Who Should Not Take Tadalafil
Talk to your doctor before taking tadalafil if any of the following apply to you:
- You take any form of organic nitrate, regularly or intermittently (including nitroglycerin), due to the risk of severe, potentially life-threatening drops in blood pressure. [Source: Cialis FDA Prescribing Information, Section 4.1]
- You have been advised by a doctor to avoid sexual activity due to cardiovascular risk.
- You have a history of vision loss related to non-arteritic anterior ischemic optic neuropathy (NAION).
- You have significant hepatic or renal impairment (see dosage adjustments below). [Source: Cialis FDA Prescribing Information, Section 8.6 to 8.7]
- You take certain alpha-blockers; combined use requires dose spacing and monitoring due to additive blood-pressure-lowering effects. [Source: Cialis FDA Prescribing Information, Section 7.1]
This is not a complete list. Share your full medical history and current medications with your prescriber before starting tadalafil.
Tadalafil Dosage Adjustments
Kidney (renal) impairment
- Creatinine clearance 30 to 50 mL/min: a starting dose of 5 mg once daily is recommended, with a maximum of 10 mg no more than once every 48 hours. [Source: Cialis FDA Prescribing Information, Section 2.4]
- Creatinine clearance below 30 mL/min, or patients on hemodialysis: the maximum dose is 5 mg no more than once every 72 hours. [Source: Cialis FDA Prescribing Information, Section 2.4]
- Daily dosing is generally not recommended in these groups without specific prescriber guidance. [Source: Cialis FDA Prescribing Information, Section 8.6]
Liver (hepatic) impairment
Dosing in mild to moderate hepatic impairment should not exceed 10 mg, and daily dosing is not recommended. Tadalafil has not been studied in severe hepatic impairment and should be used with caution if prescribed at all. [Source: Cialis FDA Prescribing Information, Section 8.7]
Drug interactions that affect dosing
Strong CYP3A4 inhibitors (such as ketoconazole or ritonavir) can significantly increase tadalafil levels in the body, which may require a lower dose or longer interval between doses. [Source: Cialis FDA Prescribing Information, Section 7.2] Always give your prescriber a complete list of medications, including over-the-counter drugs and supplements.
What to Do If You Miss a Dose
For daily dosing, if you miss your usual time, take the next dose at your regular scheduled time rather than doubling up; do not take two doses to make up for a missed one. For as-needed dosing, there is no “missed dose” in the traditional sense since it is taken only before anticipated activity; simply take the next dose as directed when needed. If you are ever unsure, contact your prescriber or pharmacist rather than guessing.
Generic Tadalafil Dosage vs Brand-Name Cialis
FDA-approved generic tadalafil is held to the same bioequivalence and manufacturing standards as brand-name Cialis, and dosing recommendations are the same across both. [Source: FDA generic drug approval standards] Strength, schedule, and adjustment guidance in this article apply equally to generic and brand-name products prescribed by a licensed provider.
When to See a Doctor
Contact your prescriber if your current dose does not seem to be working, if you are experiencing side effects that feel severe or do not improve, if your kidney or liver function changes, or if you are prescribed a new medication that might interact with tadalafil. Seek immediate medical care for an erection lasting more than 4 hours, sudden vision or hearing changes, chest pain, or symptoms of a severe allergic reaction. [Source: Cialis FDA Prescribing Information, Sections 5.2 to 5.4]
Frequently Asked Questions
What is the standard dosage of tadalafil?
How do I know what tadalafil dosage I need?
Can tadalafil dosage be split in half?
What is the tadalafil dosage for BPH?
Is 40 mg of tadalafil ever prescribed for ED?
Can I take tadalafil with nitrate medications?
A Word on Unverified or Counterfeit Tadalafil
Tadalafil should only be obtained through a licensed prescriber and pharmacy. Products marketed as “natural tadalafil” or herbal alternatives are not FDA-regulated for safety or effectiveness, and counterfeit tadalafil sold outside licensed channels may contain incorrect, contaminated, or undisclosed ingredients. [Source: FDA Consumer Updates, “Is It Really ‘FDA Approved’?”] If a dose, source, or product feels uncertain, confirm with a pharmacist or prescriber before taking it.
Sources: Cialis (tadalafil) Full Prescribing Information, FDA (accessdata.fda.gov). Adcirca (tadalafil) Prescribing Information, FDA (accessdata.fda.gov). FDA Consumer Updates, “Is It Really ‘FDA Approved’?”