Cialis is a brand-name prescription medication that contains the active drug tadalafil. It belongs to the drug class called phosphodiesterase 5 (PDE5) inhibitors. Cialis is available in a generic form.
This medication has been approved by the Food and Drug Administration (FDA) to treat the following in adult males:*
- erectile dysfunction (ED)
- benign prostatic hyperplasia (BPH)
- both ED and BPH
* Sex and gender exist on spectrums. In this article, use of the term “male” refers to sex assigned at birth.
Cialis is available as follows.
- Form: oral tablet
- Strengths: 2.5 milligrams (mg), 5 mg, 10 mg, and 20 mg
In this article, you’ll find additional information about Cialis’s dosage and details on how to take the drug. For a comprehensive overview of Cialis, view this article.
Dosage summary
For details about the drug’s dosage, see the “Cialis: Dosage” section below. Your doctor will prescribe the dosage of Cialis that’s right for your condition.
Finding a healthcare professional
If you’re interested in taking Cialis, search here to find a doctor who might prescribe it.
This article describes typical recommended dosages for Cialis. These dosages are provided by the drug’s manufacturer.
Always follow the dosage of Cialis that your doctor prescribes.
Commonly recommended dosages for Cialis are shown below.
You should take the dosage your doctor prescribes for you. They’ll recommend the dosage that’s best for your condition.
Cialis’s form and strengths
Cialis comes as a tablet that you take by mouth.
Cialis tablets are available in the following strengths:
- 2.5 milligrams (mg)
- 5 mg
- 10 mg
- 20 mg
Typical recommended dosages
Usually, doctors will prescribe a recommended dosage of Cialis at the start of treatment. Then, they’ll adjust the dosage over time if needed. In some cases, your maintenance dosage may be lower than your starting dosage. Ultimately, your doctor will prescribe the smallest dosage of Cialis that gives the desired effect.
Cialis may be taken daily or as needed. For example, if you’re taking the drug to treat erectile dysfunction (ED), your doctor may have you take it as needed. Or they may prescribe a daily dosage of Cialis for ED. When used for benign prostate hyperplasia (BPH), Cialis is typically taken daily. However, be sure to take this medication exactly as your doctor prescribes it.
The dosage chart below summarizes recommended dosages for Cialis in adult males.*
| Starting dosage | Maintenance dosage | Maximum dosage | |
| Dosage for ED | • as needed dosage: 10 mg at least 30 minutes before sexual activity, with a maximum of one dose per day† • daily dosage: 2.5 mg once daily |
• as needed dosage: 5 mg to 20 mg at least 30 minutes before sexual activity, with a maximum of one dose per day† • daily dosage: 2.5 mg to 5 mg once daily |
• as needed dosage: 20 mg once daily at least 30 minutes before sexual activity, with a maximum of one dose per day† • daily dosage: 5 mg once daily |
| Dosage for BPH | 5 mg once daily | 5 mg once daily | 5 mg once daily |
| Dosage for both ED and BPH | 5 mg once daily | 5 mg once daily | 5 mg once daily |
* Sex and gender exist on spectrums. In this article, use of the term “male” refers to sex assigned at birth.
† Cialis may keep working to treat ED for up to 36 hours after taking a dose. For this reason, you may not need to take this medication every day when using it as needed. Your doctor can recommend a Cialis dosing frequency that is best for you.
Length of treatment
Doctors typically prescribe Cialis as a long-term treatment. You’ll likely take it long term if you and your doctor feel it is safe and effective for your condition.
However, if you take Cialis with finasteride (Proscar) to treat symptoms of BPH, you’ll likely take Cialis for up to 26 weeks. After that, you’ll stop taking Cialis and continue taking finasteride alone. To learn more about taking Cialis with finasteride, see this article.
Below are some common questions related to Cialis’s dosage.
Do doctors prescribe Cialis in 40-mg or 80-mg doses?
Not typically. The maximum recommended dosage of Cialis is 20 milligrams (mg) once daily if you take it as needed to treat erectile dysfunction (ED). For all other Cialis-approved uses, the recommended maximum dosage is 5 mg once daily.
It’s important that you take Cialis exactly as your doctor prescribes it. Taking more Cialis than prescribed can increase your risk of serious side effects.
Talk with your doctor if you have questions about your Cialis dosage.
What’s the dosage of Cialis for occasional use?
Cialis may be used as needed to treat ED. For this use, doses range from 5 milligrams (mg) to 20 mg as needed before sexual activity.
Cialis may keep working for up to 36 hours after taking a dose. For this reason, you may not need to take this medication every day when using it for occasional use.
For more detailed information about Cialis dosage for treating ED, see the “Cialis: Dosage” section above.
Is there a ‘low dose’ of Cialis?
The lowest recommended starting dosage for Cialis is 2.5 milligrams (mg) once daily. Doctors may prescribe this dosage to treat ED. In this case, you would take this dosage every day even if you don’t have sex.
See the “Cialis: Dosage” section above or talk with your doctor for more detailed information about Cialis dosage.
What’s considered a ‘normal dose’ of Cialis?
A usual dose of Cialis can depend on several factors, including the condition you’re using Cialis to treat and other medical conditions you may have.
Your doctor will prescribe the dosage that best fits your needs. The recommended Cialis dosage can range from 2.5 milligrams (mg) to 20 mg per day. For details about Cialis dosage, see the “Cialis: Dosage” section above.
Talk with your doctor if you have questions about your Cialis dosage.
Your doctor will consider several factors when prescribing the dosage for Cialis. These factors include:
- the condition you’re taking Cialis to treat
- the severity of your condition
- other medications you take
Your prescribed dosage may also vary based on other medical conditions you have, including kidney or liver problems.
Recommended adjustments in dosage
It is important to tell your doctor all the medications you take and any other conditions you have before you start taking Cialis.
Cialis is broken down in your liver by the enzyme (a type of protein) CYP3A4.
Certain medications inhibit (slow down) the action of CYP3A4. If you take Cialis with these medications, your body could metabolize Cialis differently than usual.
Examples of these medication may include ritonavir (Norvir, Paxlovid) and ketoconazole oral tablet. Taking Cialis with these medications can increase your risk of side effects from Cialis. If you’re taking these types of drugs with Cialis, your doctor may decrease your Cialis dosage.
Your doctor may also decrease your dosage if you have certain kidney or liver problems, such as chronic kidney disease or liver failure.
Talk with your doctor about your health history before starting Cialis. They’ll decide whether Cialis is safe for you to take and prescribe the dosage that is best for you.
Cialis comes as an oral tablet. You will take it by mouth. Cialis tablets are meant to be swallowed whole. You can take it with or without food.
If you’re taking Cialis to treat erectile dysfunction (ED), your doctor may prescribe this medication for use as needed. In this case, you’ll typically take Cialis at least 30 minutes before sexual activity. However, do not take more than one dose of Cialis per day. Cialis may keep working for up to 36 hours after you take your dose. For this reason, you may not need to take Cialis every day.
Your doctor may also prescribe a lower dosage of Cialis for ED to take once daily. If your doctor prescribes this dosage, you’ll take Cialis every day, regardless of sexual activity.
If you’re taking Cialis to treat symptoms of benign prostate hyperplasia (BPH) or for both ED and BPH, you’ll take Cialis once daily.
If you are taking Cialis daily, your doctor may recommend that you take the drug around the same time of day. Doing so will help maintain a consistent amount of the drug in your body. And this can help Cialis work effectively.
If it’s difficult for you to swallow tablets, see this article for information on taking this form of medication. Talk with your doctor or pharmacist and ask if they have other suggestions to help you take the medication.
If you find it challenging to read the label on your prescription, tell your doctor or pharmacist. Certain pharmacies provide medication labels with large print or braille. They may also offer labels containing a scannable code that your smartphone can convert from text to speech. If your pharmacy doesn’t provide these choices, your doctor or pharmacist may be able to recommend a pharmacy that does.
If it’s difficult for you to open medication bottles, ask your pharmacist if they can dispense Cialis in an easy-open container. They also may recommend ways to help make it easier to open the bottles.
If you miss a dose of Cialis, take it as soon as you remember on the same day. Do not take more than one Cialis dose per day.
View these medication reminder options to help avoid missing doses. You could also set an alarm or download a reminder app on your phone.
For some drugs, taking more than the recommended dosage may lead to unwanted side effects or overdose. Do not take more Cialis than your doctor prescribes.
What to do if you take too much Cialis
Call your doctor if you think you’ve taken too much of this drug. Also, you can call the American Association of Poison Control Centers at 800-222-1222 or use its online tool. However, if your symptoms are severe, call 911 or your local emergency number. Or go to the nearest emergency room right away.
Talk with your doctor or pharmacist for additional information about Cialis’s dosage. Keep in mind that the dosages presented in this article are typical dosages provided by the drug’s manufacturer. Your doctor will recommend the dosage of Cialis that’s right for you and your condition. Always follow the dosage that your doctor prescribes for you.
As with any medications you’re taking, do not change your Cialis dosage without a recommendation from your doctor.
In addition to discussing Cialis with your doctor, you may find the following articles helpful in learning more:
- Overview of Cialis. For comprehensive details on Cialis, see this article.
- Drug comparisons. To learn how Cialis compares with Viagra, read this article.
- Information on side effects. If you’d like to know about possible side effects of Cialis, view this article.
- Details about Cialis’s uses. To learn more about the conditions Cialis is used to treat, see these articles about erectile dysfunction (ED) and benign prostate hyperplasia (BPH).
Disclaimer: Healthgrades has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.