How to Get Maximum Effect From Cialis (Tadalafil)

Cialis is a prescription drug that contains the active ingredient tadalafil .

The Food and Drug Administration (FDA) approved its use in people assigned male at birth to treat:

This article will help the reader understand how to take Cialis for ED and outline other important information about this medicine.

How to Get Maximum Effect From Cialis (Tadalafil)

Cialis contains the ingredient tadalafil, also available as a generic medication. As with any prescription medication, you should follow the directions carefully.

For erectile dysfunction, Cialis is prescribed for one of the following reasons:

• On an as-needed basis several hours before sexual activity
• As a once-daily medication to allow for spontaneity

Dosing will be discussed further in this article.

Cialis can help symptoms of erectile dysfunction. However, using this medication as part of a comprehensive treatment that may include couples therapy can be more helpful.

Although many people try to address ED with medication, couples may also find therapy to be greatly helpful when managing ED.

The following lifestyle changes can also help with ED:

• Quitting smoking
• Reducing alcohol intake
• Increasing exercise (ask your healthcare provider before beginning a new exercise plan)
• Eating healthier
• Losing weight
• Reducing stress
• Getting enough quality sleep
• Managing other health conditions, such as diabetes or high blood pressure

Lifestyle changes are easier said than done. However, even trying to make a few minor changes over time can help. Ask your healthcare provider for advice. For example, they may refer you to a registered dietitian nutritionist (RDN) to help you with your nutrition, exercise, weight management, and more.

What Should I Avoid While Taking Cialis?

It’s best to avoid the following when using Cialis.

Alcohol

In general, higher alcohol consumption increases the risk of sexual problems. Even those who overindulge in alcohol only on occasion can have temporary ED problems.

In addition, combining Cialis and alcohol can cause severely low blood pressure.

Avoid alcohol or reduce the amount you drink as much as possible.

People who need help with an immediate alcohol crisis can call 988 to get in touch with the 988 Suicide & Crisis Lifeline. The Substance Abuse and Mental Health Services Administration (SAMHSA) hotline at 1-800-662-HELP (4357) offers free and confidential help at any time.

Grapefruit

When you take Cialis, avoid grapefruit and grapefruit juices, including mixed fruit drinks that contain grapefruit.

Grapefruit can slow Cialis’s elimination from the body and can lead to the following:

• Low blood pressure
• Priapism (a medical emergency with a prolonged, painful erection)
• Other side effects

Medication Interactions

Some medications can interact with Cialis.

Before taking Cialis, tell your healthcare provider about all your medicines.

This includes prescription and over-the-counter medicines and vitamins or supplements.

While taking Cialis, do not start any new medications without approval from your healthcare provider.

Some interactions include:

• Nitrates such as nitroglycerin, isosorbide mononitrate, or isosorbide dinitrate (This includes certain recreational drugs such as amyl nitrate, butyl nitrate, or nitrite, known as “poppers.” Using nitrates with Cialis can cause a sudden and dangerous drop in blood pressure. They should never be taken together.)
• Alpha-blockers such as doxazosin, tamsulosin, or alfuzosin
• Certain antibiotics like erythromycin
• Drugs that treat high blood pressure
• Antifungals such as Diflucan (fluconazole)
• Ritonavir
• Rifampin
• Riociguat

This is not a complete list of interactions; others may occur with Cialis.

Consult your healthcare provider for more information about interactions and how they may affect you.

How Does Cialis Work?

Cialis belongs to a drug class called phosphodiesterase type 5 inhibitors, or PDE5 inhibitors.

Medications in this drug class work by affecting an enzyme called phosphodiesterase type 5.

By doing so—combined with sexual stimulation—a cascade of events occurs that increases nitric oxide.

This process helps increase blood flow to the penis and achieve an erection.

How Do I Take Cialis?

Cialis is available as a tablet that’s taken by mouth. Dosages include 2.5 milligrams (mg), 5 mg, 10 mg, and 20 mg.

Cialis can be taken with or without food. The pill should be swallowed whole and not crushed, broken, or chewed.

Cialis alone does not lead to an erection. To work, it requires sexual stimulation as well.

Cialis is approved in adults assigned male at birth; it is not approved for use in children or adolescents.

Dosing is as follows:

• As needed for ED: 5 to 20 mg by mouth as a one-time dose, with a maximum of one dose in 24 hours. Effects may last up to 36 hours.
• Daily dosing for ED: 2.5 or 5 mg by mouth daily. For daily dosing, the maximum dose is 5 mg per day. The medication should be taken once daily at about the same time every day to maintain a consistent level of medicine in the body. It does not have to be taken around the time of sexual activity.
• BPH: 5 mg by mouth daily.

People with kidney or liver problems will need to either take a lower dose of Cialis or avoid the medication altogether, depending on the severity of the condition.

How Quickly Does Cialis Work?

Some studies show that Cialis reaches its maximum effect around two hours after taking an as-needed dose. However, everyone is different, and it may take less time or more time to work for you.

Maximum effects can be seen between 30 minutes and eight hours.

It may take some time and trial and error to determine the best dosage as well as the best time to take Cialis. What does this mean?

• Some may find that Cialis works in two hours and takes the medicine two hours before sexual activity.
• Others may find that it takes Cialis closer to eight hours to work and take the medication well before sexual activity.

Some people opt for a lower daily dose. This ensures the medication is always in the person’s system and allows for spontaneous sexual activity without planning dosing times.

You can talk to your healthcare provider about the best dosage for you.

How Long Does Cialis Usually Last?

A dose of Cialis can remain effective in the body for up to 36 hours. Because it may last this long, Cialis should not be taken more than once daily.

Side Effects

Common side effects of Cialis include the following:

• Headache
• Muscle pain/back pain
• Common cold/runny nose/sinus infection
• Indigestion
• Flushing
• Pain in the extremities
• Diarrhea

Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you have a medical emergency.

Serious side effects and their symptoms can include the following:

• Anaphylaxis (allergic severe reaction): Get emergency medical help if you have urticaria (hives), difficulty breathing, or swelling of the face, lips, tongue, or throat
• Severe skin reactions: Get emergency medical help if you have a fever, burning eyes, sore throat, skin pain, red or purple rash, or blistering/peeling skin.
• Sudden death
• Heart attack
• Stroke
• Chest pain
• Severely low blood pressure
• Vision loss: People who experience sudden vision loss in one or both eye(s) should stop taking Cialis and get medical help immediately.
• Hearing loss: People who experience decreased hearing or hearing loss should stop taking Cialis and get medical help immediately.
• Seizures
• Priapism
• Fainting

Report Side Effects

Cialis may cause other side effects. Call your healthcare provider if you have unusual problems while taking this medication. If you experience a severe side effect, you or your provider may send a report to the FDA’s MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Summary

Cialis (tadalafil) is a prescription medication taken as needed – or once daily – to help with erectile dysfunction (ED) and benign prostatic hyperplasia (BPH).

It works in combination with sexual stimulation.

ED may also involve other issues, so lifestyle changes and addressing underlying issues may help improve ED symptoms.

People may have different experiences with how long Cialis takes to work. It may take some trial and error before finding the best dose for you and the time to take it.

Talk with your healthcare provider for more information and medical advice on how to benefit from Cialis.

Frequently Asked Questions

Cialis is a PDE5 inhibitor. It is similar to drugs like Viagra (sildenafil), Levitra (vardenafil), and Stendra (avanafil).

Adcirca and Revatio also contain the active ingredient tadalafil. However, these medications are FDA-approved to treat pulmonary arterial hypertension (high pressure in the lungs’ blood vessels).

Can I take a second Cialis pill if the first one does not work right away?

A Cialis tablet can take up to several hours to start working. Remember that it will not cause an erection on its own. Sexual stimulation must occur. If one Cialis is not working, talk to your healthcare provider. Because one Cialis pill stays active in the body for 36 hours, the prescribing information states that Cialis should not be taken more than once daily.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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By Karen Berger, PharmD
Karen Berger, PharmD, is a community pharmacist and medical writer/reviewer.

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