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How Long Does Cialis® (Tadalafil) Last?

Kelly Brown MD, MBA

Reviewed by Kelly Brown MD, MBA

Written by Geoffrey Whittaker

Published 02/10/2021

Updated 07/14/2023

If you’ve been reading up on treatment options for erectile dysfunction (ED), you’ve probably come across brands like Cialis® and Viagra®. If so, we’re guessing you have questions about what makes these medications different. 

Many things separate Cialis (and its generic version, tadalafil) from Viagra (also known as sildenafil). But the most significant difference we can point to is how long each medication lasts. 

Viagra is typically taken for a certain amount of time before you get down to business in the bedroom. Cialis can actually be taken that way as well, or it can be taken as a daily medication.

How you take it, when you take it and how much of it you take are all solid follow-up questions we promise to answer below. We’ll also share some good-to-know facts about Cialis — if you’re new to this medication, you’ll want to start there.

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We’re going to dig into the complicated medical science in a moment, but first, we need to address how Cialis works.

Cialis is a brand-name version of the medication tadalafil. The active ingredient is a prescription treatment for ED, as well as benign prostatic hyperplasia or enlarged prostate.

 Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor — a medication that works by supporting better dilation of your blood vessels (including the ones in your boner) and a subsequent increase of blood flow to the soft tissue of your penis. Once you’re aroused, blood flow leads to erections — problem solved.

Cialis has proven to be a pretty effective treatment for ED — a fairly common condition affecting an estimated 30 million to 50 million men nationwide. 

Part of the reason it works so well is that there are two effective treatment options for tadalafil: an as-needed dose and a smaller daily Cialis option that can be taken, well…daily.

Fun fact: Tadalafil is actually the first ED medication ever approved for daily use.

Not so fun fact: Tadalafil is not a cure for ED — there is no ED cure, partly because many factors can cause erectile dysfunction, including:

  • Heart disease

  • Diabetes

  • High cholesterol

  • High blood pressure

  • Obesity

  • Depression

  • Anxiety

  • Illicit drug use

  • Excessive alcohol use

  • Performance anxiety

This medication merely treats the ED symptom by increasing the dilation of blood vessels. 

By the way, PDE5 inhibitors have other uses — medications like tadalafil can also be used to treat certain types of hypertension. 

A quick note: There are some common side effects of Cialis you should be aware of. This includes headaches, fatigue, back pain, nasal congestion, flushing, and pain in the limbs and muscles.

Like other ED treatments, tadalafil works primarily by affecting blood flow, which means misuse or an overdose of this medication could lead to low blood pressure.  

If you have chest pain, back pain or feel like you might be experiencing a heart attack, seek medical attention immediately.

We’d like to give you a short answer to this seemingly simple question, but we can’t yet. How long tadalafil lasts is a hard question to answer, as it depends on two factors: dosage and usage.

Generally, tadalafil differs from other FDA-approved PDE5 inhibitors offered at pharmacies in that it has a significantly larger time frame of efficacy. Unlike Viagra, for instance, which can work for a few hours after the medication is taken, just a single dose of tadalafil can be effective for up to 36 hours.

According to FDA recommendations, Cialis should be used either: 

  • Once daily at a dose between 2.5 and 5-mg tablets

  • As needed at a dose between 5 and 20-mg tablets

In both cases, it’s possible Cialis will last for up to 36 hours. But you should never take Cialis more than once daily, as it may last the full 36 hours.

That’s not to say you’ll be erect for 36 hours. First, that would be very dangerous for your penis, and second, it would have probably stopped being fun somewhere around the 32-hour mark.

Many men might argue there’s no such thing as a “too long” erection. But these guys haven’t heeded the warnings of erections lasting more than four hours — a condition called priapism.

Priapism is arare side effect of ED drugs that results in prolonged erections, which can damage blood vessels and potentially permanently damage your member. Erections lasting more than four hours sound kind of painful — if you have one, seek emergency medical attention.

You may be wondering, Does tadalafil stay in your system for 36 hours? It certainly can, depending on what tadalafil dosage you’re prescribed.

The mean terminal half-life of tadalafil (an official-sounding term for how long it takes your body to process enough of the medication out of your bloodstream to reduce its concentration to half) is 17.5 hours, according to the FDA. This is a little less than half of that 36-hour number we mentioned earlier.

According to the FDA, the medication will reach maximum concentration in your bloodstream somewhere between 30 minutes and six hours after you take it. 

At 17 and a half hours, you’ll have about half the concentration of medication in your bloodstream, and it’ll continue to fall until it’s all gone. If it’s a low-dose volume, the effects will weaken more rapidly.

Some reports have suggested that Cialis can occasionally be effective for longer, including reports of up to 72 hours of effectiveness. But generally, most people will experience 24 to 36 hours of effects from a dose calibrated properly to their needs.

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As mentioned above, different Cialis dosages will affect the practical duration of the medication’s effects. As a daily dose continues to replenish itself every day when you take it, your duration will essentially last as many days as you take the medication in a row. 

This means that at a daily, lower dose, you never go long enough between doses to let the medication fully leave your body. In other words, the concentration should remain high enough to experience a normal frequency of erections every day.

Larger doses, like Cialis 20mg tablets, might stay active longer. However, it’s hard for us to tell you when the medication will punch out for the day because the actual effective hours will vary based on your individual response to the medication.

A word to the wise, guys: If you’re wondering how to get the maximum effect from Cialis, the answer is not double doses, frequent doses or taking this medication in any way not specifically instructed by a healthcare professional. The result could be common or serious side effects, many of which are common among all PDE5 inhibitors.

Generally speaking, you should avoid taking any of these medications with nitrates, alpha-blockers, antifungals or grapefruit juice, all of which can affect the intensity of a dose of Cialis — and the side effects of Cialis too.

Be sure to let your healthcare provider know if you have any health conditions or heart conditions before accepting a prescription for this medication.

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If you’re worried Cialis might be too effective for too long during your workday, you might be wondering how long Viagra lasts as an alternative. The Cialis versus Viagra debate is a popular one, but it really comes down to what you want out of your sex life.

Other medications (including Viagra) are often prescribed as in-the-moment solutions — date night is going well, and you’re heading back to her place, so you take a pill to coincide with your best-laid (pun intended) plans. 

Tadalafil, on the other hand, is more of a carpet-bomb medication with regard to your down-and-dirty schedule. Its wider window of efficacy means a morning dose has the capacity to prepare you for some afternoon delight and/or late-night activities.

That’s why tadalafil is an exceptionally better option when your sex life doesn’t fit neatly into your iCal. But if your partner can be game whenever, tadalafil as a daily medication is designed to help you meet the challenge.

Here are the most important facts to know if you’re comparing these medications:

  • Cialis is the longest-lasting ED medication. No other medication promotes sexual activity even close to as long as Cialis.

  • Medications like vardenafil, avanafil and sildenafil (the generics of Levitra, Stendra and Viagra, respectively) last for no more than 12 hours, with most giving you a few hours of results.

  • Viagra (sildenafil) typically lasts four to six hours, with a maximum window of 12 hours.

  • Stendra (avanafil) and Levitra (vardenafil) both can kick in within 30 minutes of taking the medication and typically last around five hours.

  • Your healthcare provider needs to know about other medical conditions you have, including angina and heart issues, before prescribing you these ED medications.

As a reminder, Cialis nor any of the other medications for ED just give you erections. In fact, tadalafil probably couldn’t get you up on its own unless it came wrapped in pictorials from old Playboy magazines. 

Tadalafil and other PDE5 inhibitors merely get the system to operate optimally — you still have to get stimulated and aroused.

ED affects millions of men. And the truth is that while Cialis helps many of them, it’s not always the solution, especially if your ED is a result of stress, low self-esteem, depression, performance anxiety or other mental health issues.

That’s why the list of erectile dysfunction treatments includes therapy and other mental health support.

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If you’re reading this, you may be less than impressed with your penis’s recent performance. But there’s no reason to be embarrassed.

Here’s what to keep in mind:

  • ED is defined as a recurring pattern of distress from an inability to get or stay hard. Medications like Cialis are among the many treatments that can help reduce this distress and produce erections. 

  • Which medication you take and how often you take it depends on your individual needs and lifestyle.

  • Tadalafil can treat ED, so if you’re suffering from unreliable, incomplete or otherwise finicky erections, talk to a healthcare provider about a tadalafil prescription.

  • There are other options. Medications like Stendra, Levitra and Viagra also offer relief from ED symptoms, though they treat ED on an as-needed basis.

  • When used properly, these drugs can help you thwart the physical effects of ED and stride confidently into the bedroom.

  • Taking more than the recommended amount of these drugs won’t make it harder or bigger. That would be like filling your car’s gas tank with premium instead of regular and expecting it to suddenly sprout two extra cylinders.

  • If your ED comes from intimacy issues, self-confidence problems or something else, effective treatment might be more complex than simply getting the mechanics working again. Talk to a therapist or another mental health professional if this sounds like it may apply to you.

If you’re ready to treat ED, we can help. Our online therapy platform is convenient and affordable, and you can get a prescription for Cialis with an online consultation.

We also offer other forms of ED medication, like our hard mint chewable ED meds. Explore your options today.

5 Sources

  1. Evans, J. D., & Hill, S. R. (2015). A comparison of the available phosphodiesterase-5 inhibitors in the treatment of erectile dysfunction: a focus on avanafil. Patient preference and adherence, 9, 1159–1164.
  2. HIGHLIGHTS OF PRESCRIBING INFORMATION: CIALIS (tadalafil) tablets, for oral use . (n.d.).
  3. Silberman M, Stormont G, Leslie SW, et al. Priapism. [Updated 2023 May 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:
  4. Sooriyamoorthy T, Leslie SW. Erectile Dysfunction. [Updated 2023 May 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:
  5. Coward, R. M., & Carson, C. C. (2008). Tadalafil in the treatment of erectile dysfunction. Therapeutics and Clinical Risk Management, 4(6), 1315-1330.
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Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Kelly Brown MD, MBA
Kelly Brown MD, MBA

Dr. Kelly Brown is a board certified Urologist and fellowship trained in Andrology. She is an accomplished men’s health expert with a robust background in healthcare innovation, clinical medicine, and academic research. Dr. Brown is a founding member of Posterity Health where she is Medical Director and leads strategy and design of their Digital Health Platform, an innovative education and telehealth model for delivering expert male fertility care.

She completed her undergraduate studies at University of North Carolina at Chapel Hill (go Heels!) with a Bachelor of Science in Radiologic Science and a Minor in Chemistry. She took a position at University of California Los Angeles as a radiologic technologist in the department of Interventional Cardiology, further solidifying her passion for medicine. She also pursued the unique opportunity to lead departmental design and operational development at the Ronald Reagan UCLA Medical Center, sparking her passion for the business of healthcare.

Dr. Brown then went on to obtain her doctorate in medicine from the prestigious Northwestern University - Feinberg School of Medicine and Masters in Business Administration from Northwestern University - Kellogg School of Management, with a concentration in Healthcare Management. During her surgical residency in Urology at University of California San Francisco, she utilized her research year to focus on innovations in telemedicine and then served as chief resident with significant contributions to clinical quality improvement. Dr. Brown then completed her Andrology Fellowship at Medical College of Wisconsin, furthering her expertise in male fertility, microsurgery, and sexual function.

Her dedication to caring for patients with compassion, understanding, as well as a unique ability to make guys instantly comfortable discussing anything from sex to sperm makes her a renowned clinician. In addition, her passion for innovation in healthcare combined with her business acumen makes her a formidable leader in the field of men’s health.

Dr. Brown is an avid adventurer; summiting Mount Kilimanjaro in Tanzania (twice!) and hiking the incredible Torres del Paine Trek in Patagonia, Chile. She deeply appreciates new challenges and diverse cultures on her travels. She lives in Denver with her husband, two children, and beloved Bernese Mountain Dog. You can find Dr. Brown on LinkedIn for more information.

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