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How Long Does Viagra® (Sildenafil) Last?

Mike Bohl, MD, MPH, ALM

Reviewed by Mike Bohl, MD

Written by Geoffrey C. Whittaker

Published 09/18/2017

Updated 01/10/2024

You’ve just paid the bill for date night dinner when suddenly you realize you forgot to take your Viagra pill. It's a 30-minute walk back to the apartment, and the night is still young. 

Can you slip away to the bathroom, or is it already too late? It's a fair question to ask.

Sildenafil citrate — the active ingredient in brand-name Viagra® — is one of the most widely used and effective erectile dysfunction medications.

For many men, a single tablet of sildenafil is all it takes to improve blood flow and help produce a normal, easily sustained erection

So, how long does Viagra take to work, and how long does it last once it’s in your body? For the most part, brand-name Viagra and generic sildenafil start to work quickly and last a few hours. 

However, there are a few factors that may affect timing. We’ve discussed these below and explained what you need to know if you’re prescribed Viagra as an erectile dysfunction treatment.

Is your stopwatch ready? Pill in hand? Okay, here we go.

Most of the time, Viagra (and sildenafil) should start working in about 30 to 60 minutes after you take it (if Viagra doesn’t work, you’ve got other problems).

This is generally enough time for the medication to get absorbed in your intestinal tract, move into your bloodstream and produce a noticeable effect.

However, the amount of time required for Viagra to start working can vary depending on a range of factors, from the specific response your own body has to this medication, to foods you ate shortly before or after taking it. 

When it’s taken on an empty stomach, Viagra usually begins working rapidly, as the medication is able to enter your digestive system faster.

If you take Viagra or generic sildenafil with or shortly after a large, fatty meal, it may take a little longer to start working. For this reason, avoid a fatty meal if you’re on the clock.  

According to the medication’s FDA label, Viagra lasts for about four hours. 

The technical explanation is that the Viagra half-life is four hours, which means it will still be in your system after four hours, but not necessarily in high enough concentrations to continue producing endless hard-ons. 

The less technical explanation is that most men affected by erectile dysfunction who are appropriately prescribed Viagra are able to get and maintain an erection without any issues for approximately four hours after taking this medication. 

One thing to keep in mind, however, is that you’ll still go into your refractory period after ejaculating — even if you use Viagra — meaning you’ll need to take a break if you plan to have sex again. 

Here’s a big brain reminder for those of you who like making bad decisions: taking a higher dose won’t make you last any longer — though it could cause dangerously low blood pressure — so don’t try overdosing on purpose.

Our full list of Viagra FAQs discusses the amount of time Viagra lasts in more detail, as well as other common questions about how Viagra and generic sildenafil work.

Sildenafil usually lasts for approximately four hours, giving you a large time window in which you can have sex with optimal erectile function. 

This medication — called a phosphodiesterase type 5 inhibitor — inhibits an enzyme in your blood vessels, helping to relax and dilate (open up) those blood vessels. This increases blood flow to your penis, which helps you get hard. 

Sildenafil’s blood vessel opening effects also treat a type of hypertension called pulmonary arterial hypertension, which is high blood pressure in your lungs. 

But we’re here to watch the clock on your peen and not check your other organs, so let’s take a closer look at that. If you want to know more about Viagra and PDE5 inhibitors, check out our blog on how Viagra works.

In one study published in the British Journal of Clinical Pharmacology, men with ED who used sildenafil at a dosage of 100mg were able to attain an “adequate” erection four hours later — a finding that’s consistent with sildenafil’s four-hour half life. 

Of course, there's a little wiggle room in this four-hour window. 

Research suggests that while sildenafil can help produce an erection at four hours post-dose, it may not be as firm as the erection you get one hour after taking sildenafil. 

The active ingredient will continue to affect blood vessels in your penis and increase blood flow — it just might not continue to be enough for sexual activity.

As such, for optimal results, it’s best to time your use of sildenafil so that you’re able to have sex within a few hours after taking this medication, and not cut it close to the four-hour mark unless you really have to. About an hour before the big event is ideal. 

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A variety of factors can affect the amount of time Viagra or generic sildenafil stays active in your body. These include:

  • Your diet. Eating a large fatty meal can slow down your body’s absorption of sildenafil and prevent it from working quickly.

  • Your age. Age can have an impact on your body’s ability to absorb medication. If you’re older than 65 years old or if you have hepatic and/or renal impairment, it may take longer for your body to process Viagra.

  • Your alcohol consumption. Consuming a significant amount of alcohol may affect your sexual function and make it more difficult to maintain an erection. However, it isn’t clear if alcohol affects the amount of time sildenafil lasts.

  • Your sildenafil dosage. Although sildenafil’s half-life stays the same regardless of your dosage, taking a larger dose of Viagra or generic sildenafil may cause you to experience slightly longer-lasting effects. That said, you should still only take what you are prescribed.

  • Your mental well-being. Several psychological factors could make treatment for erectile dysfunction less effective, including depression, stress or feelings of sexual performance anxiety.

  • Your overall health. Some medical conditions, such as diabetes and multiple sclerosis (MS) can affect your erectile function and whether medications like sildenafil are effective for you.

  • Your use of other medications. Certain medications, such as antidepressants, blood pressure drugs, antiandrogens, tranquilizers and others, can make ED symptoms more severe and may affect whether sildenafil works.

If you’re prescribed Viagra or generic sildenafil and feel worried that it isn’t working for as long as it should, it’s important to inform your healthcare provider. 

They may suggest adjusting your dosage or making other changes to the way you use your medication. 

Because the half-life of Viagra’s isn’t something you can change, there’s no simple way to make this medication last for longer once it’s in your body.

However, there are several things that you can do after you take Viagra to ensure it is as effective as possible:

  • Take sildenafil or Viagra as prescribed. Make sure to closely follow your healthcare provider’s instructions and take Viagra or generic sildenafil at the prescribed dosage.

  • Avoid high-fat meals. As you already know, eating a high-fat meal could affect the amount of time required for Viagra to start working and reduce its effectiveness.

  • Don’t consume alcohol. It’s best not to drink alcohol while using Viagra, as this may have a negative effect on your sexual performance.

  • Take it easy and relax. Try to create a relaxing mood before sex to prevent feelings of stress, anxiety or general worry from affecting your sex life. 

Choose your chew

Assuming it’s used correctly, Viagra doesn’t cause lasting side effects. It stops working after four hours and doesn’t have any long-term adverse effects on your body.

As we mentioned above, the half-life of sildenafil is approximately four hours, meaning it takes a total of four hours for the amount of sildenafil in your bloodstream to decrease by 50 percent.

This means that a typical dose of Viagra or generic sildenafil will remain “in your body” for about one day after you take it, albeit at increasingly smaller doses that have minimal to no noticeable effects on your health. 

Eventually, Viagra will no longer be present in your bloodstream or tissue and it will produce no effects within your body. 

Of course, like with most medications, PDE5 inhibitors like Viagra are associated with a number of side effects that you’ll need to watch for:

  • Common side effects can include flu-like symptoms, headaches and dizziness.

  • Serious side effects like prolonged erection (or priapism) and sudden loss of vision or hearing are risks of ED treatment. If you have an erection lasting more than four hours, seek medical attention immediately. 

To avoid negative drug interactions, you should not take Viagra with nitroglycerin or other nitrates, nor should you take it with nitrites or alpha blockers.

For more, check out our guide to the potential side effects of Viagra.

Although Viagra is the most popular medication for treating ED, it certainly isn’t the only treatment option in its category. Other common medications for treating ED taken orally include Cialis®, Levitra® and Stendra®, all of which work similarly in the body.

  • Cialis (tadalafil) provides relief from ED for significantly longer per dose than Viagra. Most of the time, one dose of Cialis will take effect after 30 minutes to two hours, and it can last for as long as 36 hours.

  • Levitra (vardenafil), on the other hand, has a similar half-life to Viagra. Levitra contains vardenafil and can take about 60 minutes to start working. Once it’s absorbed by your body, its effects usually last for approximately four to five hours.

  • Stendra (avanafil) is one of the newer kids on the block as far as ED meds go. It comes out swinging with a terminal half-life of five hours — slightly longer than Viagra — which means you can generally expect a normal dose of Stendra to provide relief from ED for five hours. Stendra is also quick to start working, with some men experiencing improved erections in as little as 15 minutes after taking it.

Besides oral ED medications, there are other options such as the injectable, alprostadil, or a newly FDA-authorized topical gel.

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How long does Viagra last? Assuming you take it without a fatty meal, you can expect Viagra to start working in around 30 minutes to one hour and provide relief from ED for approximately four hours at a time.

We just spent this whole article answering that question, so we won’t repeat ourselves anymore. What we will do, however, is leave you with a cheat sheet of the most important takeaways:

  • Viagra won’t make you hard without sexual stimulation — it helps allow blood to flow to your penis, but this process only starts when you get aroused.

  • If Viagra doesn’t work effectively for you, it’s best to let your healthcare provider know as soon as you can. You may need to adjust your dosage of Viagra or make other changes to the way you use your medication.  

  • If you’re looking for extended relief from erectile dysfunction, a longer-lasting medication such as tadalafil may be your best bet.

  • Non-prescription supplements are not a safe alternative to FDA-approved ED medications. Read more in our guide to gas station sex pills.

We offer several evidence-based, FDA-approved ED medications online, including Viagra and generic sildenafil. 

To get started, consider taking part in an online consultation for erectile dysfunction to talk to a licensed healthcare provider and learn more about your options. 

11 Sources

  1. Dhaliwal, A. & Gupta, M. (2022, May 20). PDE5 Inhibitors. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK549843/
  2. Smith, B.P. & Babos, M. (2022, September 19). Sildenafil. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK558978/
  3. VIAGRA- sildenafil citrate tablet, film coated. (2017, August). Retrieved from https://www.accessdata.fda.gov/spl/data/40578e70-350a-4940-9630-55d90989c146/40578e70-350a-4940-9630-55d90989c146.xml
  4. Eardley, I., Ellis, P., Boolell, M. & Wulff, M. (2002, February). Onset and duration of action of sildenafil for the treatment of erectile dysfunction. British Journal of Clinical Pharmacology. 53 (Suppl 1), 61S-65S. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1874251/
  5. As You Age: You and Your Medicines. (2019, February 19). Retrieved from https://www.fda.gov/drugs/information-consumers-and-patients-drugs/you-age-you-and-your-medicines
  6. Symptoms & Causes of Erectile Dysfunction. (2017, July). Retrieved from https://www.niddk.nih.gov/health-information/urologic-diseases/erectile-dysfunction/symptoms-causes
  7. Sildenafil. (2018, January 15). Retrieved from https://medlineplus.gov/druginfo/meds/a699015.html
  8. CIALIS- tadalafil tablet, film coated. (2017, May). Retrieved from https://www.accessdata.fda.gov/spl/data/05dbd8b6-1b9d-436a-a67c-8a16713f753f/05dbd8b6-1b9d-436a-a67c-8a16713f753f.xml
  9. LEVITRA (vardenafil hydrochloride) tablets, for oral use. (2014, April). Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2014/021400s017lbl.pdf
  10. STENDRA- avanafil tablet. (2017, August). Retrieved from https://www.accessdata.fda.gov/spl/data/41d308f4-9a6a-48bb-b7a0-d63da9818078/41d308f4-9a6a-48bb-b7a0-d63da9818078.xml
  11. Arackal BS, Benegal V. Prevalence of sexual dysfunction in male subjects with alcohol dependence. Indian J Psychiatry. 2007 Apr;49(2):109-12. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2917074/
Editorial Standards

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.

Mike Bohl, MD

Dr. Mike Bohl is a licensed physician, a Medical Advisor at Hims & Hers, and the Director of Scientific & Medical Content at a stealth biotech startup, where he is involved in pharmaceutical drug development. Prior to joining Hims & Hers, Dr. Bohl spent several years working in digital health, focusing on patient education. He has also worked in medical journalism for The Dr. Oz Show (receiving recognition for contributions from the National Academy of Television Arts and Sciences when the show won Outstanding Informative Talk Show at the 2016–2017 Daytime Emmy® Awards) and at Sharecare. He is a Medical Expert Board Member at Eat This, Not That! and a Board Member at International Veterinary Outreach.

Dr. Bohl obtained his Bachelor of Arts and Doctor of Medicine from Brown University, his Master of Public Health from Columbia University, and his Master of Liberal Arts in Extension Studies—Journalism from Harvard University. He is currently pursuing a Master of Business Administration and Master of Science in Healthcare Leadership at Cornell University. Dr. Bohl trained in internal medicine with a focus on community health at NYU Langone Health.

Dr. Bohl is Certified in Public Health by the National Board of Public Health Examiners, Medical Writer Certified by the American Medical Writers Association, a certified Editor in the Life Sciences by the Board of Editors in the Life Sciences, a Certified Personal Trainer and Certified Nutrition Coach by the National Academy of Sports Medicine, and a Board Certified Medical Affairs Specialist by the Accreditation Council for Medical Affairs. He has graduate certificates in Digital Storytelling and Marketing Management & Digital Strategy from Harvard Extension School and certificates in Business Law and Corporate Governance from Cornell Law School.

In addition to his written work, Dr. Bohl has experience creating medical segments for radio and producing patient education videos. He has also spent time conducting orthopedic and biomaterial research at Case Western Reserve University and University Hospitals of Cleveland and practicing clinically as a general practitioner on international medical aid projects with Medical Ministry International.

Dr. Bohl lives in Manhattan and enjoys biking, resistance training, sailing, scuba diving, skiing, tennis, and traveling. You can find Dr. Bohl on LinkedIn for more information.

Publications

  • Younesi, M., Knapik, D. M., Cumsky, J., Donmez, B. O., He, P., Islam, A., Learn, G., McClellan, P., Bohl, M., Gillespie, R. J., & Akkus, O. (2017). Effects of PDGF-BB delivery from heparinized collagen sutures on the healing of lacerated chicken flexor tendon in vivo. Acta biomaterialia, 63, 200–209. https://www.sciencedirect.com/science/article/abs/pii/S1742706117305652?via%3Dihub

  • Gebhart, J. J., Weinberg, D. S., Bohl, M. S., & Liu, R. W. (2016). Relationship between pelvic incidence and osteoarthritis of the hip. Bone & joint research, 5(2), 66–72. https://boneandjoint.org.uk/Article/10.1302/2046-3758.52.2000552

  • Gebhart, J. J., Bohl, M. S., Weinberg, D. S., Cooperman, D. R., & Liu, R. W. (2015). Pelvic Incidence and Acetabular Version in Slipped Capital Femoral Epiphysis. Journal of pediatric orthopedics, 35(6), 565–570. https://journals.lww.com/pedorthopaedics/abstract/2015/09000/pelvic_incidence_and_acetabular_version_in_slipped.5.aspx

  • Islam, A., Bohl, M. S., Tsai, A. G., Younesi, M., Gillespie, R., & Akkus, O. (2015). Biomechanical evaluation of a novel suturing scheme for grafting load-bearing collagen scaffolds for rotator cuff repair. Clinical biomechanics (Bristol, Avon), 30(7), 669–675. https://www.clinbiomech.com/article/S0268-0033(15)00143-6/fulltext

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