How long does Viagra last and when does it start to work?

Viagra, a brand name for sildenafil, is a type of medicine that healthcare providers use to treat erectile dysfunction (ED). It works by relaxing muscles to improve blood flow, making it easier to get and maintain an erection. Viagra starts to work 30 minutes after taking it, but hits peak levels in your body after 60–120 minutes. It can last in your body for up to four to five hours, but your age, health, and diet all affect the exact amount of time it will work. Even if the medication doesn’t work after 30 minutes, you should never take more than the recommended dose.

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Disclaimer

If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

Erectile dysfunction (ED)—when a person experiences trouble getting or maintaining an erection—can be stressful, and worrying about how long Viagra lasts will not help the situation. Typically, Viagra—a medication healthcare providers prescribe to treat ED—lasts for about 4–5 hours, but because erectile dysfunction is so common, affecting 30–50 million people in the U.S., this time-frame is not one-size-fits-all. Several factors can come into play to determine both how long Viagra takes to work and how long it lasts (Sooriyamoorthy, 2021).

Read on to learn more about the timing of this effective drug.

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How long does Viagra last?

It’s important to remember that you don’t need to have an erection for Viagra to work. Viagra’s active ingredient is sildenafil citrate, a PDE5 inhibitor that relaxes muscles in the penis and improves blood flow in order to enable people with penises to have erections. It is neither required nor healthy to have an erection the entire time Viagra is in your system (Smith, 2021).

Viagra can stay active in your system for up to 4–5 hours, depending on other factors. Most healthcare providers suggest that you take it 30–60 minutes before engaging in sexual activity, but you can take it up to four hours before intercourse. Some of the medicine may be in your body longer but in concentrations too low to cause any effect (Zucchi, 2019; DailyMed, 2020).

Many different factors affect how long Viagra works for someone, including the dose of the medication, other medications or supplements you’re taking, and your age, diet, overall health, and psychological state.

How long does Viagra take to work?

Viagra starts working in as little as 30 minutes after taking it. But it can take up to two hours to be effective if you take the drug with a meal (Zucchi, 2019).

So, how does it work? A lot has to go right in your body for an erection to happen. Even if we ignore the mental and emotional aspects of arousal and how they can lower sex drive, it’s a complicated dance physiologically involving many systems of your body.

A messenger called cGMP tells erectile tissue to relax, which allows blood to flow into the penis. But at the same time, the blood vessels that take the blood back to your heart constrict so that more blood is trapped in the penis. An enzyme called phosphodiesterase-5 (PDE-5) breaks down cGMP so that the erect penis can relax (Smith, 2021).

That’s where Viagra comes in. Viagra is a PDE-5 inhibitor, so it blocks this enzyme from breaking down the messenger that kick-starts the blood flow needed to get and maintain an erection (Smith, 2021). The medication doesn’t just cause spontaneous erections on its own, though—it just makes them easier to form. You’ll still also need to be sexually aroused to get an erection.

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How to use Viagra

Timing is essential when it comes to taking Viagra. As mentioned, you should ideally take Viagra about 30–60 minutes before sex for maximum effect. You can take Viagra with or without food, but know that fatty foods decrease drug absorption and increase how long sildenafil takes to start working—meaning taking sildenafil on an empty stomach may allow it to work faster (Zucchi, 2019).

If you think it is not working after 30–60 minutes, do not take more medication. There is an association between higher doses and higher rates of side effects. Talk to your healthcare provider if you feel like your Viagra or sildenafil is not working for you.

How much Viagra should you take?

Viagra (or generic sildenafil; see Important Safety Information) tablets typically come in three doses: 25 mg, 50 mg, and 100 mg.

It’s most common for people to start with the 50 mg dosage. If you’re on a higher dose, the effects of Viagra may last longer. It may take more time for older people to eliminate Viagra from their bodies, meaning the medicine may last longer in their bodies. This may also be the case for people with medical conditions like liver or kidney disease (DailyMed, 2020).

Viagra side effects

The most common side effects of Viagra include (Smith, 2021):

• Headaches
• Facial flushing
• Indigestion/heartburn
• Back pain
• Stuffy nose
• Nausea

Priapism, a persistent and painful erection that can last more than four hours, is the most infamous potential side effect of Viagra—fortunately, it is not a common one. But priapism is a serious health condition that requires immediate medical attention. You should follow medical advice on your recommended dose of Viagra and not take more if it doesn’t work in 30 minutes (Smith, 2021).

Other serious but less common side effects include hearing loss (which can be sudden), severe low blood pressure, and vision loss, which can be in one or both eyes (Smith, 2021).

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Risk factors and warnings

Some medical conditions can interact negatively with Viagra. If you have any of the following, speak with your healthcare provider before taking Viagra.

Blood pressure issues

Viagra relaxes the muscles of your blood vessels to improve blood flow. However, this can also cause low blood pressure. If your blood pressure drops too low, you can develop hypotension and may experience fainting, dizziness, etc. You should not take Viagra if you already have low blood pressure, as Viagra may worsen the condition.

Similarly, if you have high blood pressure (hypertension) and use medications to lower it (antihypertensives), taking Viagra can cause your blood pressure to drop even further. This is especially true if you are taking an alpha-blocker antihypertensive, like terazosin. Alpha-blockers like tamsulosin (brand name Flomax) are also used to treat prostate issues and can have the same low blood pressure effect if taken with Viagra (DailyMed, 2020).

Heart problems

People with heart conditions, such as a history of a recent stroke, heart attack, or chest pain, should check with their healthcare provider before taking Viagra (DailyMed, 2020).

Vision concerns

Viagra may increase your risk of vision loss due to non-arteritic ischemic optic neuropathy (NAION), essentially a small stroke to the optic nerve. If you have a history of or risk factors for NAION, you should use caution with Viagra. Viagra has also been reported to cause changes in color vision in some people (DailyMed, 2020).

Lastly, anyone with an allergy or hypersensitivity reaction to Viagra should not use the medication.

Drug interactions with Viagra

Before starting Viagra or sildenafil, be sure to tell your healthcare provider about any other medications you are taking to avoid potential drug interactions. Some drugs, in particular, include:

• Nitrates: Viagra is contraindicated if you are also taking nitrates (e.g., nitroglycerin) for your chest pain. The combination of these two drugs can make your blood pressure drop to life-threatening low levels. You need to wait at least 24 hours after taking Viagra before you can safely take nitrates (Smith, 2021).
• Ritonavir: Ritonavir affects the CYP3A4 enzyme in the liver—this is the system responsible for breaking down sildenafil. If taken with Viagra, ritonavir may raise Viagra concentrations in your blood and increase your risk of side effects like low blood pressure and prolonged erections (DailyMed, 2020).
• PDE5 inhibitors: You should not combine sildenafil with other PDE5 inhibitors (like Revatio for pulmonary hypertension) or other erectile dysfunction treatments (like Cialis, Levitra, etc.) to avoid the potential risk of a drop in blood pressure (DailyMed, 2020).

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Alternatives to Viagra

Common alternatives to Viagra include Cialis (tadalafil; see Important Safety Information) and Levitra (vardenafil). If taking a pill before sexual activity doesn’t work for you, Daily Cialis may be an option. Taken daily, this medication provides a low dose of tadalafil to be ready for sex anytime. Levitra acts similarly to Viagra and, like the blue pill, needs to be taken within a timeframe before sexual activity (Zucchi, 2019).

When to see a healthcare provider

In some cases, erectile dysfunction is due to underlying causes. Treating those conditions may help resolve the problem without ED medications. In other cases, performance anxiety may be the cause of erectile dysfunction. Addressing the mental and emotional aspects of sexual stimulation may also help. Your healthcare provider can help you navigate the different ED causes and the risks and benefits of various treatment options.

If you already take Viagra, seek medical advice from your healthcare provider if you feel that the medicine is not working for you.

References

1. DailyMed. (2020). Viagra- sildenafil citrate tablet, film-coated. Retrieved on November 2, 2021 from https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=a2a9f459-e692-4e85-83b0-a35fbf35e91b
2. Smith, B. P., & Babos, M. (2021). Sildenafil. [Updated Jun 29, 2021]. In: StatPearls [Internet]. Retrieved on Nov. 4, 2021 from https://www.ncbi.nlm.nih.gov/books/NBK558978/
3. Sooriyamoorthy, T., & Leslie, S. W. (2021). Erectile dysfunction. [Updated Aug 12, 2021]. In: StatPearls [Internet]. Retrieved on Nov. 4, 2021 from https://www.ncbi.nlm.nih.gov/books/NBK562253/
4. Zucchi, A., Costantini, E., Scroppo, F. I., Silvani, M., Kopa, Z., Illiano, E., et al. (2019). The first-generation phosphodiesterase 5 inhibitors and their pharmacokinetic issue. Andrology, 7(6), 804–817. doi: 10.1111/andr.12683. Retrieved from https://pubmed.ncbi.nlm.nih.gov/31350821/

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Important Safety Information for Sildenafil (Viagra)

What are the most important things I need to know about VIAGRA® (sildenafil citrate) 25 mg, 50 mg, and 100 mg tablets and generic VIAGRA®?

Discuss your health with your doctor to ensure that you are healthy enough for sex. If you experience chest pain, dizziness, or nausea during sex, seek immediate emergency medical attention.

• VIAGRA® and generic VIAGRA® can cause serious side effects. Serious, but rare, side effects include:
  • an erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, seek emergency medical attention right away. If it is not treated right away, priapism can permanently damage your penis.
  • sudden vision loss in one or both eyes. Sudden vision loss in one or both eyes can be a sign of a serious eye problem called non-arteritic anterior ischemic optic neuropathy (NAION). Stop taking VIAGRA and call your healthcare provider right away if you have any sudden vision loss
  • sudden hearing decrease or hearing loss. Some people may also have ringing in their ears (tinnitus) or dizziness. If you have these symptoms, stop taking VIAGRA and contact a doctor right away

  Who should not take VIAGRA® or generic VIAGRA®?

  Do not take VIAGRA® or generic VIAGRA® if you:

  • Take any medicines called nitrates, often prescribed for chest pain, or guanylate cyclase stimulators like Adempas (riociguat) for pulmonary hypertension. Your blood pressure could drop to an unsafe level
  • Are allergic to sildenafil, as contained in VIAGRA® and REVATIO®, or any of the ingredients in VIAGRA® or generic VIAGRA® tablets.
  • Are a women or a child

  When should I call my primary provider?

  Call your primary provider right away if you:

  • Have an erection that lasts longer than 4 hours
  • Experience a sudden loss of vision in one or both eyes
  • Experience a sudden decrease in or loss of hearing
  • Experience chest pain, dizziness, or nausea during sex
  • Take too much Viagra or sildenafil citrate

  If you are experiencing a medical emergency, call 911 or seek immediate medical attention.

  What are the most common side effects of VIAGRA® and generic VIAGRA®?

  The most common side effects are:

  • headache
  • flushing
  • upset stomach
  • abnormal vision, such as changes in color vision (such as having a blue color tinge) and blurred vision
  • stuffy or runny nose
  • back pain
  • muscle pain
  • nausea
  • dizziness
  • rash

  What should I tell my Roman-affiliated provider before taking VIAGRA® and generic VIAGRA®?

  Before you take VIAGRA® or generic VIAGRA® , tell your healthcare provider if you:

  • Have or have had heart problems such as a heart attack,irregular heartbeat, angina, chest pain, narrowing of the aortic valve, or heart failure
  • Have had heart surgery within the last 6 months
  • Have pulmonary hypertension
  • Have had a stroke
  • Have low blood pressure, or high blood pressure that is not controlled
  • Have a deformed penis shape
  • Have had an erection that lasted for more than 4 hours
  • Have problems with your blood cells such as sickle cell anemia, multiple myeloma, or leukemia
  • Have retinitis pigmentosa, a rare genetic (runs in families) eye disease
  • Have ever had severe vision loss, including an eye problem called NAION
  • Have bleeding problems
  • Have or have had stomach or intestinal ulcers
  • Have liver problems
  • Have kidney problems or are having kidney dialysis
  • Have any other medical conditions

  Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

  VIAGRA may affect the way other medicines work, and other medicines may affect the way VIAGRA works, causing side effects.

  Especially tell your healthcare provider if you take any of the following:

  • Medicines called nitrates
  • Medicines called guanylate cyclase stimulators such as Adempas® (riociguat)
  • Medicines called alpha-blockers such as Hytrin® (terazosin HCl), Flomax® (tamsulosin HCl), Cardura® (doxazosin mesylate), Minipress® (prazosin HCl), Uroxatral® (alfuzosin HCl), Jalyn® (dutasteride and tamsulosin HCl), or Rapaflo® (silodosin). Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure. In some patients, the use of VIAGRA® with alpha-blockers can lead to a drop in blood pressure or to fainting
  • Medicines called HIV protease inhibitors, such as ritonavir (Norvir®), indinavir sulfate (Crixivan®), saquinavir (Fortovase® or Invirase®), or atazanavir sulfate (Reyataz®)
  • Oral antifungal medicines, such as ketoconazole (Nizoral®) and itraconazole (Sporanox®)
  • Antibiotics, such as clarithromycin (Biaxin®), telithromycin (Ketek®), or erythromycin
  • Other medicines that treat high blood pressure
  • Other medicines or treatments for ED
  • VIAGRA® contains sildenafil, which is the same medicine found in another drug called REVATIO®. REVATIO® is used to treat a rare disease called pulmonary arterial hypertension (PAH). VIAGRA® should not be used with REVATIO® or with other PAH treatments containing sildenafil or any other PDE5 inhibitors (such as Adcirca [tadalafil])

  Withholding or providing inaccurate information about your health and medical history in order to obtain treatment may result in harm, including, in some cases, death.

  What is the FDA-approved use of VIAGRA® and generic VIAGRA®?

  VIAGRA® (sildenafil citrate) is prescription medicine used to treat erectile dysfunction (ED).

  Roman-affiliated doctors may prescribe VIAGRA® or generic VIAGRA® for the treatment of premature ejaculation (PE), if they believe in their medical judgment that it is an appropriate course of treatment. While this is not an FDA-approved use of the drug, the American Urological Association has included the use of sildenafil citrate in the treatment of PE in its Guideline on the Pharmacologic Management of Premature Ejaculation.

  You are encouraged to report negative side effects of prescription products to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

  Please see the full Prescribing Information for complete safety information.

  Product names referenced herein are trademarks of their respective owners.

  Important Safety Information for Tadalafil (Cialis)

  What Is The Most Important Information I Should Know About CIALIS® (tadalafil) and generic CIALIS®?

  • CIALIS® and generic CIALIS® can cause serious side effects. Serious, but rare, side effects include:
    • An erection that won’t go away (priapism). If you get an erection that lasts more than 4 hours, get medical help right away. Priapism must be treated as soon as possible or lasting damage can happen to your penis, including the inability to have erections.
    • Changes in vision. Color vision changes, such as seeing a blue tinge (shade) to objects or having difficulty telling the difference between the colors blue and green.
    • Sudden decrease or loss of vision. In rare instances, men taking PDE5 inhibitors (oral erectile dysfunction medicines, including CIALIS® and generic CIALIS®) reported a sudden decrease or loss of vision in one or both eyes. It is uncertain whether PDE5 inhibitors directly cause the vision loss. If you experience sudden decrease or loss of vision, stop taking PDE5 inhibitors, including CIALIS® and generic CIALIS®, and call a healthcare provider right away.
    • Sudden loss or decrease in hearing. Sudden loss or decrease in hearing, sometimes with ringing in the ears and dizziness, has been rarely reported in people taking PDE5 inhibitors, including CIALIS® and generic CIALIS®. It is not possible to determine whether these events are related directly to the PDE5 inhibitors, to other diseases or medications, to other factors, or to a combination of factors. If you experience these symptoms, stop taking CIALIS® and generic CIALIS® and contact a healthcare provider right away.
    • ED is a condition where the penis does not fill with enough blood to harden and expand when a man is sexually excited, or when he cannot keep an erection. A man who has trouble getting or keeping an erection should see his healthcare provider for help if the condition bothers him.
    • CIALIS® and generic CIALIS® help increase blood flow to the penis and may help men with ED get and keep an erection satisfactory for sexual activity. Once a man has completed sexual activity, blood flow to his penis decreases, and his erection goes away. Some form of sexual stimulation is needed for an erection to happen with CIALIS® or generic CIALIS®.
    • CIALIS® and generic CIALIS® do not:
      • Cure ED
      • Increase a man’s sexual desire
      • Protect a man or his partner from sexually transmitted diseases, including HIV. Speak to your healthcare provider about ways to guard against sexually transmitted diseases.
      • Serve as a male form of birth control
      • Take CIALIS® or generic CIALIS® exactly as your healthcare provider prescribes it. Your healthcare provider will prescribe the dose that is right for you. Do not change your dose or the way you take CIALIS® or generic CIALIS® without talking to your healthcare provider.

      Who Should Not Take CIALIS® or generic CIALIS®?

      Do not take CIALIS® or generic CIALIS® if you:

      • Have severe liver disease. Tell your doctor if you have mild to moderate liver disease as you may need dosage reductions.
      • Have severe kidney disease. Tell your doctor if you have mild to moderate kidney disease as you may need dosage reductions
      • Take any medicines called “nitrates”
      • Use recreational drugs called “poppers” like amyl nitrite and butyl nitrite
      • Take any medicines called guanylate cyclase stimulators, such as riociguat
      • Are allergic to CIALIS®, tadalafil or ADCIRCA®, or any of its ingredients

      When should I call my primary provider?

      Call your primary provider right away if you:

      • Have an erection that lasts longer than 4 hours
      • Experience a sudden loss of vision in one or both of your eyes
      • Experience a sudden decrease or loss hearing
      • Take too much CIALIS® or generic CIALIS®
      • Have an allergic reaction to CIALIS® or generic CIALIS®
      • Symptoms of an allergic reaction may include:
      • Rash
      • Hives
      • Swelling of the lips, tongue, or throat
      • Difficulty breathing or swallowing

      Call your healthcare provider or get help right away if you have any of the symptoms of an allergic reaction listed above.

      If you are experiencing a medical emergency, call 911 or seek immediate medical attention.

      What Should I Tell My Roman-affiliated Provider Before Taking CIALIS® and generic CIALIS®?

      Tell your Roman-affiliated provider about all your medical problems, including if you:

      • Have heart problems such as angina, heart failure, irregular heartbeats, or have had a heart attack. Ask your healthcare provider if it is safe for you to have sexual activity. You should not take CIALIS® and generic CIALIS® if your healthcare provider has told you not to have sexual activity because of your health problems.
      • Have pulmonary hypertension
      • Have low blood pressure or have high blood pressure that is not controlled
      • Have had a stroke
      • Have liver problems
      • Have kidney problems or require dialysis
      • Have retinitis pigmentosa, a rare genetic (runs in families) eye disease
      • Have ever had severe vision loss, including a condition called NAION
      • Have stomach or intestinal ulcers
      • Have a bleeding problem
      • Have a deformed penis shape or Peyronie’s disease
      • Have had an erection that lasted more than 4 hours
      • Have blood cell problems such as sickle cell anemia, multiple myeloma, or leukemia

      Tell your healthcare provider about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

      Especially tell your healthcare provider if you take any of the following:

      • Medicines called nitrates
      • Medicines called guanylate cyclase stimulators, such as riociguat (Adempas®), used to treat pulmonary hypertension
      • Medicines called alpha blockers. These include Hytrin® (terazosin HCl), Flomax® (tamsulosin HCl), Cardura® (doxazosin mesylate), Minipress® (prazosin HCl), Uroxatral® (alfuzosin HCl), 4 Jalyn® (dutasteride and tamsulosin HCl) or Rapaflo® (silodosin). Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure. If CIALIS® or generic CIALIS® is taken with certain alpha blockers, your blood pressure could suddenly drop. You could get dizzy or faint.
      • Other medicines to treat high blood pressure (hypertension)
      • Medicines called HIV protease inhibitors, such as ritonavir (Norvir® , Kaletra® )
      • Oral antifungals such as ketoconazole (Nizoral® ), itraconazole (Sporanox® )
      • Antibiotics such as clarithromycin (Biaxin® ), telithromycin (Ketek® ), erythromycin (several brand names exist. Please consult your healthcare provider to determine if you are taking this medicine).
      • Other medicines or treatments for ED.
      • Tadalafil is also marketed as ADCIRCA® for the treatment of pulmonary arterial hypertension. Do not take both CIALIS® or generic CIALIS® and ADCIRCA®. Do not take sildenafil citrate (Revatio®, Viagra®) with CIALIS® or generic CIALIS®.

      Withholding or providing inaccurate information about your health and medical history in order to obtain treatment may result in harm, including, in some cases, death.

      What are the most common side effects of CIALIS® or generic CIALIS®?

      The most common side effects with CIALIS® and generic CIALIS® are:

      • Headache
      • Indigestion
      • Back pain
      • Muscle aches
      • Flushing
      • Stuffy or runny nose

      What is the FDA-approved Use of CIALIS® and generic CIALIS®?

      CIALIS® and generic CIALIS® are prescription medicines used to treat erectile dysfunction (ED), symptoms of benign prostatic hyperplasia (BPH), or both.

      Roman-affiliated doctors may prescribe CIALIS® for the treatment of premature ejaculation (PE), if they believe in their medical judgment that it is an appropriate course of treatment.

      You are encouraged to report negative side effects of prescription products to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

      Please see the full Prescribing Information for complete safety information.