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Last updated: Sep 02, 2022
8 min read

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

 

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 US, 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, 2022). 

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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 (see Important Safety Information) to work. Viagra’s active ingredient is sildenafil citrate, a PDE-5 inhibitor that relaxes muscles in the penis and improves blood flow 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, 2022).

Viagra can stay active in your system for up to 4–5 hours, depending on other factors. Most healthcare providers suggest 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, 2017). 

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

What factors affect how long Viagra lasts?

A few major factors can affect how long Viagra will last after you take it.

Dosage

The amount of Viagra you take affects the way it works with your system and how long it stays in your body. Taking a higher dose, such as the largest available 100 mg tablet, may result in a longer-lasting effect than ingesting a smaller dose (Smith, 2022). Note: Consult your physician to ensure you’re taking the safest amount of Viagra for you, depending on your personal health circumstances.

Age

The effects of Viagra tend to last longer for older men over 65. This is because age comes with a slower metabolism process (DailyMed, 2017). Hence, Viagra can remain in your system, staying active for longer. Typically, it can last up to four hours, with your liver taking more time to metabolize the drug.

Food and overall diet

Eating heavily right before Viagra intake can considerably slow down the absorption of the drug and, in turn, delay its desired effects. Fatty foods can 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. While this does not mean that you should deprive yourself of meals, you should consider waiting at least an hour after eating before taking Viagra to allow it to have the fullest effect (Zucchi, 2019).

Alcohol

It is most advisable to refrain from consuming alcohol when you’re taking Viagra. If it can’t be avoided, it is best to veer from excessive drinking. Drinking alcoholic beverages while taking Viagra has not been shown to cause adverse effects. However, alcohol can negatively impact the male reproductive system as a whole (Emanuele, n.d).

Medications

Certain medications should not be taken alongside Viagra. Interactions between Viagra and other medicines may change the expected results from the former. In addition, this may also cause more serious health complications (DailyMed, 2017). 

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 big 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, an erection is a complicated physiological dance 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, 2022). 

That’s where Viagra comes in. Viagra is a PDE-5 inhibitor, which blocks this enzyme from breaking down the messenger that kick-starts the blood flow needed to get and maintain an erection (Smith, 2022). The medication doesn’t cause spontaneous erections on its own, though—it just makes them easier to form. You’ll still need to be sexually aroused to get an erection.

When to take Viagra and how to take it

Timing is essential when it comes to taking Viagra. The best time to take Viagra is about 30–60 minutes before sex for maximum effect. You can take Viagra with or without food, but know that high-fat mealsmay increase how long sildenafil takes to start working (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 Viagra) 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, 2017).

Before and after Viagra

Wondering what to expect after taking Viagra?

Well, it won’t take effect right away. Viagra will begin to work around one hour after taking it. It needs this time to absorb into your blood completely. This is when Viagra reaches its peak concentration in your bloodstream and, thus, its optimal effect.

The drug will cause the blood vessels in the penis to relax, allowing increased blood flow to the organ and leading it to expand for an easier and stronger erection for a longer time.

A myth about Viagra is that it forces an erection. In fact, it does not, on its own, cause the erection. It assists with getting a full erection with proper sexual stimulation. When you are no longer turned on or sexually aroused, the erection should stop as normal.

Four hours after Viagra intake, the drug, now metabolized in the system, will reach its half-life (i.e., your blood is rid of half of the medication). This does not necessarily mean the effects are completely eradicated. Some people find that Viagra is still effective 18 hours after taking it (DailyMed, 2017; Smith, 2022).

After 24 hours, most of the sildenafil will leave the bloodstream, and the effects of the Viagra should subside (Smith, 2022). 

Viagra side effects

The most common side effects of Viagra include (Smith, 2022):

  • 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, 2022). 

Other serious side effects that are less common include (Smith, 2022):

  • Hearing loss (which can be sudden)
  • Irregular heartbeat
  • Severe low blood pressure
  • Blurred vision or vision loss, which can be in one or both eyes

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 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, 2017). 

Heart problems

People with heart conditions, such as a history of heart disease, heart failure, or those who’ve suffered recent chest pains or a heart attack, should check with their healthcare provider before taking Viagra (DailyMed, 2017). 

Vision concerns

Viagra may increase your risk of vision loss due to non-arteritic ischemic optic neuropathy (NAION), essentially a small stroke of 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, 2017).

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 prescription drugs 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 chest pain. The combination of these two drugs can make your blood pressure drop to life-threateningly low levels. You need to wait at least 24 hours after taking Viagra before you can safely take nitrates (Smith, 2022). 
  • 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, 2017).  
  • PDE-5 inhibitors: You should not combine sildenafil with other PDE-5 inhibitors (like Revatio for pulmonary arterial hypertension) or other erectile dysfunction treatments, to avoid the potential risk of a drop in blood pressure (DailyMed, 2017).

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 specific 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. 

Viagra FAQs

Many people have questions about Viagra before or after starting the medication. Here are answers to some common questions. 

What is Viagra?

Viagra is a brand name for sildenafil. This medication is also used to help with erectile dysfunction (ED). 

How long do you stay hard with Viagra? 

With adequate sexual stimulation, Viagra can help a person stay hard for up to four hours.

How long does it take for Viagra to peak?

Viagra should begin to work within 30 minutes after a person takes it. However, it will reach its peak after 60 to 120 minutes. 

How much Viagra should I take the first time?

The recommended starting dose of Viagra is 50 mg. 

References

  1. DailyMed. (2017). Viagra – sildenafil citrate tablet, film-coated. Retrieved on Aug. 14, 2022 from https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=a2a9f459-e692-4e85-83b0-a35fbf35e91b 
  2. Emanuele, M. A. & Emanuele, N. (n.d.). Alcohol and the male reproductive system. National Institute on Alcohol Abuse and Alcoholism. Retrieved on Aug. 14, 2022 from https://pubs.niaaa.nih.gov/publications/arh25-4/282-287.htm 
  3. Smith, B. P. & Babos, M. (2022). Sildenafil. StatPearls. Retrieved on Aug. 14, 2022 from https://www.ncbi.nlm.nih.gov/books/NBK558978/  
  4. Sooriyamoorthy, T. & Leslie, S. W. (2022).  Erectile dysfunction. StatPearls. Retrieved on Aug. 14, 2022 from https://www.ncbi.nlm.nih.gov/books/NBK562253/ 
  5. Zucchi, A., Costantini, E., Scroppo, F. I., 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/