How Long Does Viagra® (Sildenafil) Last?

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? If you stop for dessert, will the effects wear off? How long does Viagra (sildenafil) last? These are fair questions 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. But getting the timing right is key.

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 how well it works, including what you eat and when.

Keep reading to find out how long sildenafil and Viagra last in your system and learn how quickly (and how well) these medications work for the treatment of erectile dysfunction.

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 may have 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. 

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.

How Long Does Sildenafil Last?

Like the branded version, sildenafil usually lasts for approximately four hours. 

In one study published in the British Journal of Clinical Pharmacology, men with ED who used sildenafil 100mg were able to attain an “adequate” erection four hours later. These findings indicate that even four hours after taking sildenafil, there's still enough of it in the body to support satisfactory erections. This aligns with sildenafil's half-life of three to five hours. This timeframe offers a practical and convenient window for most couples to engage in sexual activity.

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 intercourse.

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. 

Does Dosage Impact How Long Viagra and Sildenafil Last?

Viagra and generic sildenafil typically come in three standard doses: 25mg, 50mg, and 100mg. Most guys start off with a 50mg 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.

Taking a higher dose of Viagra or sildenafil isn’t a good strategy to make you last any longer. It can cause dangerously low blood pressure and increase your risk of side effects, so don’t try overdosing on purpose. 

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 how long sildenafil lasts.

• 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 seek medical advice. 

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

Because the half-life of Viagra isn’t something you can change, there’s no simple way to make this medication last 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. 

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 of sildenafil and Viagra 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.

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, but this doesn’t mean it leaves your system right away. After four hours, the amount of sildenafil in your bloodstream decreases by about 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. 

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.

These prescription medications are called phosphodiesterase type 5 inhibitors. They inhibit 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. 

Here’s how these Viagra alternatives compare:

• Cialis: 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: 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: 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.

If you want to know more about Viagra and PDE5 inhibitors, check out our blog on how Viagra works.

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

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

• 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.