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How long does it take Viagra to kick in?

Here’s what you need to know about how the erectile dysfunction drug works
Alex Halperin
By | Jun. 6, 2023 Medically reviewed by Gerardo Sison, Pharm.D.
Little blue pill, aka Viagra, on purple background

Key takeaways

  • Viagra is recommended to be taken about one hour before sexual activity, with its effects lasting up to four hours and beginning in less than 30 minutes for most men.

  • Consuming Viagra on an empty stomach or two hours after a meal enhances its effectiveness while avoiding excessive alcohol and grapefruit can prevent negative interactions.

  • Viagra, a PDE5 inhibitor, increases blood flow to the penis to help achieve and maintain an erection, but it requires sexual arousal to work and does not directly affect ejaculation times.

  • Factors such as overall health, dosage, age, food, and alcohol consumption, and smoking can influence how long Viagra’s effects last and its overall effectiveness.

In this article:

Since its FDA approval in 1998, Viagra (sildenafil citrate) has become a well-known prescription medication for treating erectile dysfunction (ED), affecting about 30 million men in the U.S. alone. But to ensure it works, it’s not as simple as popping the little blue pill. For best results, timing may be everything. Read on to learn when to take Viagra, how long it takes Viagra to work, and more need-to-know tips. 

How long does it take for Viagra to work?

Viagra is recommended to be taken about one hour before you plan to have sex and lasts for around four hours. So it’s crucial to time doses wisely. For example, don’t take it in the morning if you expect to have sex at night.     

For most men, Viagra typically begins working in less than 30 minutes but could take up to an hour. While Viagra’s effects usually start to kick in within the first 30 minutes, the drug may not reach peak levels in the blood until two hours after administration. This means you might not feel its full effects until two hours after taking it. You’ll know it’s working when you find that when you’re aroused and during sexual stimulations, you’re able to achieve and maintain an erection.

To achieve the optimal effects of Viagra, plan your dose to avoid consuming too much food and alcohol beforehand. “The best way to take Viagra is either one hour before sex on an empty stomach or two hours after a meal to avoid a delay in effectiveness,” says Barrett Cowan, MD, a reproductive urologist at Posterity Health in Greenwood Village, Colorado. And since alcohol worsens erectile function, keep the drinks to a minimum to avoid negating Viagra’s effects. 

Because most erectile dysfunction is caused by impaired blood flow to the penis, Viagra works to increase penile blood flow. It was the first of a class of drugs known as phosphodiesterase 5 (PDE5) inhibitors designed to help men achieve and maintain an erection by blocking the PDE5 enzyme, thereby relaxing the blood vessel walls and increasing blood flow to the penis. Viagra doesn’t cause an erection automatically, however. You must be sexually aroused for it to work.

Viagra and other PDE5 inhibitors, such as Cialis (tadalafil) and Levitra (vardenafil), can also be used for ED caused by psychological reasons. However, they won’t target the underlying psychological causes, as they work to enhance blood flow to the penis. 

How long does Viagra last?

Viagra’s effects typically last up to four hours, sometimes more, depending on the dose and the individual. However, this doesn’t mean that a sustained erection will last for this time (an erection lasting more than four hours, known as priapism, is a rare potential side effect that can cause lasting damage—seek medical attention if this happens.). Instead, it means that the increased blood flow to your penis should help you to achieve and maintain an erection when you’re sexually aroused within a three to four-hour window. 

While Viagra can help you produce an erection, it doesn’t make you last longer or affect the amount of time before you ejaculate. If you suffer from premature ejaculation, Viagra won’t change your sensitivity to extend the time before ejaculation. “The circulatory system produces erections,” says Dr. Brandeis, “while orgasm is a function of sensitivity and the nervous system.”

However, Viagra may shorten the refractory period—the interval after ejaculation before the penis can become erect again—which may enable users to prolong their sexual activity throughout the medicine’s window of effectiveness.

What factors affect how long Viagra lasts?

Viagra works for most men most of the time. However, several factors may affect the duration and effects of Viagra. The following six factors may slow Viagra’s absorption and reduce its concentration in the body, which may make it less effective or shorter lasting. 

Overall health

Because ED is typically a symptom of problems with circulation or other health conditions, such as heart disease and diabetes, the underlying cause of your ED can affect how well you respond to it. Being in good health may make Viagra more effective at producing a strong and longer-lasting erection. 

Dosage

The amount of Viagra you take may affect how long it remains in your system. For instance, a 100 mg dose of Viagra may make the effects last longer, but it may not be as safe for some as a 25 mg or 50 mg dose. In addition, it won’t necessarily double or extend the effect duration in a linear manner. Each person’s body may process the medication differently.

Age 

In general, Viagra works longer for older men because it tends to take longer for their bodies to metabolize the medicine. While that may sound like a bonus, having Viagra in your system for longer increases the risk of adverse side effects. Dr. Cowan says that he typically prescribes a lower dose to older patients, who also are more likely to have reduced kidney and liver function.  

Food and alcohol consumption 

Taking Viagra after eating, especially fatty foods, can slow down the medicine’s effects. And while there’s nothing wrong with having a glass of wine if it helps to set the mood,  alcohol use is a common cause of ED, so drinking alcohol while taking Viagra is counterproductive. Plus,  heavy drinking has been shown to increase some of Viagra’s side effects, including headaches, facial flushing, dizziness, and even chest constriction.

Being a smoker  

Smoking, which causes blood vessels to lose their elasticity over time, can slow how long Viagra takes to start working and weaken its effects.

Tips for taking Viagra

While it’s always important to follow the guidelines provided by your healthcare provider and pharmacist, these additional tips can help ensure you have the best and safest experience with Viagra.

1. Take it on an empty stomach, or two hours after a meal

Viagra works faster and often better on an empty stomach. Of course, if you’re concerned about having enough energy to have sex, it might be a good idea to eat something low in fat and wait a couple of hours. Fatty foods like cheeseburgers and french fries can delay Viagra’s effects.

2. Watch your alcohol intake

Many people combine sex and alcohol use. The good news is it’s generally considered safe to have a drink with Viagra. However, excessive alcohol consumption is associated with dulled sexual function, and studies have shown it can increase the chance of side effects, including dizziness and chest discomfort.

3. Avoid grapefruit. 

Viagra can also interact with grapefruits and grapefruit juice. It has been shown to increase the levels of Viagra in your body, which can increase the risk of side effects. If you want to eat grapefruit products, speak to your healthcare provider about whether a lower dose of Viagra is an option.

For most men, the 50 mg pill is the recommended dosage. Lower dosages may be more appropriate for older people or those with existing health conditions. When 50 mg doesn’t work, doctors may prescribe the 100 mg pill. Taking more than 100 mg doesn’t necessarily help achieve a strong erection; plus, it increases the risk of side effects.

5. Be aware of the side effects

Common side effects of Viagra include headaches, flushing, congestion or runny nose, dizziness, upset stomach, blue-green-tinged vision, blurred vision, and muscle aches. The blue-green-tinged vision occurs in fewer than 5% of patients, as Viagra can exert inhibitory action against an enzyme only present in the eye’s rod and cone photoreceptors. Be sure to talk to your healthcare provider about any side effects you experience.

One rare but dangerous side effect is having an erection that lasts more than four hours. This condition, called priapism, can cause lasting damage. Seek medical attention immediately if this happens.

Why you should talk to your healthcare provider about ED drugs

If you have erectile dysfunction, seek medical advice from a healthcare provider about your condition before taking Viagra. The condition could be a symptom of an underlying health condition such as heart disease of kidney disease.

“ED is an indication that your circulatory system isn’t working as well as it should be,” says Judson Brandeis, MD, a urologist practicing in San Ramon, California, and author of The 21st Century Man. He warns that while taking Viagra will help most patients achieve an erection, it could also make them miss this early warning sign of cardiovascular disease.

People with cardiovascular disease generally need to follow precautions when taking Viagra with certain heart medications. Viagra has been reported to cause heart attacks, especially in people who have had a recent heart attack in the past six months. 

However, some studies show that PDE5 inhibitors may have protective effects on the heart. For example, a recent large study found that PDE5 inhibitors may reduce the chance of dying from heart disease. Over the 14-year study, men with ED who took PDE5-inhibitors had a 13% lower incidence of heart attacks than those who didn’t, along with a 25% lower death rate. It’s important to consult a healthcare provider before taking Viagra if you have a history of heart problems.

Take the right ED drug for you

Viagra, which Pfizer developed, was the first PDE5-inhibitor used to treat erectile dysfunction. Today, there are other PDE5-inhibitors—including Cialis (tadalafil) and Levitra (vardenafil)— on the market as well.

Your healthcare provider will help you choose the best ED treatment for you by reviewing several factors, including any health conditions you may have. The main difference between Viagra and Cialis, for example, is that Cialis typically lasts longer—it can help you achieve an erection for up to 36 hours after ingestion. Cialis can also be taken in a smaller dosage daily to help produce an erection when you’re ready for it. 

If you prefer to eat before sex, Cialis may be a better option than Viagra since it is not known to be affected by fatty foods. Cialis also doubles as a treatment for an enlarged prostate.  

Levitra can start working slightly faster than Viagra: In some, Levitra can work in as little as 15 minutes. Or, if you have tried Viagra and had unpleasant side effects or didn’t feel that it worked well, Levitra could be a good alternative.

Be aware of drug interactions.

Always tell your healthcare provider about all other medicines you take before taking Viagra. They can help determine if the little blue pill is safe for you. The following medications can cause adverse reactions with Viagra:

Additionally, Viagra should not be taken with “poppers,” says Dr. Cowan. Poppers are over-the-counter products used recreationally, sometimes in a sexual context. They contain chemicals similar to nitrates and can lead to a dangerous drop in blood pressure when combined with Viagra.

How to save on Viagra 

Although the drug is widely prescribed, Viagra isn’t cheap. A single higher dose 100 mg pill can cost more than $100. Luckily, there are several ways to save.

  • Find a medication on your formulary. Not all insurers cover Viagra, but your health insurance provider may cover another brand of ED medication. Check your insurance formulary to find out. 
  • Go generic: You’ll pay a fraction of the prices for the same active ingredients in generic ED medications like sildenafil, the generic version of Viagra. However, since ED drugs are some of the most counterfeited in the world, it’s essential to make sure that your pills come from a reputable pharmacy in the U.S. If you use an internet pharmacy, check the website for the VIPPS (Verified Internet Pharmacy Practice Sites) seal.  
  • Buy in bulk: Like most things, pharmaceuticals often cost less when purchased in larger quantities. Look for a 90-day supply as opposed to a 30-day supply.
  • Use SingleCare coupons: SingleCare coupons can help you locate the lowest-priced medications in your area. Use the Viagra coupon below to find a reduced price, such as $8.54 for 30, 100 mg generic Viagra (sildenafil) pills, at a participating pharmacy near you.

Viagra coupons