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How does Viagra work and how long does it last?

Many men suffer from erectile dysfunction. Viagra and other ED medications can help.

What is Viagra | How does Viagra work | How long does Viagra last | Dosage | Warnings | Interactions | How do you know if you need Viagra | Side effects | Alternatives

Taking Viagra for the first time often sparks a series of questions. How does Viagra work? What can I expect? How long does Viagra last? What kind of side effects are normal and require medical attention? Here are answers to some frequently asked questions about the little blue pill. 

What is Viagra?

Viagra (sildenafil) is a prescription drug used to treat erectile dysfunction (ED) in men. Viagra can’t cure ED or increase sexual desire, but it can help relax muscles and increase blood flow to cause an erection. Viagra (manufactured by Pfizer) is a brand name for the generic medication sildenafil citrate. The U.S. Food and Drug Administration (FDA) has approved it to treat sexual impotence, but sildenafil may also treat pulmonary arterial hypertension. Viagra is a vasodilator that is only available by prescription. You cannot purchase Viagra over the counter in the U.S. 

How does Viagra work?

Viagra works by relaxing muscles in blood vessel walls to help increase blood flow to the penis, making it easier to get and maintain an erection. Viagra is only effective if there is sexual stimulation, such as that occurring during sexual intercourse. When stimulation first happens, Viagra helps increase blood flow to the penis and then works to help maintain an erection. 

According to the Boston University School of Sexual Medicine, erectile dysfunction affects up to 52% of men between the ages of 40-70, many of whom turn to erectile dysfunction medications to help with their symptoms. Viagra is a type of erectile dysfunction drug called a phosphodiesterase 5 inhibitor. PDE5 inhibitors keep a particular enzyme called phosphodiesterase type-5 (PDE5) from acting too quickly. If PDE5 acts slower, then a substance that’s responsible for relaxing muscles and widening blood vessels can do its job. 

Viagra will not be as effective for people with certain conditions. Those who are sick, fatigued, or intoxicated may not see full benefits from taking Viagra. Alcohol can worsen the side effects of viagra and potentially make erectile dysfunction worse. 

How quickly does Viagra work?

Viagra should be taken on an empty stomach about one hour before sex. The medication will start working within 30-60 minutes, but sexual stimulation is needed for Viagra to cause an erection. “Some patients experience the effects of Viagra within 20-30 minutes after taking the medication,” says Amber Williams, PharmD, a compounding pharmacist at Family Pharmacy in Sarasota. “However, if the dose is taken with a high-fat meal, the peak response may be delayed for up to 60 minutes. In most patients, the effects of Viagra will last for up to two hours. A duration of two hours or less indicates that an appropriate dose was taken. If the duration is greater than four hours, medical attention should be sought out immediately to avoid damaging effects on the tissues.” 

How long does Viagra last?

The amount of time that Viagra will last depends on many factors. Dosage, age, and overall health are just some of the factors that can impact how well Viagra works and lasts for someone. A smaller dosage of Viagra means that the drug won’t last as long, and for older adults, taking a lower dosage is recommended. 

Viagra is taken before sexual activity, as it takes time for Viagra to absorb into the bloodstream. It’s unlikely that Viagra will make you last longer in bed. However, some men may experience multiple erections while Viagra is in their system. Once it starts working, Viagra typically lasts for up to four or five hours. If you experience an erection that lasts longer than this (priapism) or is painful, it may be time to seek medical advice. 

Viagra dosage

The average dose of Viagra is 25-100 mg, taken 30 to 60 minutes or up to four hours before sexual activity. For adults over the age of 65, the recommended dose is 25 mg. Many older adults have slower metabolisms, which means that a lower dose may last longer for them in comparison to a younger person taking a small dose. 

Does Viagra make you last longer?

It is unlikely that Viagra will make you last longer. However, it can help those who experience premature ejaculation. Viagra also won’t necessarily help you recover faster after an orgasm. This recovery time is known as the refractory period and varies for each individual. Some men can have several erections while taking Viagra, but this will depend on their metabolism. Consuming alcohol while taking Viagra can make the medication less effective by decreasing blood flow to the penis. 

Viagra warnings

For people with certain medical conditions, Viagra might not last as long. Feelings of anxiety, depression, or nervousness often cause Viagra not to last as long or be as effective. Having a heart problem, heart disease, diabetes, or other nervous system problems can also cause Viagra not to last as long.

Viagra is not FDA indicated for use in females or pediatric patients. Viagra should also not be used in men that were advised to abstain from sexual activity due to underlying cardiovascular concerns. Use of Viagra is contraindicated in those taking nitrates or guanylate cyclase stimulators (riociguat). 

Viagra drug interactions

Certain medications may interact negatively with Viagra and interfere with its effectiveness. 

  • Alpha blockers: when used with Viagra, it can cause hypotension (low blood pressure); alpha blockers include alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), tamsulosin (Flomax), and terazosin (Hytrin); amlodipine (Norvasc)
  • Certain antifungals: can cause an increase in the amount of Viagra in the bloodstream, possibly leading to toxicity; these antifungals include itraconazole (Sporanox) and ketoconazole (Nizoral)
  • Nitrates: can cause increased hypotensive effect (blood pressure to drop too low); commonly used nitrates that can interact with Viagra include nitroglycerin (Nitrostat), isosorbide dinitrate, isosorbide mononitrate (Imdur), erythrityl tetranitrate, sodium nitroprusside (Nitropress), amyl nitrate and butyl nitrate (street drugs called “poppers”)
  • Beta blockers: can cause hypotension (low blood pressure); beta blockers include atenolol (Tenormin), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), propranolol (Inderal)
  • Erythromycin causes increased amount of Viagra, which could lead to toxicity
  • HIV protease inhibitors: these medications can cause slowed metabolism of Viagra, causing increased levels in the body and possible toxicity; these medications include atazanavir (Reyataz, also in Evotaz), darunavir (Prezista, also in Prezcobix), fosamprenavir (Lexiva), indinavir (Crixivan), lopinavir (in Kaletra), nelfinavir (Viracept), ritonavir (Norvir, in Kaletra), saquinavir (Invirase), tipranavir (Aptivus)

Talking with your healthcare provider is the best way to determine if Viagra will cause any drug interactions.

How do you know if you need Viagra?

Knowing when to speak to a doctor about getting Viagra can be challenging. Having trouble getting an erection doesn’t necessarily mean that you need to take Viagra. Viagra won’t cure erectile dysfunction, so it’s essential to look at potential underlying causes of impotence. 

Some men might not be able to get or maintain an erection for psychological reasons. If you don’t have a desire to have sex with your partner, this could be causing your ED. Talking with a counselor individually or seeing a therapist with your sexual partner could help with any underlying psychological issues that may be present. 

The best way to know if you will benefit from taking an erectile dysfunction medication like Viagra is to consult your healthcare provider. They can perform a physical examination and rule out medical conditions that may be causing ED, such as diabetes, high cholesterol, or high blood pressure. If you have no underlying psychological or health issues and have trouble getting and maintaining an erection that’s hard enough for sex, you may benefit from taking Viagra. 

Once you’ve talked with a healthcare provider, he or she may give you a prescription for Viagra. “Sildenafil is available online through validated telemedicine sites that connect you to licensed doctors,” says Dr. Williams. “These doctors will conduct an online visit and review your current health status to determine if sildenafil is an option for you. If you are a good candidate, your prescription may be shipped to you conveniently.” 

Even though Viagra is available for purchase online, it’s one of the most counterfeited drugs in the world. Some counterfeit pills contain printer ink, antibiotics, and even amphetamines. You can avoid buying fake Viagra online by getting a valid prescription and purchasing from a U.S.-based pharmacy that’s accredited by the Verified Internet Pharmacy Practice Sites. 

There are other prescription medications besides Viagra that treat erectile dysfunction. If you aren’t getting the results you want, it may be time to talk to your healthcare provider about other treatment options. 

Cialis (tadalafil) and Levitra (vardenafil) can also treat ED. The active ingredient that’s in generic Viagra, sildenafil citrate, is also in the medication Revatio. Revatio (sildenafil) is used to treat pulmonary arterial hypertension (PAH), a condition where blood pressure in the lungs is too high.

Viagra side effects

As with any medication, there is always the potential for side effects. The following list of side effects is not comprehensive. Speaking with a healthcare provider is the best way to determine if Viagra is the right medication for you. Here’s a list of some of the most common side effects that may result from taking Viagra: 

  • Flushing
  • Lightheadedness
  • Headache
  • Back pain
  • A runny or stuffy nose 
  • Indigestion 

Serious side effects

Although it’s rare, Viagra can sometimes cause serious side effects. If you experience a sudden loss of vision or hearing, you should stop taking Viagra and contact your healthcare provider immediately. If taking Viagra causes you to have an erection that’s painful and lasts more than four hours, you should also contact your healthcare provider. If you experience chest pain after taking Viagra at the onset of sexual activity, you should stop immediately. In extreme cases, Viagra has caused heart attacks in people with prior heart conditions. 

Drinking excessive amounts of alcohol while taking Viagra can significantly increase the risk of experiencing any of the side effects listed above. Talking with a healthcare provider is the best way to get a comprehensive list of side effects and to learn more about whether or not taking Viagra is right for you. 

Viagra alternatives

There are several alternatives to Viagra on the market. However, some are prescribed for different uses and some have different modes of action compared to Viagra. 

  • Revatio is an alternative to Viagra, as they are both formulated with the same generic ingredient, sildenafil. However, they are dosed differently and Revatio is only FDA approved for use in pulmonary arterial hypertension. 
  • Cialis (tadalafil) is also used for erectile dysfunction, as well as benign prostatic hyperplasia. They differ in that Cialis can also be used daily as needed, but its effects last much longer than Viagra, up to 36 hours. 
  • Levitra (vardenafil), while also used to treat erectile dysfunction, has been shown to be more potent in clinical studies than Viagra. 

Stendra is also used to treat ED, but in clinical studies it has been shown to cause fewer side effects as well as fewer interactions with other drugs. It can also be taken in a larger dose as soon as 15 minutes before sexual activity.