Table of ContentsView AllTable of ContentsHow Viagra WorksOnset of ActionDuration of ActionDrug ClearanceSide EffectsAlternatives
Table of ContentsView All
View All
Table of Contents
How Viagra Works
Onset of Action
Duration of Action
Drug Clearance
Side Effects
Alternatives
Viagra (sildenafil) is an oral drug used to treaterectile dysfunction (ED). Viagra can last for about four hours or more in some people and should be taken 30 minutes to an hour before sexual activity.
ED affects around one in four people with penises in the United States—or roughly 30 million people—with the incidence increasing to one in three after the age of 55.
Viagra belongs to a class of drugs calledPDE-5 inhibitorsthat help stimulate the dilation (widening) of blood vessels in thepenis, allowing it to engorge more fully with blood to achieve and sustain anerectionsuitable for sex.
This article explains how Viagra works, how long the effects last, and the various factors that affect how effectively the drug works.
Getty Image / nito100.
How Does Viagra Work?
How Long Does Viagra Take to Start Working?
Viagra takes about an hour to work, although some males are able to achieve an erection within 30 minutes of a dose.
Viagra reaches its maximum concentration in the bloodstream within one to two hours. This is the time frame during which Viagra exerts its optimal effects. After two to three hours, the effects start to diminish.
Viagra does not work in the absence of sexual stimulation or interest. You need to besexually arousedin order to reap the benefits of treatment.For best results, take Viagra one hour before sexual activity or foreplay but no longer than four hours beforehand.
How Long Does Viagra Last?
Viagra usually lasts for around four hours, although the effect may be longer lasting in some people. Even so, try not to take Viagra more than four hours before sexual activity just to be safe.
There are several reasons why Viagra may be longer lasting in some people:
Will Viagra Keep Me Erect After I Ejaculate?
While Viagra will probably not keep you erect after you ejaculate, it may help decrease therefractory period. This is the time afterejaculationwhen you have difficulty getting an erection again.
The refractory period may be as short as a few minutes in younger people and as long as a few hours or days in older adults.
How Long Does It Take for Viagra to Leave the System?
This does not mean that Viagra will work for 16 to 20 hours. While there may still be some drug left in your bloodstream, the amount will not be bioactive (able to exert a biological or physiological response).
Factors That Negatively Affect Viagra
There are certain factors that can affect how well Viagra is absorbed into the bloodstream. The drop in drug concentration can reduce its ability to work effectively.
These factors include:
Viagra Side Effects
As with all drugs, Viagra can cause side effects. The side effects tend to be relatively mild, although some people may experience them more profoundly than others.
Common side effects of Viagra include:
An uncommon but potentially serious side effect ispriapismin which an erection lasts six hours or more, causing pain and potentially long-term tissue damage. Priapism is considered a medical emergency in need of immediate treatment.
Viagra and Ejaculation
The effects of Viagra on ejaculation are unclear. One study has shown that Viagra may improve premature ejaculation, meaning you will last longer during sex. With that said, it is unclear if the improvement is due to Viagra or the fact that the drug reducesperformance anxietywhich contributes to premature ejaculation.
Is Viagra Safe for Females?
Females experiencing low libido or other sexual dysfunction should speak with their gynecologist or healthcare provider about treatments that may help.
Alternatives to Viagra
PDE-5 inhibitors are the most common drugs used to treat erectile dysfunction. Viagra was the first PDE-5 inhibitor introduced in 1998, but there are others you can turn to.
Among them:
Other treatments that can help with ED includepenile pumps,penile implants, psychotherapy, andalprostadil injections.
Summary
Common side effects include headache, flushing, indigestion, blue vision, and stuffy nose.
16 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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