How Long Does it Take for Sildenafil to Take Effect?

Published February 5th, 2021 by Chris Riley
Fact Checked by
Camille Freking
Medically Reviewed:
Gerardo Sison
Updated Date: Jun 14th, 2022

Erectile dysfunction can be embarrassing and frustrating, which means that while many men want to get treatment for the condition, they often hesitate to pay a visit to the doctor’s office to discuss their symptoms.

Prescription medications like sildenafil, the generic form of brand name Viagra, offer an effective treatment option for erectile dysfunction, but they can be expensive.

Online telehealth companies are now making it easier than ever to obtain both professional medical advice as well as a prescription for sildenafil without a trip to the doctor’s office, but you might still have questions.

How long does it take for sildenafil to take effect and how long does sildenafil last?

What is erectile dysfunction and what causes it?

Erectile dysfunction is an incredibly common medical condition. Also known as male impotence, erectile dysfunction occurs when blood flow to the penis is limited by the blood vessels, which interferes with sexual stimulation, and can cause a man to be unable to get an erection or keep an erection that is hard enough for sexual activity. 

Erectile dysfunction can occur as a result of many factors, but among the most common are physical health conditions that commonly result from an unhealthy lifestyle, including: atherosclerosis (clogged arteries), high blood pressure, high cholesterol, diabetes, and obesity. 

Even in men who do not have these medical conditions, lifestyle can also influence erectile dysfunction's underlying causes.

Alcohol abuse, smoking, illegal drug use, side effects of other prescription medications (including those used to treat high blood pressure, heart disease, and depression), and side effects of over-the-counter medications such as antihistamines and Sudafed all have the potential to diminish the body’s ability to get and keep an erection.

Psychological factors such as depression, stress, and anxiety can also contribute to erectile dysfunction.  

How does sildenafil treat erectile dysfunction?

Sildenafil citrate belongs to a drug class called phosphodiesterase-5 (PDE-5) inhibitors. PDE-5 inhibitors act on an enzyme called PDE-5, which breaks down a chemical called cGMP.

In the first phase of an erection, cGMP relaxes the tissues and muscles of the penis, allowing blood to flow in. The relaxation of the muscles traps the blood flow, which causes an erection to occur.

As the PDE-5 starts to break down cGMP, blood flows out of the penis and the erection ends. 

In some men, this occurs prematurely or stops the erection from happening at all. Sildenafil works by blocking the action of PDE-5 and preventing it from breaking down the cGMP.

This keeps the muscles of the penis relaxed and engorged with blood, helping to keep the penis erect.

Men must be sexually aroused in order to have an erection, so there is no risk of experiencing an unwanted erection when taking sildenafil, and sildenafil has even been shown to help treat low level priapism in some patients. 

How long does it take for sildenafil to take effect?

Sildenafil is taken as a treatment of erectile dysfunction on an as-needed basis in advance of anticipated sexual activity, so knowing how long it takes for sildenafil to take effect is important.

Compared to slower acting erectile dysfunction medications, like Cialis (tadalafil), and faster acting medications like Levitra (vardenafil) and Stendra (avanafil), sildenafil falls squarely in the middle in terms of the amount of time it takes the drug to start working. 

Most men find that sildenafil starts to take effect within approximately 30 to 60 minutes, but it may take up to two hours for some individuals to feel the full effects of the medication.

Other factors, such as food you may have recently eaten, can also impact the amount of time it takes sildenafil to take effect.

Taking the medication with or in close proximity to a high fat meal can cause sildenafil to take longer to take effect, and the medication can also be less effective. 

If you’re especially concerned about making sure the medication works to its maximum effectiveness, don’t eat fatty foods such as steak, burgers, and lasagna for several hours before you take your pill, even if it means taking it on an empty stomach. 

How long does sildenafil last?

The marketing materials and literature indicate that sildenafil's duration of action is up to four hours.

While this is true for some individuals, many people find that the effects of the prescription drug start to subside after two to three hours, while others experience the effects of sildenafil for five hours or more depending on the dosage taken. 

No matter how recently you have taken sildenafil or what dose you take, the medication does not have an effect on the amount of time it takes to achieve orgasm.

Depending on the dosage and the timing of the medication dose, some men are able to achieve more than one erection with one dose of sildenafil.

However, this varies from person to person.  

How long does sildenafil stay in my system?

Sildenafil takes effect for most people within 30 to 60 minutes, but it wears off relatively quickly.

The effects of a typical dose of 25 mg or 50 mg subside for most people after two to three hours, although some people will take up to six hours to fully process the medication.

Higher doses of sildenafil, such as 100 mg, can take up to eight hours to fully leave the body. 

A number of different factors influence how long sildenafil stays in your system.

What factors determine how long sildenafil lasts?

There are a number of different factors that impact how long sildenafil lasts in your body, including things like the dose of the medication that you take, your age, your diet, alcohol intake, medications consumed, overall health, and psychological state.

Factors influencing the length of time sildenafil lasts vary from person to person but include:

  • Dosage: The lower the recommended dose of sildenafil you take, the more quickly the body is able to metabolize and eliminate the dose. Therefore, lower dosages of sildenafil, such as 20 or 40 mg doses, will leave the body more quickly than the 80 mg or 100 mg doses. Patients should take only the dosage advised by their doctor based on their medical history. 
  • Age: The older you are, the longer sildenafil will stay in your system, as older people process the medication more slowly. Sildenafil works noticeably longer for men over the age of 65 for this reason. 
  • Diet: We’ve already discussed that eating high-fat foods can cause sildenafil to take effect more slowly. While this is true, digesting high fat foods also slows the body’s metabolism of the drug, meaning that it stays in the body longer after eating a high fat meal. 
  • Alcohol intake: Alcohol consumption also influences the amount of time that sildenafil stays in the body. Alcohol is a depressant that decreases the amount of blood flowing to the penis, making the medication less effective. Sildenafil also lasts for less time when alcohol is in your system. 
  • Medications: Sildenafil can interact in a dangerous manner with the active ingredients of certain medications, including nitrates taken for chest pain (angina), causing potentially life-threatening serious side effects (though sildenafil is generally not dangerous for heart problems themselves, like history of heart attack). This is one of the main reasons why sildenafil is available by prescription only. Certain other medications also interact with sildenafil and increase its elimination time. Other drugs, including antibiotics like erythromycin, clarithromycin, and ciprofloxacin, can cause sildenafil to be eliminated from your system more quickly.  
  • Overall health: As noted previously, erectile dysfunction is often at least partially influenced by certain health conditions, including diabetes, multiple sclerosis, and heart conditions like atherosclerosis. In addition to causing erectile dysfunction, these health conditions are also known to reduce the effectiveness of sildenafil and increase the rate at which the medication is eliminated from the body. Some health conditions, such as kidney disease or poor kidney function, can extend the life cycle of the drug by slowing the rate at which it is metabolized.  
  • Psychological state: Erectile dysfunction is heavily influenced by your psychological state, and the effectiveness of sildenafil and the length of time that it lasts can also be impacted by your mental state.  Anxiety, depression, and stress can all negatively impact your body’s response to sildenafil.


Sildenafil is a relatively fast-acting medication that takes effect for most men within 30 to 60 minutes of consumption.

Things like consumption of a high-fat meal prior to taking the medication can slow absorption of the medication. 

Although sildenafil is only available with a prescription, telehealth services such as Hims, RexMd, BlueChew, and HealthyMale offer a way for men to connect virtually with a licensed healthcare provider in their state that can perform a consultation and determine if a prescription like sildenafil is appropriate for their use.

These sites also offer savings on sildenafil compared to traditional brick and mortar pharmacies.


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