How Long Does Sildenafil Last and Related Queries

Sildenafil is the most common oral treatment for Erectile Dysfunction (ED) in men or Assigned Males at Birth (AMAB).

It helps you to get and hold an erection for satisfactory sexual intercourse. 

But how long does Sildenafil last after you have taken it?

This article will discuss the effectiveness of Sildenafil, its working, and more such questions. 

We will also talk about if taking two Sildenafil pills make you last longer in bed. 

How long does Sildenafil last

According to the Food and Drug Authority, Sildenafil may last up to four hours after taking it. 

This indicates that Sildenafil remains in your system for up to four hours after you swallow it. 

Sildenafil is the first FDA-approved medicine in the US to treat ED in men or AMAB. 

Let us discuss the duration, effectiveness, and working of Sildenafil in detail below.

How long will Sildenafil keep you hard

According to Medical News Today, Sildenafil may keep you hard for approximately four hours. 

It is because the half-life of Sildenafil is four hours. 

This means Sildenafil reduces to half after four hours of taking it. 

While you may still be able to get an erection until four hours, its strength diminishes. 

How long does Sildenafil stay in your system

Although Sildenafil’s effects diminish in four hours, the medicine might still be in your system. 

According to research, Sildenafil may take about 24 hours to eliminate from your body completely. 

You should take no more than one Sildenafil tablet in 24 hours. 

What is the peak time for Sildenafil

Usually, Sildenafil begins to show its effect about an hour after you take it. 

However, showing its full effects may take up to two hours. 

This means that Sildenafil will be most effective after two hours of taking it. 

After that time, the medicine’s effects begin to degrade. 

How does Sildenafil work

Sildenafil belongs to the class of medications known as Phosphodiesterase type 5 (PDE5) Inhibitors.

These medicines work by inhibiting the action of the PDE5 enzyme in the penis.

This PDE5 enzyme breaks down cGMP levels in the blood, turning the penis soft.

By inhibiting PDE5, Sildenafil relaxes the blood vessels in the penis.

This action allows more blood to flow through the penis.

An increased penile blood flow helps you in getting and maintaining an erection.

What factors affect the working of Sildenafil

Several factors affect how Sildenafil works, making it less effective. 

It may include your age, lifestyle habits, and your overall health. 

Let’s take a look at these factors and understand how they affect Sildenafil’s working. 


Age is the primary factor that affects your sexual health. 

Your metabolism turns deficient as you age, weakening your immune system.

A weak immune system builds up a tolerance to the medicine, affecting the erections. 

It is why older adults are more likely to experience side effects than younger individuals. 

Medicine Dosage

How long Sildenafil will last also depends on the strength of your medicine.

Taking a higher dose is likely to last longer than the lower strength. 

Lifestyle habits

Avoid alcoholSource: Africa's_Image
Avoid alcohol

According to a study in the Pharmaceutics journal, smoking delays the effects of Sildenafil. 

Consuming excessive alcohol or other drugs while taking Sildenafil might be risky. 

Quitting smoking, alcohol, and other substance abuse might deliver better results from Sildenafil.

Overall health

A person with no medical condition is likelier to experience better results using Sildenafil. 

Your current medicines might interact with or affect the way how Sildenafil works. 

If you have a medical history, it’s always best to speak to your doctor before taking Sildenafil.

Taking Alcohol with Sildenafil may intensify the medicine’s side effects.

Can taking two Sildenafil pills together make you last longer

No. Doubling the dose of Sildenafil might be risky and can result in an overdose. 

Sildenafil is a prescription medicine; you should not take more than your doctor recommends. 

Overdosing on Sildenafil may result in a few side effects that range from standard to rare. 

Some of the common side effects of Sildenafil are:

Heart problemsSource: natrot
Heart problem
  • Difficulty in breathing
  • Dizziness
  • Fatigue
  • Headache
  • Indigestion
  • Muscle/ body pain
  • Nausea

In rare cases, one may experience Priapism or allergic reactions. 


Sildenafil helps to get and keep erections, treating ED in men and AMAB.

But you should follow certain precautions while taking this medicine. 

Generally, Sildenafil may last up to four hours after its consumption. 

However, several other factors affect how long Sildenafil last in a person.

These include the individual’s age, lifestyle, and overall health.

Do not double the dose to enhance the effectiveness of the medicine. 

If case of any side effects, discuss them with your doctor.

Phosphodiesterase type 5 (PDE5) is an enzyme in the penis that turns the penis soft soon after ejaculation.
Cyclic Guanosine Monophosphate (cGMP) is a regulator that mediates the smoothening of penile muscles.
Priapism is the condition of a prolonged erection that lasts longer than four hours and is usually painful.

Frequently Asked Questions

How long does Sildenafil last before it expires?

According to Healthline, Sildenafil (Generic Viagra) has a shelf life of about two years. 
It means you can consume the medicine until two years after it is manufactured.

How to use Sildenafil for best results?

Take the Sildenafil tablet as recommended by your doctor. 

Take it 30 minutes to an hour before performing sexual intercourse. 

You can take it with or without food. But avoid taking oily or high-fat meals when taking Sildenafil.

How long does it take for Sildenafil to show results?

Sildenafil begins to work about 30 minutes to an hour after consumption. 

You may experience improvement in your erection after this time. 

However, it may take up to four hours for Sildenafil to show complete effects.

Is Viagra the same as Sildenafil?

Viagra is the brand name medication that contains Sildenafil as its active ingredient. 

In 1998, Pfizer got Sildenafil patented as a brand to treat Erectile Dysfunction in men.

Today, Sildenafil is available as Generic Viagra under various brand names.

How long will Sildenafil keep you hard?

Sildenafil might be effective up to four hours after consumption. 

The exact duration of the medicine depends on the individual’s health, lifestyle, and eating habits.

What is the best time to take Sildenafil?

You should take Sildenafil about an hour before involving in sexual activity. 

Sildenafil’s effects last up to four hours after you take the medicine.

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Janet Fudge is a highly skilled and experienced pharmacologist who serves as a contributing writer for With a strong academic background from a premier US University and a passion for helping others, Janet has become a trusted voice in the pharmaceutical world. After completing her Doctor of Pharmacy degree, Janet embarked on a successful career in the pharmaceutical industry, working with various clients, including hospitals, retail pharmacies, and drug manufacturers. Her in-depth knowledge of pharmacology and dedication to patient-centered care has led her to excel in her field. As a writer for, Janet uses her wealth of expertise to provide readers with accurate, reliable, and up-to-date information on various topics related to medicine and healthcare. Her engaging writing style and ability to break down complex topics into easily digestible content make her a valuable resource for healthcare professionals and the general public.