Viagra (Sildenafil) is one of the most commonly prescribed treatments for erectile dysfunction.

Many men want to know how long the effects last, how quickly it works, and what factors can influence its duration.

This guide explains everything you need to know so you can get the best results from your medication.

How long does Viagra last for?

On average, Viagra lasts for 4-5 hours. This is the window in which the medication helps you achieve and maintain an erection, when you are sexually aroused.

However, the exact duration can vary depending on your age, metabolism, health, and whether you have taken Viagra correctly.

You will not have an erection for the full duration, Viagra simply increases blood flow to the penis, making it easier to get and maintain an erection during this 4-5 hour window.

How long does Viagra stay in your system?

Although the effects last around 4-5 hours, Viagra can remain in your body for up to 24 hours.

After 4-5 hours, the amount of Viagra left in your system is too low to have any noticeable effect.

How long does Viagra take to work?

Viagra usually takes 30-60 minutes to start working.

Some men may find that it can work in as little as 12 minutes.

However, Viagra reaches its peak concentration in the blood after 60 minutes, which is when results are the best.

For best results:

  • Take it on an empty stomach: Heavy meals or high-fat foods can delay how quickly Viagra starts working.
  • Avoid alcohol: It can counteract the effects of alcohol and reduce sexual responsiveness
  • Allow time for sexual arousal: Viagra works best when sexual arousal is highest

What can affect how long Viagra lasts?

Several factors influence how long Viagra works for:

Age

Older men tend to metabolise Viagra more slowly, meaning its effects may last longer.

Food intake

High-fat meals can delay absorption and shorten effectiveness.

Alcohol

Alcohol can reduce blood flow and make Viagra less effective.

Further reading: Viagra and Alcohol

Dose

Higher doses (e.g.100mg) may last longer than lower doses, but they also increase the risk of side effects.

Health conditions

Conditions such as diabetes, heart disease, or nerve damage can affect how well Viagra works.

Medications

Certain medications, especially alpha-blockers, blood pressure medication, and nitrates, can interact with Viagra and effect how long it lasts. Always check with a healthcare professional before taking Viagra with any other medication.

State of mind

Stress, anxiety, and depression can all reduce sexual arousal, which may make Viagra less effective.

Important considerations

  • Sexual stimulation is required: Viagra won’t cause an erection on its own; it only works when you are sexually aroused.
  • Do not exceed one dose in 24 hours: Never take more than a single dose of Viagra within the same day.
  • Priapism warning: A rare but serious side effect is an erection lasting longer than four hours. If this happens, seek urgent medical attention.

How to make Viagra last longer

To get the most out of your treatment:

  • Timing: Take Viagra about 60 minutes before sexual activity. It can be taken up to 4 hours in advance, though effectiveness may decline over time.
  • Empty stomach: For faster, more reliable absorption, take it on an empty stomach or after a light, low-fat meal. Heavy or high-fat meals can delay its effects.
  • Avoid grapefruit juice: It can interfere with how Viagra is absorbed and increase the risk of side effects.
  • Limit alcohol: Too much alcohol can make it harder to get an erection and may heighten side effects like dizziness.
  • Correct dosage: Only take the dose prescribed (25mg, 50mg, or 100mg) and never exceed 100mg in 24 hours. If your current dose isn’t effective, speak to a healthcare professional.
  • Sexual stimulation required: Viagra only works when you are sexually aroused; it won’t cause an automatic erection.
  • Maintain a healthy lifestyle: Keeping a healthy weight and staying active can support better erectile function and improve treatment response.
  • Manage underlying conditions: Conditions like diabetes or high blood pressure can affect how well Viagra works, so proper management is important.

If Viagra isn’t lasting long enough or isn’t giving the desired effect, speak to a healthcare professional, an alternative medication or a change in dose may help.

Are there any alternatives that last longer than Viagra?

If you need a longer-lasting option, your doctor may recommend a different medication. For example, Tadalafil can remain effective for up to 36 hours, offering a wider window for more spontaneous sexual activity.

Always speak with a healthcare professional to find the most suitable treatment and dose for your needs.

Frequently asked questions

No, Viagra, Viagra Connect, and generic sildenafil all contain the same active ingredient (Sildenafil citrate) and work in the same way. They typically last 4-5 hours regardless of the brand. The main difference is branding and price, not duration or effectiveness.

An erection lasts only as long as you are sexually stimulated, and it should go down after ejaculation or when arousal stops.


  1. Eardley I. “Onset and duration of action of sildenafil for the treatment of erectile dysfunction.” British Journal of Clinical Pharmacology. 2002. (Accessed: 14 November 2025). From: https://pmc.ncbi.nlm.nih.gov/articles/PMC1874251/

Whilst all of our content is written and reviewed by healthcare professionals, it is not intended to be substituted for or used as medical advice. If you have any questions or concerns about your health, please speak to your doctor.

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