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.
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.
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.
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:
Several factors influence how long Viagra works for:
Older men tend to metabolise Viagra more slowly, meaning its effects may last longer.
High-fat meals can delay absorption and shorten effectiveness.
Alcohol can reduce blood flow and make Viagra less effective.
Further reading: Viagra and Alcohol
Higher doses (e.g.100mg) may last longer than lower doses, but they also increase the risk of side effects.
Conditions such as diabetes, heart disease, or nerve damage can affect how well Viagra works.
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.
Stress, anxiety, and depression can all reduce sexual arousal, which may make Viagra less effective.
To get the most out of your treatment:
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.
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.
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.
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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