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What if Viagra Doesn’t Work?

Vicky Davis

Medically reviewed by Vicky Davis, FNP

Written by Our Editorial Team

Last updated 8/29/2022

Viagra®, which contains the active ingredient sildenafil, is one of the most popular medications for erectile dysfunction (ED).

It’s also occasionally used to treat other male sexual performance issues, including premature ejaculation (PE). Sildenafil, the active ingredient in Viagra, is also used to manage pulmonary arterial hypertension (PAH), a form of high blood pressure that can affect the lungs.

Used at a normal dose on an empty stomach, Viagra usually starts to work within one hour and makes getting and maintaining an erection easier.

However, Viagra and other ED medications aren’t 100 percent effective. In fact, some men who take Viagra still experience erectile dysfunction and other sexual performance issues even after using their medication. 

Most of the time, these issues are fixable, either by making changes to the way you use Viagra or identifying and treating other factors that may be contributing to your sexual function issues.

Below, we’ve explained why Viagra and other ED drugs, like Cialis® (tadalafil), sometimes don’t work as intended, as well as what you can do if you still find it difficult to get and stay hard after using Viagra. 

The Basics of Viagra for ED

Before we get into why Viagra sometimes doesn’t work for the treatment of erectile dysfunction, it’s important to go over how Viagra and similar medications actually work within your body.

Viagra belongs to a class of drugs referred to as PDE5 inhibitors, which work by increasing the flow of blood to certain parts of your body, including your penis.

Healthy erections are all about blood flow. When you feel aroused, your nervous system sends a signal to your corpora cavernosa -- a pair of elongated bodies of erectile tissue located inside your penis.

This causes the blood vessels that supply your penis to expand, allowing more blood to flow to the erectile tissue. As blood flows to your penis, the erectile tissue expands and becomes firm, creating an erection.

The enzyme phosphodiesterase 5 (PDE5) plays a key role in regulating blood flow through the blood vessels that supply your penis. Sildenafil inhibits the effects of PDE5, helping to open up your blood vessels and promote optimal blood circulation.

It’s worth noting that Viagra only affects blood flow, meaning it won’t have any effect on sexual arousal or desire.

Contrary to popular belief, Viagra also doesn’t cause spontaneous erections, or erections that occur without any sexual stimulation. Instead, it works solely by increasing blood flow, making the physical side of getting and maintaining an erection easier. 

Read our article on what Viagra does to your sexual experience for more details.

Why Viagra Doesn’t Always Work

Most of the time, Viagra works well as a treatment for erectile dysfunction. Most men who use Viagra and similar ED medications report positive results, including stronger erections and an increased sense of confidence in bed.

However, research shows that not all men with erectile dysfunction experience improvements after using Viagra.

For example, clinical trials of Viagra show improvements among 63 to 82 percent of men with erectile dysfunction, with men prescribed the 100mg dosage of Viagra most likely to report an improvement in their erections. 

There are several reasons Viagra and other ED drugs might not work effectively as treatments for erectile dysfunction. These include using Viagra incorrectly, taking a low dose of Viagra and using Viagra to treat ED that’s caused by something other than poor blood flow. 

We’ve discussed each of these potential causes below and explained what you can do to make getting and maintaining an erection easier.

You’re Not Using Viagra Correctly

Viagra needs to be taken correctly in order to treat erectile dysfunction effectively. When Viagra isn’t used properly, it might be less effective than normal, take longer to work or just not provide a noticeable improvement in your erections and sexual function.

To get the best results from Viagra, it’s recommended to:

  • Take Viagra on an empty stomach. Taking Viagra after finishing a large, high-fat meal may delay its absorption, preventing it from working properly when you have sex.
    If you normally take Viagra with food and notice that it isn’t working properly, try to take it on an empty stomach.

  • Wait an hour for Viagra to start working. Viagra can be used 30 minutes to four hours before sexual activity, but it typically works best when it’s taken one hour before the time that you plan to have sex.

  • Avoid taking Viagra too early. Unlike tadalafil, which can continue working for 36 hours per dose, Viagra becomes much less effective after four hours. Because of this, it’s best to avoid taking Viagra more than four hours before you plan to have sex.

  • Limit your consumption of alcohol. Drinking alcohol to excess can cause a temporary form of erectile dysfunction known as whiskey dick, which may reduce the effectiveness of medications like Viagra.
    Try to avoid drinking alcohol on nights you use Viagra. If you do drink, limit your alcohol consumption to one or two services. 

  • Avoid using recreational drugs. Some recreational drugs can cause weak erections and potentially make Viagra less effective. Avoid using recreational drugs, even if legal, while you’re using Viagra to treat ED. 

  • Make sure you’re sexually aroused. Viagra triggers an increase in blood flow to your penis, but it doesn’t have any effect on sexual arousal. Make sure that you’re truly in the mood for sex before using Viagra or other medication to treat erectile dysfunction. 

If you have any questions about using Viagra or other medication to treat ED, it’s always best to ask them to your healthcare provider. 

You’re Using a Low Dose of Viagra

Viagra and generic sildenafil come in several doses, with the total sildenafil content of each pill ranging from 20mg to a maximum dose of 100mg. 

If you’re using a lower dose of Viagra and find it isn’t fully effective at treating ED (or, it doesn’t seem to provide any improvement at all), consider talking to your doctor about moving up to a higher dose of the medication. 

Clinical trials of Viagra show that more men report improvements with a higher dose, such as 50mg or 100mg, than with a 20mg dosage.

An analysis of two studies published in the International Journal of General Medicine in 2013 also found that men with ED who used a 100mg dose of sildenafil showed better results than men who used a 50mg dose of sildenafil. 

If you think your dosage of Viagra is too low, it’s best to talk to your healthcare provider. They may adjust your Viagra dosage or suggest switching to a different ED medication. 

You’re Giving Up on Viagra Too Early

It’s quite common for Viagra not to work the first time you take it. Many people who use Viagra are nervous about the drug’s effects and anxious that it might not work as intended, increasing the risk of experiencing sexual performance anxiety

Before you give up on Viagra, try using it at least a few times. If it doesn’t work, consider talking to your doctor about switching to a higher dose. 

Often, Viagra will become more effective after a few tries as you become more comfortable with the medication and confident in its effects. 

Your ED is Caused by an Underlying Health Condition

Viagra is generally an effective treatment for ED. However, if you have erectile dysfunction that’s caused by an underlying health condition, such as diabetes or heart disease, Viagra may not be fully effective at restoring your ability to get and maintain an erection. 

Common physical causes of erectile dysfunction include heart disease, diabetes, nerve damage and high blood pressure. Hormonal issues, such as low testosterone, can also affect your level of sexual desire, which may stop you from getting an erection even with Viagra.

If you have an underlying medical condition that you think could affect your erections, it’s best to bring it up with your healthcare provider.

Low testosterone -- a common cause of a weak sex drive -- is easy to diagnose by getting your testosterone levels checked. If you have low testosterone levels, your healthcare provider may prescribe testosterone therapy to help you maintain your sex drive and wellbeing. 

If appropriate, your healthcare provider may prescribe medication to control your symptoms and improve your health, either on its own or in combination with medication for ED.

Porn is Affecting Your Sexual Performance

Believe it or not, watching too much porn could have a negative effect on your ability to get and maintain an erection.

Studies show that erectile dysfunction is increasingly affecting younger men, with a report from the Cleveland Clinic noting that approximately 40 percent of men are affected by some form of erectile dysfunction by the age of 40.

Although a direct link hasn’t yet been established, some experts believe that porn consumption may play a part in the increasing number of younger men developing ED.

Referred to as porn-induced erectile dysfunction, ED from porn may develop if you watch porn on a compulsive basis. 

If you watch porn often, or if you notice that your sexual tastes and expectations are starting to change as a result of the porn you use, you may benefit from taking a break from watching any porn for a few weeks.

Viagra Isn’t the Right Medication for You

Finally, Viagra might just not be a good match for your sexual needs and general health. There are several erectile dysfunction medications on the market, meaning Viagra isn’t the only option available.

These include tadalafil (the active ingredient in Cialis, a long-lasting ED medication), vardenafil (Levitra®) and avanafil (available as Stendra®, a newer medication for ED that has a lower risk of causing some side effects). 

Many of these medications offer their own unique advantages, such as Cialis’s ability to provide relief from erectile dysfunction for up to 36 hours per dose. 

In some cases, these advantages might make one of these medications a better choice for you than Viagra. 

Everyone is different, meaning that there’s no “best” ED medication for every person’s needs. If you think Viagra just isn’t right for you, consider talking to your healthcare provider about trying a different type of medication for ED.

Viagra and Psychological Erectile Dysfunction

Most cases of erectile dysfunction are caused by physical health issues, such as reduced blood flow or damage to the nerves in and around your penis.

However, some cases of erectile dysfunction can develop as a result of mental issues, such as depression, low self-esteem or sexual performance anxiety -- a form of anxiety that can lead to feelings of nervousness during sex.

Because Viagra works by increasing blood flow, it may not be effective if your ED is caused by depression, anxiety or a lack of interest in sex. 

Instead, you may benefit from taking part in counseling or seeing a psychiatrist to successfully treat your mental health issues.

We offer online psychiatry for conditions such as depression, anxiety disorders and others, as well as private online counseling that you can take part in from home. 

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What if Viagra Stops Working After Successful Use?

If you’ve used Viagra for several weeks, months or years, you may start to notice that it doesn’t work as well as it previously did.

Because Viagra works by increasing blood flow, it may become less effective if you experience a change in your health. For example, if you have a medical condition that affects blood flow to your penis and it becomes more severe over time, Viagra may become less effective.

Alternatively, if you develop a mental health condition that affects your level of interest in sex or your ability to feel comfortable in bed with your partner, it may affect your ability to get and stay hard even if Viagra previously worked well for you.

In these situations, it’s important to talk to your healthcare provider. They may suggest adjusting your dosage of Viagra, switching to a different ED medication, or taking other steps to treat your underlying health issues. 

When your ED is severe, or caused by something other than limited blood flow, your healthcare may recommend an alternative form of treatment.

Other options for treating ED include shockwave therapy, vacuum erection devices and surgical procedures such as the fitting of an inflatable penile implant.

These options are generally only used for very severe erectile dysfunction, or ED that’s caused by damage to the tissue of the penis from a surgical procedure or injury.

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Can Viagra Cause Side Effects?

Viagra and generic sildenafil can produce side effects. Most potential side effects of Viagra are mild and transient, although some may be persistent and bothersome.

Common side effects of Viagra include:

  • Headache

  • Flushing

  • Dyspepsia (indigestion)

  • Abnormal vision

  • Nasal congestion

  • Back pain

  • Myalgia (muscle pain)

  • Dizziness

  • Skin rash

In rare cases, Viagra may cause loss of vision, prolonged erections and other side effects. It’s important to inform your healthcare provider if you notice any persistent or severe issues while using Viagra or other medication to treat ED.

Viagra can interact with other medications, including nitrate medications and recreational drugs such as amyl nitrate “poppers.” When used together, these medications may trigger a sudden decrease in blood pressure that can cause dizziness, fainting or potentially severe issues.

To reduce your risk of experiencing side effects of drug interactions, it’s important to inform your healthcare provider about all medications you currently take or have recently taken before using Viagra or generic sildenafil.

Our full guide to Viagra side effects provides more information about potential adverse effects of Viagra, as well as the steps that you can take to reduce your risk of developing issues while you use Viagra to treat ED.

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Learn More About Treating Erectile Dysfunction

Viagra is a safe and effective medication for most men. However, as we’ve covered above, it’s far from uncommon to have days in which Viagra or other medications for erectile dysfunction just don’t seem to work as well as they should. 

If you have an “off day” while using Viagra, try letting a day or two pass before using it as you normally would before sex. If you experience the same issue, talk to your healthcare provider and let them know that you’re experiencing issues.

They may recommend making changes to the way you use Viagra or trying a different type of medication for ED. 

Interested in learning more about treating erectile dysfunction and improving your performance in bed?

We offer a range of evidence-based treatments for ED online, including Viagra, Cialis and their generic equivalents.

You can also learn more about treating ED in our detailed guide to the most effective treatment options for erectile dysfunction.

7 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

  1. Smith, B.P. & Babos, M. (2022, May 3). Sildenafil. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK558978/
  2. Dhaliwal, A. & Gupta, M. (2022, May 20). PDE5 Inhibitors. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK549843/
  3. Erection Ejaculation: How It Occurs. (2020, November 27). Retrieved from https://my.clevelandclinic.org/health/articles/10036-erection-ejaculation-how-it-occurs
  4. VIAGRA- sildenafil citrate tablet, film coated. (2017, August). Retrieved from https://www.accessdata.fda.gov/spl/data/40578e70-350a-4940-9630-55d90989c146/40578e70-350a-4940-9630-55d90989c146.xml
  5. Mulhall, J.O., Creanga, D.L. & Stecher, V.J. (2013). Improvement in erection hardness and intercourse success with first dose of sildenafil citrate 100 mg. International Journal of General Medicine. 6, 849-854. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3836683/
  6. Symptoms & Causes of Erectile Dysfunction. (2017, June). Retrieved from https://www.niddk.nih.gov/health-information/urologic-diseases/erectile-dysfunction/symptoms-causes
  7. Lakin, M. & Wood, H. (2018, June). Erectile Dysfunction. Retrieved from https://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/endocrinology/erectile-dysfunction/

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.