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Viagra (Sildenafil): Uses, Benefits and Side Effects

Katelyn Brenner FNP

Reviewed by Katelyn Hagerty, FNP

Written by Geoffrey Whittaker

Published 04/08/2021

Updated 07/10/2023

Viagra: the little blue pill and man’s (other) best friend. Whether you’re a senior in high school or a senior-living resident, you’ve definitely heard of this medication for erectile dysfunction (ED) — but our guess is you haven’t heard it all. 

Most men and women know what Viagra does, but not everyone knows how it does it. Questions about what Viagra actually is, how safe it is, who should use it and when are regularly at the top of Google search results.

Viagra is a medication for erectile dysfunction that can help adult men of all ages who aren’t seeing the firm, reliable erectile function that radiates confidence in the bedroom — and as long as you’re using it as directed, it’s considered safe and effective. 

But those fast facts hardly paint the complete picture of what this boner-benefitting pill can do.

Below, we’ll explain the origin story of Viagra, the benefits of Viagra for men and the potential side effects of taking it.

Before we dive into the history, medical jargon and warnings, let’s take a look at the erectile info you probably came here for in the first place.

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Brand-name Viagra (and the generic version known as sildenafil) is an effective medication for the treatment of erectile dysfunction. But to understand how Viagra works, we need to look at ED briefly.

When your small soldier gets some sexual stimulation, erections happen. The smooth muscles of the penis relax, causing penile arteries to widen for increased blood flow to the penis.

When this happens, the blood becomes trapped inside, producing a firm erection the way a clown produces a balloon.

When this process is interrupted, it can lead to erectile dysfunction, which may appear as partial erections, short-lived erections or no erections at all.

The reason these muscles malfunction is because of an enzyme called phosphodiesterase type 5 (PDE-5). Viagra inhibits PDE-5 and acts as a vasodilator (something that dilates blood vessels). As a result, muscles work the way they’re supposed to, and your erection functions as normal.

In most cases, a single tablet is all that’s required to produce firmer and longer-lasting erections. Studies have shown a 70 to 80 percent success rate in patients who use this treatment.

For more on how to take Viagra, check out our blog.

Viagra (otherwise known by the generic name sildenafil citrate) needs no introduction — but we’ll give one anyway.

Since 1998, this Pfizer-created drug has come out on top for the management of erectile dysfunction. But sildenafil citrate began its clinical journey as a medication intended to treat hypertension (high blood pressure) and angina (chest pains due to high blood pressure).

While sildenafil can still be used to treat hypertension, the primary benefit of this PDE-5 inhibitor is erectile dysfunction. Also, other first-line treatment options for blood pressure and heart disease are now considered before Viagra.

That’s not to say it doesn’t still offer (or get prescribed for) other uses — there are a few other things Viagra might also help with.

Are there other uses for Viagra? Potentially.

Viagra’s ability to increase blood flow has led to its decades-old bragging rights as a treatment for erectile dysfunction. This feature, however, makes the medication useful for managing other conditions — plenty of claims have been made about the health benefits of Viagra for men.

Some sources claim Viagra might make you last longer in bed, while others say it’s good for heart health. But while this medication can help with the management of erectile dysfunction, it isn’t a one-stop shop for every sexual improvement you’d like to achieve.

With that in mind, you should know that Viagra will not increase penis size, it may not boost your sex drive, and it hasn’t really been shown to prevent tiredness during sex. We’re not just saying that, either — a study carried out on 60 men confirmed this.

Not all claims about Viagra have been supported by enough science to convince us — let alone the FDA — of their validity.

Still, a few potential health benefits stick out. Viagra might help with:

  • Pulmonary arterial hypertension (PAH)

  • Mountain sickness

  • Raynaud’s phenomenon

  • Heart disease

Below, we’ll explain how sildenafil might affect people with these conditions in more detail.

Pulmonary Arterial Hypertension (PAH)

Surprisingly, your penis and your lungs might have something in common (beyond the fact that you probably want both to keep working as long as possible).

Pulmonary arterial hypertension (PAH) is a pretty serious condition that occurs when the tiny vessels in your lungs narrow, resulting in high blood pressure in the lungs.

Normally, the pulmonary artery supplies oxygen-filled blood from the lungs to the heart. But with this condition, the arteries are blocked, narrowed or even destroyed, preventing healthy blood flow.

When this happens, blood pressure in the lungs increases, and the heart has to work harder to get blood through those tiny arteries — a process that can eventually tire out the lungs, potentially causing heart failure.

Viagra can help reduce blood pressure in the lungs within its role as a vasodilator — essentially, it can do for your lungs what it does for your penis.

Since PDE-5 — the same enzyme that prevents blood flow to the penile smooth muscles — is also spread throughout the lungs, Viagra can bind to this enzyme, causing the arteries in the lungs to relax and widen. This reduces blood pressure to the lungs and helps ease the effort of the heart in pumping blood away from the lungs.

In a study comparing the effects of sildenafil (generic Viagra) and bosentan (a popular drug for managing PAH), sildenafil was found to be just as effective in managing the condition when combined with other therapies, like diuretics.

Sildenafil for managing PAH is marketed under the name Revatio with a particular dosage. It’s one of several FDA-approved treatment methods for the condition.

Mountain Sickness

Beyond a massive adrenaline rush, mountain climbing can come with a bout of altitude sickness, sometimes called mountain sickness.

At great heights, mountain sickness can cause dizziness, headaches, muscle aches and (in severe cases) high altitude pulmonary edema (HAPE). This is when blood vessels in the lungs leak, filling them with fluid.

These symptoms occur because your blood-oxygen levels are reduced by the altitude when you’re high up on the mountain. It can be fatal if the person experiencing it remains at a high altitude (which is why you hear all those Mount Everest horror stories). 

Some reports say that since Viagra is able to widen blood vessels, it can increase blood flow through the heart, permitting more oxygen to the lungs and improving oxygen supply to the rest of the body. 

Basically, the argument is that Viagra can help to prevent mountain sickness. However, there’s very little research to support this.

One study tried to determine the effectiveness of sildenafil in ten cyclists riding at a high altitude. The medication was found to improve heart function and oxygen levels in the blood. It also enhanced performance levels in some participants.

That said, ten cyclists are hardly enough to convince us (let alone the U.S. Food and Drug Administration) to approve something as a treatment. On the bright side, if you plan to have sex in Utah, you now have a fun fact to share with your date.

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Raynaud’s Phenomenon

Even when you least expect it, your body is mostly always looking out for you. For instance, it preserves body heat in cold temperatures by restricting blood flow to the skin.

Something similar occurs in Raynaud’s phenomenon (sometimes called a Raynaud’s attack). Blood flow to the hands and feet is reduced, causing them to feel numb and cool. Episodes may also occur when you’re under emotional stress.

Raynaud’s phenomenon is more annoying than it is serious, although severe cases can lead to tissue death in the hands or feet, which could require amputation.

Viagra’s ability to decrease the number of attacks in people affected by Raynaud’s phenomenon was confirmed in a small study. Participants started off on 100 milligrams of sildenafil for three days before moving on to 200 milligrams for two days. The medication was able to treat the condition and was well tolerated.

Viagra is definitely not an appropriate first-line treatment for Raynaud’s, but in situations where more common medications have failed, it could be an option.

Heart Disease

Viagra has come full circle in managing heart disease. As it turns out, this medication can help with heart failure.

One of the most common forms of heart failure occurs when the left heart ventricle (responsible for pumping oxygen-rich blood to the rest of the body) is unable to effectively do its job. This causes blood to back up into the lungs, which can lead to a buildup of fluid.

In at least one study, regular long-term use of sildenafil has been shown to improve left ventricle function while strengthening the structure of a failing left ventricle.

Sildenafil’s role as a PDE-5 inhibitor might help prevent the thickening of heart muscles, a feature that makes it difficult to pump blood. Viagra has also shown real promise for increasing the amount of blood pumped by the heart, but more research is necessary.

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Like any medication, there are side effects of Viagra that come along with its many benefits. Generally, Viagra is safe when used as directed, though some users may experience mild to moderate side effects. 

Viagra may cause common side effects, including:

  • Flushing

  • Headaches

  • Back pain and other body aches

  • Indigestion

These are usually mild and will often go away over time. Not sure if something is a side effect of Viagra? Check out our Viagra (sildenafil) side effects blog for a more comprehensive list.

What you really need to watch out for are the more serious side effects, which may include:

  • Eye problems like blurred vision, retinitis pigmentosa or vision loss

  • Chest pain

  • Hearing loss

  • Priapism (prolonged erections)

  • Increased risk of heart attack

  • Other heart problems

If you have an irregular heartbeat, hearing loss, vision loss, an allergic reaction, Peyronie’s disease, sickle cell anemia or are being treated for leukemia or other medical conditions, share this with your healthcare provider.

A word on sildenafil drug interactions: Mixing antihypertensive prescription drugs with Viagra may cause low blood pressure. Since the medication has blood pressure-lowering abilities, pairing it with another medication geared toward reducing blood pressure could cause a dangerous or potentially fatal drop in blood pressure. 

Likewise, Viagra should not be combined with antiretroviral drugs used to treat HIV/AIDS, as it can cause an increased concentration of sildenafil in the body. We probably don’t need to explain this, but women who are breastfeeding shouldn’t take this medication, either.

Because of the risks of this medication, people taking alpha-blockers, antifungals (like itraconazole or ketoconazole), antibiotics (like erythromycin), over-the-counter nitrate and nitrate supplements (like amyl nitrate or nitroglycerin) or recreational drugs (like poppers) should tell a healthcare professional before they take Viagra. 

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Viagra has made its way to medicine cabinets the world over as a trusted medication for erectile dysfunction, as well as some other conditions. Still, you can’t treat this stuff like an over-the-counter painkiller. 

We know sexual activity is supposed to be somewhat off the cuff, but you shouldn’t take the medication with abandon. Using Viagra only as directed by a healthcare provider is essential for avoiding many dangerous side effects that can occur when you go off-script with your prescription.

Interested in trying Viagra? Here are the most important things to know:

  • Viagra is a proven treatment for erectile dysfunction, and while it may not do anything to your sexual experience in terms of libido, it can have incredible effects if you’re having problems maintaining erections.

  • Other medications for ED, like Cialis (tadalafil), Levitra (vardenafil) and Stendra (avanafil), may also help. For more erectile dysfunction treatments, check out our blog.

  • Always consult a trusted medical professional for medical advice on the best ways to use this medication — and make sure you share other health conditions with the professional you speak to about ED medication.

  • If you’re in the market for a remedy, we can help you get a prescription for medication, including products like our chewable ED meds hard mints. 

There are a bunch of informative articles on our blog if you want to learn more about Viagra and sexual health. We can also help you get easy access to affordable Viagra from the comfort of your home.

Explore your options from Hims today.

12 Sources

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  2. Guazzi, M., Vicenzi, M., Arena, R., & Guazzi, M. D. (2011). PDE5 inhibition with sildenafil improves left ventricular diastolic function, cardiac geometry, and clinical status in patients with stable systolic heart failure: results of a 1-year, prospective, randomized, placebo-controlled study. Circulation. Heart failure, 4(1), 8–17. https://www.ahajournals.org/doi/10.1161/CIRCHEARTFAILURE.110.944694?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed.
  3. Herrick, A.L., van den Hoogen, F., Gabrielli, A., Tamimi, N., Reid, C., O’Connell, D., Vázquez-Abad, M.-D. and Denton, C.P. (2011), Modified-release sildenafil reduces Raynaud’s phenomenon attack frequency in limited cutaneous systemic sclerosis. Arthritis & Rheumatism, 63: 775-782. https://onlinelibrary.wiley.com/doi/epdf/10.1002/art.30195.
  4. Hsu, A. R., Barnholt, K. E., Grundmann, N. K., Lin, J. H., McCallum, S. W., & Friedlander, A. L. (2006). Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia. Journal of Applied Physiology. https://journals.physiology.org/doi/full/10.1152/japplphysiol.00806.2005?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org.
  5. Murdoch D. (2010). Altitude sickness. BMJ clinical evidence, 2010, 1209. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2907615/
  6. Wilkins, M. R., Paul, G. A., Strange, J. W., Tunariu, N., Gin-Sing, W., Banya, W. A., Westwood, M. A., Stefanidis, A., Ng, L. L., Pennell, D. J., Mohiaddin, R. H., Nihoyannopoulos, P., & Gibbs, J. S. (2005). Sildenafil versus Endothelin Receptor Antagonist for Pulmonary Hypertension (SERAPH) study. American journal of respiratory and critical care medicine, 171(11), 1292–1297. https://www.atsjournals.org/doi/10.1164/rccm.200410-1411OC.
  7. Oldroyd SH, Manek G, Sankari A, et al. Pulmonary Hypertension. [Updated 2022 Dec 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482463/.
  8. McCullough A. R. (2002). Four-year review of sildenafil citrate. Reviews in urology, 4 Suppl 3(Suppl 3), S26–S38. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1476025/.
  9. Ghofrani, H. A., Osterloh, I. H., & Grimminger, F. (2006). Sildenafil: from angina to erectile dysfunction to pulmonary hypertension and beyond. Nature reviews. Drug discovery, 5(8), 689–702. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7097805/.
  10. Mondaini, N., Ponchietti, R., Muir, G. H., Montorsi, F., Di Loro, F., Lombardi, G., & Rizzo, M. (2003). Sildenafil does not improve sexual function in men without erectile dysfunction but does reduce the postorgasmic refractory time. International Journal of Impotence Research, 15(3), 225-228. https://www.nature.com/articles/3901005.
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