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Revatio vs. Viagra: What's the Difference?

Kristin Hall, FNP

Medically reviewed by Kristin Hall, FNP

Written by Our Editorial Team

Last updated 9/2/2020

Erectile dysfunction (ED) is one of the most common forms of male sexual dysfunction, with an estimated 30 million men affected in the United States alone.

If you’ve ever looked into the treatment options for erectile dysfunction, you’ve almost certainly heard of Viagra®, a medication for treating ED that contains the active ingredient sildenafil. 

The world of pharmaceuticals is full of similar substances marketed under very different brand names. Two that frequently cause confusion are Viagra and Revatio®, which also contains the active ingredient sildenafil citrate.

Viagra and Revatio are both manufactured and sold by the same company: Pfizer. Both work in the same way -- by increasing blood flow to specific areas of your body -- and both produce the same effects when they’re used as prescribed.

The main differences between these two medications are the dosage in which they’re made and the purpose for which each drug is marketed. 

Viagra is a medication for treating erectile dysfunction, while Revatio is a medication that’s used to treat pulmonary arterial hypertension (PAH).

Below, we’ve listed how Viagra and Revatio differ, both from a marketing perspective and from a functional perspective.

We’ve also provided more information on which drug is the most effective option for treating ED and improving your sexual experience.

TLDR: Revatio vs. Viagra

Viagra and Revatio both contain the same active ingredient, sildenafil. They’re both sold by the same company, Pfizer. At a brief glance, they might look more or less identical. But there are a few key differences between these medications that are worth keeping in mind. 

Before we get into those, let’s go over the basics of how Viagra and Revatio both work. Both of these medications belong to a class of drugs called PDE5 inhibitors, or phosphodiesterase type 5 inhibitors.

PDE5 inhibitors work, as their name suggests, by inhibiting the effects of the phosphodiesterase type 5 enzyme. 

So, what does this mean? PDE5 is an enzyme that’s present in the smooth muscle cells of your blood vessels. Its specific function within your body is complex, but at a basic level, PDE5 helps to control the level of blood flow through blood vessels in certain parts of your body.

It does this by causing your blood vessels to constrict (meaning become narrower). When PDE5 is inhibited by the sildenafil found in Viagra or Revatio, your blood vessels become larger, letting more blood flow to certain types of tissue.

This helps you to get and maintain an erection (in the case of Viagra) or increase the amount of blood that can flow to your lungs (in the case of Revatio).

We’ve covered this process in more detail below. However, for now, here are a few of the major differences between Viagra and Revatio that you should be aware of:

  • Although both medications contain sildenafil, they’re dosed for different purposes. Since erectile dysfunction can vary in severity, Viagra comes in several doses, ranging from 25 to 100mg per tablet. Revatio, on the other hand, is only available as a 20mg oral tablet. 

  • Viagra is generally prescribed solely to treat erectile dysfunction, whereas Revatio tends to be prescribed to treat pulmonary hypertension. 

  • Despite only being approved as a treatment option for erectile dysfunction, sildenafil can also be used off-label to treat premature ejaculation, either by itself or with other drugs. 

  • Both medications can cause similar side effects, including headaches, nasal congestion, runny nose, flushing, indigestion and, in rare cases, blurred vision and temporary loss of hearing.

  • Both medications can cause drug interactions, including dangerous interactions if used with blood pressure medications such as nitrate medications and alpha-blockers.

  • You’ll need a prescription to buy either medication. As part of getting a prescription, it’s important to inform your healthcare provider about any medical conditions you have or have previously experienced. 

What is Viagra?

Viagra is a brand-name drug for erectile dysfunction that’s produced by Pfizer. It comes in tablet form in several doses and is designed for use as needed approximately 60 minutes before your planned time of sexual activity.

Each tablet of Viagra contains either 25mg, 50mg or 100mg of sildenafil. Most men with ED who use Viagra start with a dosage of 50mg, which may be adjusted to 25 or 200mg over time based on their response to the medication.

Viagra is generally effective when it’s used from 30 minutes to four hours before sex. After four hours, the medication becomes less effective and may not provide a significant amount of relief from erectile dysfunction.

Pfizer developed sildenafil, the active ingredient in Viagra, in the late 1980s and early 1990s. It was originally developed as a treatment for angina, a form of chest pain that’s caused by limited blood flow to the heart muscles.

During early tests, the researchers discovered that many volunteers reported developing penile erections while using sildenafil -- at the time referred to as “UK-92,480” -- as a form of treatment for angina.

The researchers concluded that sildenafil could be more effective as a form of treatment for ED than angina, and switched the focus of their studies to developing a medication to treat erectile dysfunction in men.

Sildenafil went through clinical trials in the early 1990s and in 1996 received a patent. It gained approval from the FDA in 1998, with Pfizer using the brand name Viagra to promote sildenafil in the United States and around the world. 

Viagra is marketed specifically as a treatment for erectile dysfunction. While it does offer some benefits for hypertension (high blood pressure) and angina, these aren’t the medication’s main purposes and Pfizer does not market Viagra as a treatment for either of these conditions. 

Viagra is a prescription medication, meaning you’ll need to talk to a healthcare provider before you can use it to treat erectile dysfunction. 

Because Viagra has been on the market for several decades, it’s now sold in its original brand name form and as a generic medication as sildenafil.

Sildenafil, or generic Viagra, contains the same active ingredient as brand-name and offers the same benefits as the brand-name Viagra sold by Pfizer. 

How Does Viagra Work?

Viagra works by inhibiting the effects of PDE5, an enzyme that controls blood flow to the erectile tissue inside your penis.

Getting and maintaining an erection depends on two main things: sexual stimulation and healthy blood flow.

When you feel sexually stimulated, your nervous system signals to the muscle tissue inside your penis, causing it to relax. Your blood vessels become larger, allowing blood to flow into a type of erectile tissue inside your penis called the corpora cavernosa. 

This increase in blood flow causes the corpora cavernosa to expand in size and become firmer, creating an erection. A fibrous membrane called the tunica albuginea wraps around this tissue, helping you to maintain your erection during sexual intercourse.

By inhibiting the effects of PDE5, Viagra makes it easier for blood to flow into your penis, letting you get and maintain an erection.

Contrary to popular belief, Viagra doesn’t have any impact on your sex drive, and it won’t cause you to get an erection if you don’t feel sexually aroused. Instead, it works solely by allowing for blood to flow into your penis when you’re in the mood for sex. 

Our guide to how Viagra works goes into more detail about the biological process of getting an erection, as well as how Viagra can make it easier if you’re prone to ED.

Side Effects of Viagra

Like all prescription medications, Viagra has the potential to cause a range of side effects. Most of these are minor, although some may be persistent and/or bothersome.

Common side effects of Viagra and generic sildenafil include:

  • Headache

  • Flushing

  • Dyspepsia (indigestion/heartburn)

  • Nausea (upset stomach)

  • Nasal congestion

  • Abnormal vision

  • Back pain

  • Myalgia (muscle pain)

  • Dizziness

  • Skin rash

Many of these side effects are more common when Viagra is taken at a moderate or high dose, such as 50 or 100mg.

In rare cases, Viagra and generic sildenafil may cause other side effects, including prolonged or painful erections (referred to as priapism). Priapism is an extremely rare side effect that requires medical attention.

Our guide to Viagra’s side effects explains these potential risks in more detail, with detailed data on how frequently side effects occur and what you can do to deal with them. 

What is Revatio?

Revatio is a second brand name for sildenafil. Unlike Viagra, which is marketed as a treatment for erectile dysfunction, Revatio is marketed as a treatment for pulmonary arterial hypertension, a form of high blood pressure that affects the arteries of the lungs. 

Both Revatio and Viagra are brand names owned by Pfizer, the pharmaceutical corporation that originally designed, tested and marketed sildenafil.

While Viagra entered the market in the late 1990s, Revatio was approved by the FDA in June of 2005 as a treatment for PAH.

Revatio contains a lower dose of sildenafil than Viagra. Each Revatio tablet contains 20mg of sildenafil. In comparison, each Viagra tablet contains either a 25mg, 50mg or 100mg dose of sildenafil.  

This means that Revatio contains approximately one fifth of the amount in the strongest Viagra tablet. Despite the different strengths of these medications, the sildenafil in Viagra and Revatio is exactly the same.

Aside from brand name and dosage, Viagra and Revatio are essentially the same drug with the exact same effects and side effects on the body.

This means that although Revatio is marketed as a treatment for pulmonary hypertension, it can provide relief from erectile dysfunction. 

While the amount of sildenafil per tablet is lower than Viagra, many men with mild or moderately severe ED find that it’s effectively treated by the 20mg of sildenafil found in Revatio.


How Does Revatio Work?

Because it contains the same active ingredient as Viagra, Revatio works in the same way within your body. 

PDE5, the enzyme that sildenafil targets, isn’t solely found in the blood vessels that supply your penis. It’s also found throughout your vascular system, including in the blood vessels located in your lungs, which are referred to as the pulmonary vasculature.

By inhibiting the effects of PDE5, the sildenafil in Revatio can relax the smooth muscle cells in your pulmonary vascular system, expand your blood vessels and allow for stronger blood flow between your heart and lungs.

This can help to relieve pulmonary hypertension and prevent damage that may occur in certain parts of your heart over time. 

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Revatio or Viagra: Which is Best?

Because Viagra and Revatio both contain sildenafil, the two medications have the same effects on your body.

From a purely functional standpoint, both medications can be used to treat erectile dysfunction, as they both contain the same active ingredient. In fact, some generic sildenafil tablets contain the same 20mg dosage as one Revatio tablet. 

If you have severe erectile dysfunction, the higher dosage offered by 50mg and 100mg tablets of Viagra might be more effective at treating your symptoms than the slightly lower 20mg dose of sildenafil that’s provided by Revatio.

It’s worth noting that the higher dosage of sildenafil used in the 50mg and 100mg Viagra tablets could result in more obvious, severe side effects compared to the mild dose of sildenafil used in Revatio.

As always, the best option is to consult your healthcare provider. When they’re prescribing you sildenafil to treat erectile dysfunction, they’ll provide a specific dose and suggest the medication that’s best suited to your symptoms and needs. 

From a cost perspective, the best option is generally to choose generic sildenafil, the ingredient that’s used in both Viagra and Revatio. 

Sildenafil has been available as a generic medication for several years. Buying generic lets you access the same benefits for ED as brand-name medications such as Viagra or Revatio, all at a significantly lower price per tablet.

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What to Know Before Using Viagra or Revatio

Regardless of whether you choose brand-name Viagra, Revatio or generic sildenafil, there are a few things that you should be aware of before using this type of medication to treat ED.

The first is that any medication that features sildenafil (or other PDE5 inhibitors, such as tadalafil (the active ingredient in Cialis®), vardenafil (Levitra®) or avanafil (Stendra®) has the potential to interact with other medications, including drugs for high blood pressure and heart disease.

Because of this, it’s critical that you inform your healthcare provider if you currently use or have recently used any nitrates, alpha-blockers or similar medications. It’s also essential to avoid any amyl nitrate, amyl nitrite or butyl nitrate “poppers” while using any type of medication for ED.

The second is that it’s also important to inform your healthcare provider if you have any medical conditions before using either medication.

Make sure to inform your healthcare provider if you have any physical condition, including heart disease, sickle cell anemia, multiple myeloma, or leukemia, a deformed penis shape, a bleeding problem, loss of vision, retinitis pigmentosa, liver or kidney problems, or stomach ulcers.

It’s also important to inform your healthcare provider if you have ever had a heart attack, stroke, chest pain, or other cardiovascular event, or if you develop shortness of breath while taking any type of medication.

If you develop any side effects while using Viagra, Revatio or generic sildenafil, make sure to let your healthcare provider know as soon as you can. 

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The Bottom Line on Revatio and Viagra

Viagra and Revatio are two brand names used to market the same medication: sildenafil. Both medications work in the same way within your body, although one is marketed as a medication for treating ED and the other is marketed as a treatment for pulmonary arterial hypertension. 

Because Revatio and Viagra both contain sildenafil, both prescription drugs will increase blood flow to your penis and reduce the severity of erectile dysfunction. 

However, the low dose of sildenafil used in Revatio may make it less suitable if you’re affected by moderate or severe ED.

If you’re worried by erectile dysfunction, you’re not alone. Our detailed guide to the causes of erectile dysfunction and your options for treating it discusses how ED can develop, as well as the steps that you can take to improve your erections and sexual function.

You can also access a wide range of treatments for ED, including Viagra and sildenafil, using our selection of erectile dysfunction medications, which are available following a consultation with a licensed healthcare provider. 

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. Symptoms & Causes of Erectile Dysfunction. (2017, July). Retrieved from https://www.niddk.nih.gov/health-information/urologic-diseases/erectile-dysfunction/symptoms-causes
  2. 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
  3. REVATIO- sildenafil citrate tablet, film coated. (2020, February). Retrieved from https://www.accessdata.fda.gov/spl/data/eeeb2d77-bc88-45e8-afb2-f18cc8aa941e/eeeb2d77-bc88-45e8-afb2-f18cc8aa941e.xml
  4. Dhaliwal, A. & Gupta, M. (2022, May 20). PDE5 Inhibitors. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK549843/
  5. 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. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7097805/
  6. Erection Ejaculation: How It Occurs. (2020, November 27). Retrieved from https://my.clevelandclinic.org/health/articles/10036-erection-ejaculation-how-it-occurs
  7. Revatio (Sildenafil Citrate). (2005, December). Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/nda/2005/021845s000_RevatioTOC.cfm

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.