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Sildenafil vs. Viagra: differences, dosages, costs

11 min read

Written by: 

Sonia Rebecca Menezes

Reviewed by: 

Raagini Yedidi, MD

Published: Aug 25, 2022

Updated:  Jan 09, 2025

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Key takeaways

  • When comparing Viagra vs. sildenafil, the two medications are functionally identical in how they work to treat erectile dysfunction, as both contain the active ingredient sildenafil citrate.

  • Brand-name Viagra is significantly more expensive. For those prioritizing affordability, sildenafil is a practical choice without sacrificing effectiveness.

  • Ro offers brand-name Viagra, generic sildenafil, and Ro Sparks—a fast-acting 2-in-1 treatment combining sildenafil and tadalafil.

  • The choice between Viagra, sildenafil, and other ED medications depends on your budget, lifestyle, and personal preferences.

Here's what we'll cover

Have better sex

Here's what we'll cover

Key takeaways

  • When comparing Viagra vs. sildenafil, the two medications are functionally identical in how they work to treat erectile dysfunction, as both contain the active ingredient sildenafil citrate.

  • Brand-name Viagra is significantly more expensive. For those prioritizing affordability, sildenafil is a practical choice without sacrificing effectiveness.

  • Ro offers brand-name Viagra, generic sildenafil, and Ro Sparks—a fast-acting 2-in-1 treatment combining sildenafil and tadalafil.

  • The choice between Viagra, sildenafil, and other ED medications depends on your budget, lifestyle, and personal preferences.

Viagra might be the most well-known prescription medication available to treat erectile dysfunction (ED), but that doesn’t mean it’s the only option. Sildenafil is the active ingredient in Viagra (the full name of the drug is sildenafil citrate). It’s also sold without the brand name, sometimes called "generic Viagra" or simply "sildenafil." 

Think of Viagra as the brand-name version of sildenafil. It’s like how Kleenex is synonymous with tissues—they’re household names, but at their core, they’re just brands.

Generic sildenafil is essentially the same product, just without the branded packaging or higher price point.

Here's what you need to know about these drugs.

Viagra Important Safety Information: Read more about serious warnings and safety info.

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Sildenafil vs. Viagra: what’s the difference?

A common question people ask is, “Is sildenafil the same as Viagra?” The answer is essentially yes—Viagra is simply the brand-name version, while sildenafil is the generic alternative.

They both treat ED and share the same active ingredient, sildenafil citrate. Both medications belong to a group of drugs called PDE5 inhibitors, which relax the muscles in blood vessel walls to improve blood flow to the penis. For all intents and purposes, generic sildenafil is just as good as Viagra - They are both equally effective because they have the same active ingredient and work the same way in the body. With that said, let’s go over some of the key differences that could influence your choice.

Cost

One of the most noticeable differences between Viagra and sildenafil is the cost. Viagra, manufactured and marketed by Pfizer, is typically more expensive, largely due to its brand recognition.

Generic sildenafil, on the other hand, is produced by multiple manufacturers, which generally makes it more affordable while containing the same active ingredient.

For context, a single dose of brand-name Viagra can cost up to $70, whereas generic sildenafil is often available for as little as under a dollar. This significant price difference often influences the decision between the two options.

Dosage options

Viagra is available in specific dosages, usually 25 mg, 50 mg, or 100 mg tablets.

Sildenafil, as a generic option, may come in the same range but also offers more dosage flexibility since it’s manufactured by different companies. It is also approved for other indications and can come in a 20 mg dose as well. For example, Ro Sparks is a combination drug that contains 55 mg of sildenafil.

That said, these examples are for informational purposes only and not a substitute for medical advice. ED medications should always be prescribed by a healthcare provider who can advise you on the right dosage based on your individual health and needs.

Appearance

Viagra is famously marketed as the “little blue pill.” Its shape and color are instantly recognizable. Generic sildenafil, however, comes in a variety of forms—different shapes, sizes, and colors—depending on the manufacturer.

While these cosmetic differences don’t affect how the drug works, they could matter if you value familiarity.

Manufacturer

Viagra is exclusively manufactured by Pfizer, the company that originally developed the medication. This guarantees consistent quality, branding, and formulation across every pill.

In contrast, generic sildenafil is produced by various manufacturers. While the active ingredient—sildenafil citrate—remains the same in all versions, there can be slight differences in the inactive ingredients.

These are the non-medicinal components like fillers, binders, or coloring agents used to shape and stabilize the pill. For most people, these variations in inactive ingredients don’t affect how the medication works or its safety.

Is Viagra or sildenafil right for me?

If you’ve been googling all the types like sildenafil, sildenafil citrate, and Viagra and want to figure out which is best for you, it comes down to your priorities. The main differences are cost, brand loyalty, or a preference for specific formulations.

Choose Viagra if:

  • You trust the brand: If the reassurance of a well-known name matters to you, Viagra’s reputation as the original ED medication might win you over.

  • You prefer consistency: Viagra’s uniform manufacturing, regardless of where you buy the pill from, gives you some sense of what to expect.

  • You don’t mind the cost: If price isn’t a major concern, sticking with the branded option could be the simplest choice.

Choose sildenafil if:

  • You’re cost-conscious: Generic sildenafil is significantly more affordable, making it accessible to more people without compromising on effectiveness.

  • You’re open to variety: If you don’t mind a pill that looks different or comes from a different manufacturer, sildenafil gives you more options.

  • You want flexibility: With multiple manufacturers in play, you might find a broader range of dosage options, pricing flexibility, and more options for shipping.

What is Viagra?

Viagra, made by Pfizer, is one of the most well-known treatments for erectile dysfunction (ED). Its active ingredient, sildenafil citrate, works by improving blood flow to the penis, helping you achieve and maintain an erection when you are aroused. Viagra is available in three dosages: 25 mg, 50 mg, and 100 mg, giving you options based on your needs.

It’s usually taken about 30 to 60 minutes before sex, although it can start working in as little as 12 minutes. The effects of Viagra last around four to six hours, although factors like your age, overall health, and even what you’ve eaten can influence how well it works.

Interestingly, Viagra wasn’t initially designed to treat ED. Pfizer originally developed sildenafil to treat high blood pressure and chest pain. During clinical trials, researchers noticed an unexpected side effect: male participants reported improved erections. In 1998, the FDA approved the now-iconic "little blue pill" as the first treatment for ED.

Sildenafil became available as a generic medication in December of 2017. Until then, only two companies (Pfizer and Teva Pharmaceuticals) could produce the drug. This change allowed other companies to manufacture and sell "generic Viagra."

What is sildenafil (generic Viagra)?

"Generic Viagra" is typically called sildenafil, and it has the same active ingredient and is dosed the same as Viagra, but it is not sold under the brand name.

These generic drugs are bioequivalent, which means they act the same way and produce the same results in the body. A single dose of brand-name Viagra can cost as much as $70, while you can get the generic version for $3 a dose or even less.

Sildenafil is the active ingredient in Viagra and "generic Viagra," but those aren't the only medications that use it. Under the brand name Revatio, sildenafil is approved by the FDA to treat pulmonary arterial hypertension (PAH), a rare lung disorder.

Side effects of Viagra vs. sildenafil

Since Viagra and generic sildenafil share the same active ingredient, they also share the same potential side effects. While most people tolerate these medications well, it’s important to know what to expect and when to seek help.

Common side effects of Viagra and sildenafil

  • Headaches

  • Facial flushing

  • Indigestion

  • Muscle aches and back pain

  • Stuffy nose

  • Nausea

  • Vision changes (e.g., mild blurring, color changes, increased light sensitivity)

Most of these side effects resolve on their own as the medication leaves your body. 

Rare side effects of Viagra and sildenafil

In rare cases, Viagra and generic sildenafil may cause serious side effects, such as:

  • Priapism (an erection lasting longer than four hours which can sometimes be painful)

  • Sudden blurred vision

  • Loss of vision

  • Loss of hearing

  • Lightheadedness and dizziness (typically brought on by low blood pressure when combined with other medications)

  • Dizziness

If you experience any of these severe side effects, seek medical attention immediately.

Drug interactions

Viagra and generic sildenafil can interact with other medications, especially those used for high blood pressure and heart conditions. These drug interactions include: 

  • Nitrates: One of the most serious interactions with both sildenafil and Viagra is with nitrates, which are often prescribed for chest pain (angina) or other heart conditions. Combining nitrates with Viagra or sildenafil can cause a dangerous drop in blood pressure. Nitrates include medications like nitroglycerin and recreational “poppers.” That’s why it’s usually recommended not to take these medications together.

  • Alpha-blockers: These medications are used for high blood pressure and prostate conditions called Alpha-blockers. They also interact with sildenafil and Viagra by lowering blood pressure too much, so if you are taking an alpha blocker your provider may recommend against ED medication or prescribe it at a lower dose.

  • CYP3A4 interactions: Certain drugs that affect the CYP3A4 enzyme can interfere with how your body processes sildenafil and Viagra, potentially increasing the risk of side effects. These include antifungals like ketoconazole, some HIV medications, and antibiotics like erythromycin. It’s always important to update your healthcare provider regarding what medications you take so that you can be sure you are being as safe as possible.

Other health considerations: Both sildenafil and Viagra are generally safe, but if you have a history of heart conditions, such as high or low blood pressure or heart disease, you should let your healthcare provider know so they can take that into account when planning your treatment,

Sildenafil vs. Viagra dosage

While both medications are equally effective, you might be wondering: “Is sildenafil stronger than Viagra?” The strength of the medication depends on the dosage, not the brand or generic label.

Both Viagra and generic sildenafil are available in similar dosage options for treating ED: 25 mg, 50 mg, and 100 mg tablets. Most people start with the 50 mg dose, which is often effective for a majority of users.

Generic sildenafil is also commonly available in a 20 mg dose. This is primarily because sildenafil is also sold under the brand name Revatio for treating pulmonary arterial hypertension (PAH), a specific type of high blood pressure affecting the lungs. While Revatio is FDA-approved for PAH, healthcare providers can prescribe the 20 mg dose of sildenafil off-label to treat ED when appropriate.

Your healthcare provider will recommend the dosage of Viagra or sildenafil that’s best for your needs. For most people, the standard doses (25 mg–100 mg) work effectively to improve erectile function.

Since both Viagra and sildenafil contain the same active ingredient, you can expect identical results from equivalent doses of either medication.

  • Timing: Take Viagra or sildenafil about 30–60 minutes before sexual activity. Both medications work best within this timeframe but can be effective for up to four hours.

  • With or without food: You can take either medication on an empty stomach or with food, but avoid high-fat meals. Heavy meals can slow down how quickly the medication starts working.

If you don’t notice improvement in your ED symptoms after taking Viagra or sildenafil, don’t increase your dose on your own. Talk to your healthcare provider instead—they may adjust your dosage or suggest trying a different medication. They might even suggest adjusting the timing of when you take it.

Sildenafil vs. Viagra vs. Cialis: which is better?

When comparing Cialis, Viagra, and sildenafil, the best choice depends on your lifestyle, priorities, and budget. All three are effective treatments for ED and belong to the same class of medications, PDE5 inhibitors. Here’s how they stack up against each other.

Cialis offers flexibility with two dosing options: A daily low dose for men who prefer readiness at all times or an as-needed dose taken about 30 minutes before sex. Its effects last up to 36 hours, making it ideal for those who want spontaneity or will have sex frequently over the course of a day and a half––hence the nickname, the "Weekend Pill."

Viagra and generic sildenafil are best suited for occasional, planned sexual activity. They’re taken about 30–60 minutes before sex, and their effects last 4–6 hours. This makes them a great choice if you prefer a medication you only take when needed without keeping it in your system longer.

Ultimately, all three medications are effective at treating ED, but the best choice depends on your personal needs. You can speak with your healthcare provider to determine which option is right for you.

Cialis Important Safety Information: Read more about serious warnings and safety info.

Alternatives to sildenafil and Viagra

While sildenafil and Viagra are effective for many, other ED treatments might better suit your needs.

  • Vardenafil offers a slightly longer duration of action, lasting up to 6 hours. It can sometimes start working in as little as 10 minutes.

  • Avanafil, sold under the brand name Stendra, is an option that works in 15–30 minutes. It’s designed to target the body more precisely, reducing the chance of side effects while lasting up to 6 hours.

  • Daily tadalafil, the active ingredient in Cialis, stays active in your system every day when taken as a daily low-dose pill. It eliminates the need to plan doses around sex, making it a great option for those who want more flexibility.

Each of these alternatives has unique benefits, and a healthcare provider can help you choose the one that best suits your needs.

The hidden dangers of counterfeit ED medications

Counterfeit ED drugs often contain incorrect dosages, harmful contaminants, or undisclosed ingredients, putting users at risk of serious health complications.

Fake versions of sildenafil or tadalafil, are usually produced in unregulated facilities and can contain toxic substances like industrial solvents, printer ink, or even undeclared pharmaceuticals.

A 2019 outbreak in Singapore highlighted the dangers when counterfeit ED products laced with glibenclamide, a diabetes drug, caused a severe blood sugar drop and hospitalized over 150 people. The safest way to obtain ED medications is through a licensed healthcare provider or pharmacy.

To avoid these risks, stick to licensed providers and pharmacies. In the next section, we’ll show you exactly how to get legitimate, safe medication without the worry of counterfeit products.

How to get Viagra or sildenafil online

Buying Viagra or generic sildenafil online is a simple and straightforward process. Here’s how it typically works:

Step 1: Complete an online health assessment

Start by answering some questions about your medical history, current medications, and ED symptoms. This helps a licensed healthcare provider understand your situation and figure out the best treatment for you.

Step 2: Provider review A licensed healthcare provider will look over your answers and decide if Viagra, sildenafil, or another ED medication is a good fit. They might ask you a few follow-up questions to make sure they have all the details.

Step 3: Get your prescription If approved, your medication is sent right to your doorstep in discreet packaging. No awkward trips to the pharmacy—just safe, effective treatment delivered to you.

Step 4: Begin your treatment Take your medication as directed by your provider. Platforms like Ro provide follow-up support, so you can adjust your dosage or discuss any concerns as needed.

This process makes accessing ED treatments like Viagra and sildenafil simple, private, and efficient without requiring an in-person visit.

What happens if you take too much sildenafil?

Taking sildenafil exactly as prescribed is important for both its safety and effectiveness. Exceeding the recommended dosage can lead to serious complications.

Is it safe to take 100 mg of sildenafil?

For most people, 100 mg is the highest recommended dose. If this dose doesn’t work, taking more is not likely to improve its effectiveness, and it can instead increase the likelihood of side effects. Consult your healthcare provider to discuss alternative treatments or adjustments.

Can a man take 200 mg of sildenafil?

No, taking 200 mg of sildenafil is unsafe. At this dose, the risk of side effects can increase significantly—such as severe headaches, low blood pressure, dizziness, and painful erections that last a long time.

What happens if you take two sildenafil tablets in one day?

Taking sildenafil more than once in a 24-hour period can overstimulate the cardiovascular system, leading to dangerous complications such as severe hypotension, dizziness, or fainting. It can also increase the risk of prolonged side effects like visual disturbances or gastrointestinal discomfort.

Overdose symptoms may also include sudden changes in vision or hearing, severe low blood pressure, and in extreme cases, heart complications.

To stay safe, always adhere to your healthcare provider’s prescribed dosage and timing. If you feel your current dose isn’t effective, don’t self-adjust—reach out to your healthcare provider to explore alternative options.

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A short history of Viagra vs. sildenafil

In March 1998, the FDA approved the new medication under the name Viagra. As the first oral medication for ED, it was an instant success. Viagra became a household name, thanks to its effectiveness and widespread advertising campaigns that brought the “little blue pill” into the spotlight.

Sildenafil’s versatility didn’t stop there. In 2005, the FDA approved sildenafil under the brand name Revatio for treating pulmonary arterial hypertension (PAH), a condition involving high blood pressure in the lungs.

Pfizer’s patent for Viagra began to expire in 2012 outside the U.S., allowing other manufacturers to produce generic versions. In the U.S., generic sildenafil became available in 2017 after Pfizer’s exclusivity ended. Generic sildenafil makes ED treatment more affordable and accessible by offering the same active ingredient at a fraction of the price.

Bottom line

For those wondering, “Is sildenafil the same as Viagra?” the answer is that they’re chemically identical, but Viagra is marketed as a premium, branded option.

Both contain the same active ingredient, work the same way, and are equally effective at improving erections and enhancing sexual performance.

The only real difference lies in the price: Viagra, as a brand-name medication, is significantly more expensive, while sildenafil offers a more affordable option.

Ro makes it easy to get the ED treatment you need, whether you prefer genuine, branded Viagra® or the more affordable generic option, sildenafil. Ro offers generic sildenafil at $4 per dose, and brand-name Viagra costs $90 per dose. Both options are available in 25, 50, or 100 mg doses and contain the same active ingredient, sildenafil citrate.

And for those who don’t want to swallow pills or want something that acts faster––Ro Sparks is a 2-in-1 treatment combining the active ingredients in Viagra (sildenafil 55 mg) and Cialis (tadalafil 22 mg).

You can place it under your tongue for quicker absorption. It can help you get an erection in as little as 15 minutes and may keep you ready for sex for up to 36 hours—which is perfect for spontaneous moments. Sparks are $12 per dose with a monthly subscription plan.

You can complete an online visit and connect with a licensed US healthcare provider to discuss your options—all from the comfort of your home. If prescribed, your medication is delivered directly to your door in discreet packaging. It’s ED treatment, made simple and stress-free.

DISCLAIMER

If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

Sildenafil (Generic of Viagra)
Erectile Dysfunction

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

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Current version

January 09, 2025

Written by

Sonia Rebecca Menezes

Fact checked by

Raagini Yedidi, MD

About the medical reviewer

Raagini Yedidi, MD - Contributor Avatar

Raagini Yedidi, MD

Raagini Yedidi, MD, is an internal medicine resident and medical reviewer for Ro.

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