Viagra® vs. Sildenafil: What's the Difference?

If you’ve searched the web for information about ED medication, you’ve no doubt seen Viagra® mentioned alongside a drug called sildenafil. Given how often they’re interchanged, you might be wondering if there are any differences when it comes to sildenafil vs. Viagra.

Put simply, Viagra is the FDA-approved brand-name version of sildenafil, a prescription medication for ED. Sildenafil is the main active ingredient in Viagra. Like the store-brand salad dressing made with the same ingredients as its brand-name equivalent, sildenafil is just as good as the “little blue pill,” but cheaper.

So, is sildenafil Viagra? Yes — but there are notable distinctions. Keep reading to learn more about the similarities and differences between these drugs, and how to choose the best one for you.

Sildenafil citrate (often shortened to “sildenafil”) is the main ingredient in Viagra. After parent company Pfizer’s patent expired, other manufacturers were allowed to manufacture generic Viagra under the name of its active ingredient, sildenafil. The terms are pretty much interchangeable, the way you might say “Kleenex®” to refer to a tissue. The only real difference between the two medications for ED is how much they cost.

Viagra® is a well-known and widely used medication for treating erectile dysfunction (ED), one of the most common sexual dysfunctions in the world. Formulated as that iconic little blue pill, Viagra has the longest history of any FDA-approved ED treatment on the market today. Both generic sildenafil and Viagra work by increasing blood flow to your penis, making it easier for you to get and maintain an erection. 

Sildenafil belongs to a class of enzyme-inhibiting drugs called phosphodiesterase type 5 inhibitors, or PDE5 inhibitors. Like the others in its class, sildenafil works by relaxing the muscle tissue inside the walls of your blood vessels, allowing the vessels to dilate, and improving blood flow throughout some parts of your body — including your penis.

It's important to note that these erectile dysfunction medications aren't wonder drugs. They only work if you're sexually stimulated. But if you’ve got sexual stimulation and these pills, research shows that you have an effective, reliable erectile dysfunction treatment.

A Brief History of Viagra vs. Sildenafil

If you’re curious about the history of the brand and generic names, here’s the quick version:

• In 1996, Pfizer patented sildenafil. 

• Two years and many clinical trials later, in March of 1998, the new medication — now called Viagra — received approval from the Food and Drug Administration and hit the market as a prescription medication for the treatment of erectile dysfunction.

• As the first oral medication for ED, Viagra became incredibly popular. Large-scale TV ad campaigns made the little blue pill famous.

• In 2005, the FDA approved sildenafil under the brand name Revatio® for treating pulmonary arterial hypertension — more on this later.

• Pfizer’s patent on Viagra expired in 2012 for countries outside the U.S., allowing other brands to produce and market their own generic Viagra medications containing sildenafil. 

• Although Pfizer challenged the expired patent in the United States, sildenafil has since become widely available as a generic medication manufactured and marketed by various companies.

Viagra is brand-name sildenafil that’s FDA-approved for ED, and what is the active ingredient in Viagra? Sildenafil. But we suspect the question you really want to ask is whether one is made better, or safer — is generic sildenafil as good as Viagra for treating ED?

Although some manufacturers may use their own brand name, most generic sildenafil products are labeled simply as “sildenafil.” Regardless, they do the same thing, offer the same benefits, and have the same risk of side effects. 

Their primary difference is their price.

While a single tablet of Viagra is priced as high as $70 in the United States, generic drugs like sildenafil tablets are available for as little as $3 each when purchased online.

Even though the active ingredients are the same, if you’re switching from Pfizer’s brand-name Viagra to a generic form of sildenafil, it’s important to check that you’re purchasing tablets with a similar dosage to the one your healthcare provider prescribed.

International Generic Viagra Names

Sildenafil may also be sold under different brand names in other countries. Some of these Viagra generic names include:

• Figral and Mazzogran from Mexico

• Fildena from India

When it comes to drugs like Figral, Mazzogran, and Fildena vs. Viagra, they are all used for the same purpose: increasing blood flow to the penis. Their labels also state that these products contain sildenafil, so Mazzogran sildenafil 100mg should be equivalent to brand-name Viagra 100mg.

However, because these drugs have not been made in the U.S. and cleared by the FDA, it may be harder to assess the quality of their ingredients. Each country has its own set of regulations, and there’s always the chance the product you’re getting is not authentic if you buy it online from an international retailer.

If you’re in the U.S. and looking for a cheaper alternative to Viagra, it’s best to stick with FDA-approved sildenafil.

Viagra comes in three dosages: 25mg, 50mg, and 100mg. Most patients start at 50mg.

Sildenafil pills similarly come in 25mg, 50mg, and 100mg tablets. However, sildenafil can also come in 20mg when it is sold as the generic version of Revatio. Revatio is FDA-approved to treat a type of high blood pressure in the lungs (called pulmonary arterial hypertension, or PAH), but it can be prescribed off-label for ED.

So, is sildenafil 20mg the same as Viagra 25mg? While each tablet of generic Revatio is 20mg, when used for ED, you could be prescribed multiple tablets at once, making 40mg, 60mg, 80mg, and 100mg doses possible. Learn more about the difference between Revatio and Viagra on our blog. Sildenafil is also available in the United States as a liquid solution.

Your healthcare provider will tell you the specific dosage of brand-name Viagra or generic sildenafil that you should use if you’re prescribed this medication. 

Since brand-name Viagra tablets and generic sildenafil both contain the exact same active ingredient, you can expect identical results from a 25mg-100mg dose of Viagra (the typical doses used for erectile dysfunction) as you can the same dose of generic sildenafil.

Both Viagra and sildenafil work best when taken at least 30 minutes to an hour before sexual activity (and no more than four hours beforehand).  You can take Viagra or generic sildenafil with or without food, but should avoid taking either with a high-fat meal, as it can make both medications take longer to take effect in your body.

If you don’t experience any improvement in your erectile function after using Viagra or generic sildenafil, don’t simply take more of this medication. Instead, let your healthcare provider know — they may recommend adjusting your dosage or trying a different ED medication. Although sildenafil works similarly to other PDE5 inhibitors like vardenafil (Levitra), the two have different dosages. Vardenafil, for example, uses a lower dose, although not necessarily stronger than Viagra.

Since brand-name Viagra and generic sildenafil contain the same active ingredient and come in the same range of dosages, both medications can cause the same range of side effects. 

We’ve divided the side effects into two groups: common and rare. We’ve also included a note about serious drug interaction risks that you should seek to avoid and alert your healthcare provider to before taking sildenafil.

Common Side Effects of Viagra and Sildenafil

Common side effects of Viagra and generic sildenafil include:

• Heartburn

• Indigestion

• Headache

• Nosebleeds

• Nasal congestion

• Flushing

• Diarrhea

• Muscle aches and back pain

• Increased sensitivity to light

• Changes in your perception of color, such as a visible blue tinge or difficulty telling the difference between the colors blue and green

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 (a persistent, often painful erection lasting longer than four hours)

• Sudden blurred vision

• Loss of vision

• Loss of hearing

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

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

Viagra and Sildenafil Drug Interactions

Both Viagra and generic sildenafil can interact with other medications, including alpha-blockers, nitrates, and other medications used to treat hypertension (high blood pressure), heart disease, and other cardiovascular health issues.

As such, you’ll want to tell your healthcare provider if you’re taking any prescription or over-the-counter medications, or if you’ve had previous heart issues like angina, chest pain, or a heart attack.

Our complete guide to Viagra (sildenafil) side effects discusses the side effects and interactions listed above in more detail.

Minor differences in packaging and pill appearance aside, brand-name Viagra and its generic counterpart, sildenafil, are exactly the same medication. 

If you have erectile dysfunction, both medications should produce a noticeable boost to your sex life by improving your erections and sexual performance. The key difference, as we mentioned above, is price. While Viagra is relatively expensive, you can purchase generic sildenafil tablets at a much more affordable price.

In addition to sildenafil and Viagra, Hims offers access to other proven ED medications online including:

• Tadalafil (Cialis®): Tadalafil (Cialis) can provide relief from erectile dysfunction for up to 36 hours per dose

• Vardenafil (Levitra®): Vardenafil (Levitra): Offers relief from ED for slightly longer than sildenafil

• Avanafil (Stendra®): (Stendra): Works quickly and is less likely to cause certain side effects 

• Chewable ED meds: Hard Mints comes in discreet packaging and is made with the same active ingredients in Viagra® and Cialis® at different dosages

You can learn more about these medications in our complete guide to the best pills for treating erectile dysfunction or access FDA-approved ED medications with Hims online. Schedule a call with a healthcare professional today.