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

Viagra® is a well-known and widely used medication for treating erectile dysfunction (ED), with the longest history of any FDA-approved ED treatment on the market today.

If you’ve searched for information about ED medication before, you’ve no doubt seen Viagra mentioned alongside a drug called sildenafil. And you might be wondering if there’s a difference between the two medications.

But while these two medications might have different names, they’re actually the same active ingredient.

Viagra vs. Generic Sildenafil

Sildenafil citrate is the generic version and active ingredient of Viagra. It works just like its Pfizer-branded big brother Viagra — just at a lower cost per pill because Pfizer no longer holds exclusive rights to the formula.

Generic sildenafil and Viagra work by increasing the level of blood flow to your penis, making it easier for you to get an erection. 

Sildenafil is the active ingredient in both of these medications and belongs to a class of enzyme-inhibiting drugs called phosphodiesterase-5 inhibitors, or PDE5 inhibitors. 

Sildenafil works by relaxing the muscle tissue inside the walls of your blood vessels, improving blood flow throughout many 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.

Pfizer patented sildenafil in 1996. 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 went on sale as a prescription medication used to treat erectile dysfunction.

As the first oral medication for erectile dysfunction, Viagra became incredibly popular. Its blue color and diamond shape earned it the nickname the “little blue pill” and large-scale TV ad campaigns made it a medication that just about everyone knew about.

Pfizer’s patent on Viagra expired in 2012 for countries outside the US, 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 that is manufactured and marketed by a range of different companies.

Although some manufacturers may use their own brand name, most generic sildenafil products are labeled simply as “sildenafil.”

Is There Any Difference Between Viagra and Sildenafil?

Sildenafil and Viagra are identical drugs. They do the same thing, offer the same benefits and come with the same risk of side effects. 

In fact, 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 there’s no difference in active ingredients, 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.

Sildenafil vs. Viagra Dosage

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

Sildenafil pills, meanwhile, come in 20mg tablets, but can be prescribed in different dosages, up to 100mg. It’s 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) to the same dose of generic sildenafil.

Both Viagra and sildenafil work best when taken within 30 minutes to an hour before sexual activity. 

You can take Viagra or generic sildenafil with or without food, but should avoid taking either with a high-fat meal — it can make both medications less effective.

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.

Sildenafil is also sold under the brand name Revatio®. This version of the medication contains an identical active ingredient to Viagra and generic sildenafil, but is used as a treatment for pulmonary arterial hypertension, rather than for ED. Learn more about the difference between Revatio® and Viagra on our blog.

Side Effects of Viagra vs. Sildenafil

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

Common Side Effects of Viagra vs. Sildenafil

Common side effects of Viagra and generic sildenafil include:

• Heartburn

• Indigestion

• Headache

• Nosebleeds

• Nasal congestion

• Flushing

• Diarrhea

• Muscle aches

• Increased sensitivity to light

• Numbness, or a burning or tingling sensation in your arms, legs, hands or feet

• 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 vs. Sildenafil

In rare cases, Viagra and generic sildenafil may cause serious side effects, such as priapism (a persistent, often painful erection), sudden blurred vision, loss of vision or feelings such as lightheadedness and dizziness brought on by low blood pressure.

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.

Sildenafil vs. Viagra: Which One Is Right For Me?

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

If you have erectile dysfunction, both medications should produce noticeable improvements in 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, we offer other proven ED medications online including:

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

• Vardenafil(Levitra®) offers relief from ED for slightly longer than sildenafil.

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

You can learn more about these medications in our complete guide to the best pills for treating erectile dysfunction or access our selection of FDA-approved ED medications online.