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Stendra (Avanafil) 101: How it Works, Side Effects & More

Katelyn Hagerty FNP

Medically reviewed by Katelyn Hagerty, FNP

Written by Our Editorial Team

Last updated 8/25/2022

Stendra® (avanafil) is a PDE5 inhibitor medication used to treat erectile dysfunction (ED). Like Viagra® (sildenafil), Cialis® (tadalafil) and Levitra® (vardenafil), Stendra makes it easier to get and maintain an erection if you suffer from erectile dysfunction.

A relatively new ED medication, Stendra was developed throughout the 2000s and approved in April 2012 by the FDA. This makes it far newer than ED drugs like Viagra, which have been in use by men since the 1990s to help treat ED problems.

Because of its newer formula, Avanafil, the active ingredient in Stendra, has fewer side effects than the active ingredients in older ED medications like Viagra, Cialis and Levitra.

Below, we’ve explained what Stendra is and how it’s used to treat erectile dysfunction. We’ve also looked at some of the key advantages Stendra offers compared to older ED medications, from its slightly longer-than-average half-life to its lower risk of causing certain side effects.

What is Stendra (Avanafil)?

Stendra is an erectile dysfunction medication. It’s part of a class of medications referred to as PDE5 inhibitors, which work by increasing blood flow to the erectile tissue located inside your penis.

By improving blood flow to your penis, Stendra makes it easier to get and maintain an erection when you feel sexually aroused.

To understand how medications like Stendra works, it’s important to quickly go over the basics of how you get an erection in the first place.

Erections are all about good blood flow. When you feel sexually aroused, your nervous system sends a signal to the tissue near your penis, causing the blood vessels that allow blood to flow to your penis to become wider.

As blood flows into your penis, the corpora cavernosa -- a pair of sponge-like bodies of erectile tissue inside your penis -- start to expand, causing your penis to become larger and firmer.

This process reverses after you reach orgasm and ejaculate, with blood flowing out of the soft tissue inside your penis and your erection becoming flaccid. 

Like other ED medications, Stendra won’t cause you to randomly get erections. Instead, it only makes it easier to get an erection if you’re already sexually aroused. This means you won’t get an erection unless you have some degree of mental or sensory sexual stimulation.

Stendra is currently available in tablet form and comes in a variety of doses. The most common doses are 50mg, 100mg and 200mg, all of which are intended for use 15 to 30 minutes prior to sexual activity.

A typical dose of Stendra lasts for up to six hours, allowing you to have some flexibility about the precise time that you have sex after using the medication. 

As a second-generation ED medication, Stendra has several differences from older ED pills like Viagra®. These include a fast onset of action (the amount of time required for the medication to start working) and a reduced risk of certain side effects.

We’ve discussed these and other information about using Stendra to treat erectile dysfunction in more detail in the sections below.

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Is Stendra Available as a Generic Medication?

Stendra is a new, second-generation erectile dysfunction medication that was only approved by the FDA in 2012. Because it’s a new medication, Stendra is not currently available as a generic drug in the United States. 

In some other countries, Stendra is marketed under the brand name Spedra. Spedra contains the same active ingredient as Stendra (avanafil in a dose of either 50, 100, or 200mg) and has the same benefits as a treatment for ED.

Although Stendra isn’t available as a generic drug just yet, several older medications for ED are sold as generics. These include sildenafil (the active ingredient in Viagra), tadalafil (Cialis®) and vardenafil (Levitra®). 

Where Can You Buy Stendra?

Stendra is a prescription medication, meaning you can’t legally buy it without first consulting with a licensed healthcare professional. 

If you’re curious about using Stendra, you may be able to get a prescription by talking with your primary care provider or scheduling an appointment with a urologist (a doctor that specializes in male reproductive health).

You can also receive a prescription and purchase Stendra online. We offer Stendra online after a medical consultation via an online assessment. If appropriate, you’ll receive a prescription for Stendra and be able to purchase medication online with discreet home delivery.

If you want to know more about the price, you can read our blog on how much Stendra costs.

What’s the Most Effective Dose of Stendra?

Stendra comes in three standard dosages, ranging from 50mg to 200mg. The suggested initial dosage of Stendra is 100mg, which should be taken between 15 and 30 minutes before sexual intercourse.

Because erectile dysfunction can vary in severity, your healthcare provider will choose the right dose of Stendra for you based on the severity of your symptoms, your age, your general health and other factors.

Like with other ED medications, it may take some time to work out the correct dose of Stendra for you. Your healthcare provider may recommend adjusting your dosage if you still find it hard to get an erection after using Stendra, or if you have severe or persistent side effects.

How Frequently Can You Take Stendra?

You should not take Stendra more than once per day. If you need an ED treatment that lasts for the entire day, you may want to consider using a long-acting-acting medication such as tadalafil (the active ingredient in Cialis), which lasts for up to 36 hours per dose.

How is Stendra Different From Viagra?

Although Stendra and Viagra are both designed to treat erectile dysfunction, there are several key differences between the two medications:

  • Stendra is more selective than Viagra, meaning it more specifically targets the PDE5 enzyme responsible for regulating blood flow to the erectile tissue of the penis.

  • Stendra is less likely to cause some side effects, such as headache and facial flushing, than Viagra.

  • Stendra typically starts working faster than Viagra and is less affected by factors such as your consumption of food and alcohol.

  • Stendra has a slightly longer half-life than Viagra, meaning it stays effective for a longer period of time after you take it.

Our Stendra vs. Viagra guide goes into more detail on the main differences between these two treatments and explains which option is likely the best for you.

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How is Stendra Different From Other ED Medications?

Stendra was developed throughout the 2000s and in 2012 gained approval from the FDA. As such, it’s the newest erectile dysfunction medication on the market. In comparison, Viagra was approved by the FDA in 1998, followed by Cialis and Levitra in 2003.

This means that Stendra is more than a decade newer than the original, first generation PDE5 inhibitors used to treat erectile dysfunction.

As a newer medication, Stendra offers several advantages over other drugs available to treat erectile dysfunction, including a quicker onset of action and a reduced risk of causing certain adverse effects.

We’ve discussed these differences below and explained why they may make Stendra a better choice for you.

Stendra Works Faster Than Older ED Medications

Most first-generation medications for erectile dysfunction start working in 30 to 60 minutes. In certain cases, such as after eating a large meal with a high fat content, it may take even longer for older ED medications to become effective.

As a newer medication for the treatment of erectile dysfunction, Stendra starts working rapidly, typically in 15 to 30 minutes. This means that you can take Stendra shortly before you plan to have sex without any worries about your medication being effective.

Stendra Lasts for Longer than Viagra

While Stendra isn’t as long lasting as tadalafil or brand-name Cialis, a regular dose of Stendra lasts for significantly longer than Viagra. On average, a normal dose of Stendra provides relief from erectile dysfunction for up to six hours.

Combined with Stendra’s rapid onset of action, this makes it easier to time your sexual activity around Stendra without having to pay close attention to the time you take your medication.

Stendra is Less Likely to Cause Some Side Effects

Stendra is more selective than other PDE5 inhibitors, which means it’s less likely to cause some side effects.

Unlike most other medications for ED, which target multiple PDE enzymes, Stendra is designed to specifically target the PDE5 enzyme that regulates blood flow to the erectile tissue inside your penis. 

This means that it has less of an effect on the enzymes PDE1, PDE3, PDE6 and PDE11, which helps to limit its side effect risk.

Stendra is Less Affected by Food Than Other ED Medications

First-generation ED treatments often take longer to start working, or are less effective, if you’ve eaten a large, high-fat meal before using them.

For example, the FDA prescribing information for Viagra explains that meals that are high in fat can slow down the body’s absorption of Viagra, which may delay its effects by around one hour and potentially reduce its total concentration within the body. 

Stendra is less affected by your food intake than other ED medications, meaning you’ll feel the full effects of the medication even if you take it after eating a large amount of food.

This means that Stendra may be a better choice for you if you often need to use ED medication after eating dinner or any other meal.

Stendra is Generally Safe to Use With Alcohol

Compared with first-generation ED treatments, Stendra is generally safer and more effective at treating erectile dysfunction if you have consumed alcohol. 

Although you’ll still need to limit your alcohol consumption if you plan to use Stendra, it’s okay to have up to three servings of alcohol without significantly increasing your risk of side effects from Stendra.

Consuming more alcohol than this may increase your risk of developing hypotension (low blood pressure) and other alcohol-related side effects while using Stendra.

How Effective is Stendra (Avanafil)?

Although Stendra is a relatively new medication, there are already several studies that show it’s highly effective at treating erectile dysfunction.

In a clinical review of avanafil (the active ingredient in Stendra) from 2014, five studies involving more than 2,200 men were reviewed to assess the medication’s results.

The researchers found that avanafil is highly effective at improving International Index of Erectile Function-Erectile Function (IIEF-EF), a score used to assess erection problems. The men who received the medication showed improvements at all doses, from 50mg to 200mg.

As you might expect, avanafil was most effective at the highest 200mg dose. Unlike many other ED medications, which are more likely to cause side effects at higher doses, the largest dose of avanafil did not appear to significantly increase the risk of the men experiencing side effects.

In a study published in 2012, researchers found that avanafil was “effective and well-tolerated” as a treatment for ED. The men involved in the study who used avanafil showed a significant improvement in IIEF score at a dose of either 100mg or 200mg.

Finally, in clinical trials for avanafil, researchers stated that the drug "demonstrated statistically significant improvement in all three primary efficacy variables” related to erectile function.

These trials involved more than 600 men affected by some degree of erectile dysfunction, with ages ranging from 23 to 88 years.

In short, avanafil works very well as a treatment for erectile dysfunction, with studies finding that it produces significant, measurable improvements in erection quality for men of all ages who are affected by ED. 

How to Use Stendra (Avanafil)

Like other ED medications, Stendra is easy to use. To use Stendra, simply take the tablet 15 to 30 minutes before you plan to have sex.

If you’re prescribed a lower dose of Stendra, such as the 50mg tablet, it’s recommended to use the medication at least 30 minutes before sexual activity. This allows your body enough time to fully absorb the medication’s active ingredient.

It’s okay to take Stendra on an empty stomach or with food. Stendra is safe to use after drinking alcohol, although you should limit your alcohol consumption to a maximum of three servings (for example, three glasses of wine or beer) to avoid increasing your risk of side effects.

You can safely use Stendra a maximum of once per day. Depending on how well the medication works for you, your healthcare provider may suggest adjusting your dose to ensure you receive the full benefits from the medication.

Stendra is a prescription medication, meaning you’ll need to speak with your healthcare provider and receive a prescription before you can purchase and use it. 

Your healthcare provider will provide an appropriate dosage based on your symptoms and other factors, such as your age and general health.

Side Effects of Stendra (Avanafil)

Stendra is a safe and effective medication for most people. However, although it’s less likely to cause side effects than other ED medications, it can still cause issues, including unwanted side effects and drug interactions. 

Because Stendra functions in a similar way to other PDE5 inhibitors, its side effects are similar to those of sildenafil (Viagra) and tadalafil (Cialis). However, the overall rate of certain adverse effects is generally lower due to Stendra’s more selective action within the body.

Common side effects of Stendra include: 

  • Headache. Headache is by far the most common side effect of Stendra. In clinical trials of Stendra, 5.1 percent of men experienced this side effect at 50mg (the lowest dose of Stendra), with 10.5 percent of men reporting headaches at 200mg (the highest dose).

    Headaches from Stendra and related ED medications are believed to be caused by the effects of these drugs on blood flow.

  • Flushing. Facial flushing is another common side effect of Stendra, affecting between 3.2 and percent and 4.3 percent of users. Like headaches, flushing is likely related to the effects of avanafil on blood flow.

  • Nasal congestion. Between 1.8 percent and 2.9 percent of men who use Stendra report some degree of nasal congestion after using this medication. Like other adverse effects of Stendra, this is likely caused by dilation of blood vessels.

  • Nasopharyngitis (cold symptoms). Between 0.9 percent and 3.4 percent of men who use Stendra develop cold-like symptoms, including nasopharyngitis (cold-like swelling in the nasal passages).

  • Back pain. Mild, temporary back pain affects 1.1 percent to 3.2 percent of men who use Stendra. Like other side effects of Stendra, back pain is a common adverse effect of all oral medications for ED.

Most side effects of Stendra are mild and transient. It’s normal for side effects to gradually fade away as Stendra stops working. Make sure to inform your healthcare provider if you notice any severe or persistent side effects while using Stendra. 

Stendra and other ED medications can cause vision and hearing issues, including sudden loss of hearing, tinnitus (ringing in one or both ears), dizziness, loss of vision, blurred vision or other changes in your ability to see accurately.

Stendra’s more selective effects on the PDE5 enzyme mean it doesn’t cause certain side effects that are common in older medications.

For example, up to 11 percent of men who use Viagra at the highest 100mg dose develop vision problems such as decreased vision or sudden vision loss, compared to less than one percent of Stendra users.

Although highly uncommon, Stendra and other medications for ED can also result in prolonged, painful erections called priapism. 

If you develop a painful or prolonged erection after using Stendra, it’s important to seek medical attention as soon as possible.

Like other ED medications, Stendra can cause a mild drop in your blood pressure levels while it is active in your body. As such, Stendra isn’t recommended for people with low blood pressure (hypotension), or the following heart conditions:

  • Unstable angina (chest pain or discomfort)

  • Hypertension (high blood pressure)

  • Congestive heart failure

  • Previous stroke or myocardial infarction (heart attack)

  • Previous coronary revascularization procedure

  • Life-threatening heart arrhythmia

It’s important to inform your healthcare provider about any medical issues you currently have or for which you have previously received treatment before using Stendra or other ED medication.

Stendra Drug Interactions

Stendra can potentially interact with other medications, including medications used to treat high blood pressure, heart disease and other cardiovascular health conditions.

More specifically, Stendra can cause a sudden, potentially dangerous drop in blood pressure if it’s used with nitrates and other medications for angina, high blood pressure and other cardiac health issues.

Stendra can also interact with other medications, including alpha blockers and medications that act as enzyme CYP3A4 inhibitors.

If you’re prescribed any type of nitrate, or if you use recreational drugs such as amyl nitrate or butyl nitrate “poppers,” you should not use Stendra. 

To reduce your risk of developing drug interactions, make sure to tell your healthcare provider about all medications you currently use or have recently used before you begin treatment with Stendra.

Can You Use Stendra With Alcohol?

Although Stendra shouldn’t be taken after heavy alcohol drinking, it’s generally alright to drink a small amount of alcohol while you’re using Stendra.

You can safely consume up to three standard servings of alcohol (for example, three glasses of wine or beer, or three shots of hard liquor) with Stendra, all without reducing the effectiveness of Stendra as a treatment for ED or significantly increasing your risk of side effects.

Is There a Minimum Age for Stendra?

Like sildenafil, tadalafil and other medications for ED, Stendra can be safely used by men of all ages with erectile dysfunction, including men in their 20s and 30s. 

Although erectile dysfunction becomes more common with age, it has the potential to affect men of all ages. This can make Stendra a useful treatment option if you’re affected by ED, regardless of your age.

Is Stendra Effective for Men Who’ve Had Prostate Surgery?

Yes. Stendra is one of several ED medications that are safe and effective for men who’ve had a prostatectomy or other prostate surgery.

In a study published in the Journal of Urology in 2013, experts stated that Stendra was “effective and well tolerated in improving erectile function” among men who had undergone prostatectomy (surgery to remove part or all of the prostate gland). 

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The Bottom Line on Stendra for Erectile Dysfunction

Stendra is one of several FDA-approved medications for treating erectile dysfunction. As a new medication, it has a more selective mechanism of action than other ED treatments, making it an option worth considering if you’re prone to side effects from drugs like sildenafil (Viagra).

Because Stendra is fast acting, it’s also a good option if you need a medication for ED that you can take just 15 to 30 minutes before sex. 

We offer Stendra as part of our selection of erectile dysfunction treatments, following an online consultation with a healthcare provider who will determine if a prescription is appropriate. 

Interested in finding out more about treating ED? Our guide to the most common treatments for erectile dysfunction goes into more detail about your options, including the medications that are currently available to improve your erections and sexual function. 

You can also learn more about overcoming sexual dysfunction through healthy daily habits and lifestyle changes in our detailed guide to naturally protecting your erection

9 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.

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  5. 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
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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.