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

Kelly Brown MD, MBA

Reviewed by Kelly Brown MD, MBA

Written by Geoffrey C. Whittaker

Published 06/24/2019

Updated 04/15/2024

Stendra® is a relatively new erectile dysfunction (ED) medication. It was developed in the 2000s and approved by the FDA in April 2012, while drugs like Viagra® have been used to treat ED since the 1990s.

One thing that helps set Stendra apart? Its active ingredient, avanafil, has fewer side effects than the active ingredients in older ED meds like Viagra, Cialis® and Levitra®. It can be a great alternative for anyone who experiences serious side effects with those other options. 

Of course, there are pros and cons to every ED treatment. Below, we’ve explained how Stendra works, what side effects it can cause and how it compares to older ED medications, so you can decide whether it might be right for you.

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Stendra (avanafil) is part of a class of erectile dysfunction medications known as phosphodiesterase type 5 or PDE5 inhibitors

Like Viagra® (sildenafil), Cialis® (tadalafil) and Levitra® (vardenafil), Stendra makes it easier to get and maintain an erection by increasing blood flow to the erectile tissue inside your penis.

And as with other ED medications, you won’t have to worry about getting random erections with Stendra. It only works if you’re sexually aroused, so you won’t get an erection unless you have some degree of mental or sensory sexual stimulation.

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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 penis.

  • Stendra is less likely to cause some side effects, such as headaches 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 differences between these treatments and explains which option is likely the best for you.

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As we’ve mentioned, Viagra isn’t the only prescription PDE5 inhibitor used to treat erectile dysfunction. And in addition to the other prescription medications, there are over-the-counter ED meds. Here’s how Stendra stacks up against all the other ED medications out there: 

  • Stendra has a quicker onset of action. Most first-generation erectile dysfunction medications start working in 30 to 60 minutes (or longer depending on your diet — more on that below), but Stendra typically starts working in 15 to 30 minutes. This means that you can take Stendra shortly before you plan to have sex without worries about your medication being effective.

  • Stendra is less affected by food than other ED medications. The FDA prescribing information for Viagra explains that fat can slow down the body’s absorption of it. In fact, having a big meal with a high fat content may delay Viagra’s effects by around one hour and potentially reduce its total concentration within the body. With Stendra, though, you’ll feel the full effects of the medication even if you take it after eating a large amount of food. Restaurant regulars and foodies, take note.

  • Stendra is less likely to cause certain side effects. Unlike most other medications for the treatment of erectile dysfunction, 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 generally safer to use with alcohol. While it’s not a license to drink irresponsibly, Stendra is generally safer and more effective after consuming alcohol than other prescription ED meds. More specifically, you can 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.

  • Stendra is safer than supplements. Unlike over-the-counter supplements, Stendra is an FDA-approved treatment option for ED. Phosphodiesterase-5 inhibitors have been well studied for their risks and safety, while supplements often have not.

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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, researchers reviewed five studies involving more than 2,200 men . They 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.

  • 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.

  • 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.

  • 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).

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.

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Stendra is currently available in tablet form and comes in three standard doses: 50mg, 100mg and 200mg — all of which should be taken between 15 and 30 minutes before sexual activity.

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 that out. 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.

Stendra pills in an average dose can last for up to six hours, giving you some flexibility around the precise time that you have sex after taking them. 

One important caveat with this second-generation ED treatment: You should not take Stendra more than once per day. If you need an erectile dysfunction medication that lasts for the entire day, you may want to consider using tadalafil (the active ingredient in Cialis), which lasts for up to 36 hours per dose.

Stendra is a prescription drug, meaning you can’t legally buy it without consulting with a licensed healthcare professional first. Because it’s a newer medication, Stendra is not currently available as a generic drug in the United States. 

Average prices fall around $53 per dose — much higher than Viagra, which can be as low as $3 per dose in generic form.

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

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

Like other ED medications, Stendra is easy to use. If you’re prescribed the 100mg or 200mg dose, 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, 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.

  • Take Stendra as needed. You can safely use it once every 24 hours. 

  • Depending on how well the medication works for you, your healthcare provider may suggest adjusting your dose to ensure you receive the full benefits. They’ll consider the severity of your symptoms and other factors, such as your age and general health. 

If you have questions, you can always ask your healthcare provider or check the label or guide that comes with Stendra pills.

For the best results, store your Stendra at room temperature away from moisture, heat and light.

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Stendra is a safe and effective medication for most people, but it isn’t free from side effects and drug interactions. 

Unsurprisingly, avanafil side effects are similar to those of other PDE5 inhibitors like 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.

Headache is by far the most common side effect of Stendra. 

Other common side effects of Stendra include: 

  • Flushing 

  • Nasal congestion 

  • Nasopharyngitis (cold symptoms) 

  • Back pain 

  • Loss of hearing

  • Dizziness

  • Blurred vision 

  • Retinitis pigmentosa (loss of vision) 

  • Prolonged erection or painful erection called priapism

Most side effects of avanafil 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. 

Like other ED medications, Stendra can cause a mild drop in your blood pressure levels while it’s 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 previously received treatment for before using Stendra or other ED medication.

Stendra can potentially interact with other medications, including those 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 such as nitroglycerin, alpha-blockers or amyl nitrate or butyl nitrate “poppers.”. 

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.

Generally speaking, a healthcare professional may suggest you avoid mixing Stendra with antifungal and other medications like:

  • Itraconazole

  • Ketoconazole

  • Clarithromycin

  • Erythromycin

  • Tamsulosin

  • Doxazosin

  • Riociguat

  • Indinavir

If you have a history of or are currently taking medications for Peyronie’s disease, leukemia, sickle cell anemia, heart problems or sexually transmitted diseases, you may get medical advice to avoid Stendra.

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Stendra (avanafil) is more than a decade newer than the original, first-generation PDE5 inhibitors used to treat erectile dysfunction, like Viagra (sildenafil), Cialis (tadalafil) and Levitra (vardenafil). It works largely the same way they do, improving blood flow to the penis to help men with ED get — and stay — hard. 

  • As a newer medication, Stendra has a more selective mechanism of action than other ED treatments, making it especially attractive 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 an ED medication that you can take just 15 to 30 minutes before sex. 

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

  • 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. 

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

  1. Dhaliwal, A. & Gupta, M. (2022, May 20). PDE5 Inhibitors. StatPearls. Retrieved from
  2. STENDRA- avanafil tablet. (2017, August). Retrieved from
  3. Erection Ejaculation: How It Occurs. (2020, November 27). Retrieved from
  4. CIALIS- tadalafil tablet, film coated. (2017, May). Retrieved from
  5. VIAGRA- sildenafil citrate tablet, film coated. (2017, August). Retrieved from
  6. Wang, H., et al. (2014, August). The effectiveness and safety of avanafil for erectile dysfunction: a systematic review and meta-analysis. Current Medical Research and Opinion. 30 (8), 1565-1571. Retrieved from
  7. Zhao, C., et al. (2012, December). Efficacy and safety of avanafil for treating erectile dysfunction: results of a multicentre, randomized, double-blind, placebo-controlled trial. BJU International. 110 (11), 1801-1806. Retrieved from
  8. Seftel, A.D. (2004, April). Phosphodiesterase type 5 inhibitor differentiation based on selectivity, pharmacokinetic, and efficacy profiles. Clinical Cardiology. 27 (4 Suppl 1), I14-I19. Retrieved from
  9. Mulhall, J.P., et al. (2013, June). A phase 3, placebo controlled study of the safety and efficacy of avanafil for the treatment of erectile dysfunction after nerve sparing radical prostatectomy. The Journal of Urology. 189 (6), 2229-2236. Retrieved from
Editorial Standards

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. See a mistake? Let us know at [email protected]!

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.

Kelly Brown MD, MBA
Kelly Brown MD, MBA

Dr. Kelly Brown is a board certified Urologist and fellowship trained in Andrology. She is an accomplished men’s health expert with a robust background in healthcare innovation, clinical medicine, and academic research. Dr. Brown was previously Medical Director of a male fertility startup where she lead strategy and design of their digital health platform, an innovative education and telehealth model for delivering expert male fertility care.

She completed her undergraduate studies at University of North Carolina at Chapel Hill (go Heels!) with a Bachelor of Science in Radiologic Science and a Minor in Chemistry. She took a position at University of California Los Angeles as a radiologic technologist in the department of Interventional Cardiology, further solidifying her passion for medicine. She also pursued the unique opportunity to lead departmental design and operational development at the Ronald Reagan UCLA Medical Center, sparking her passion for the business of healthcare.

Dr. Brown then went on to obtain her doctorate in medicine from the prestigious Northwestern University - Feinberg School of Medicine and Masters in Business Administration from Northwestern University - Kellogg School of Management, with a concentration in Healthcare Management. During her surgical residency in Urology at University of California San Francisco, she utilized her research year to focus on innovations in telemedicine and then served as chief resident with significant contributions to clinical quality improvement. Dr. Brown then completed her Andrology Fellowship at Medical College of Wisconsin, furthering her expertise in male fertility, microsurgery, and sexual function.

Her dedication to caring for patients with compassion, understanding, as well as a unique ability to make guys instantly comfortable discussing anything from sex to sperm makes her a renowned clinician. In addition, her passion for innovation in healthcare combined with her business acumen makes her a formidable leader in the field of men’s health.

Dr. Brown is an avid adventurer; summiting Mount Kilimanjaro in Tanzania (twice!) and hiking the incredible Torres del Paine Trek in Patagonia, Chile. She deeply appreciates new challenges and diverse cultures on her travels. She lives in Denver with her husband, two children, and beloved Bernese Mountain Dog. You can find Dr. Brown on LinkedIn for more information.

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