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A Complete Guide to Stendra (Avanafil) Side Effects

Kristin Hall, FNP

Medically reviewed by Kristin Hall, FNP

Written by Our Editorial Team

Last updated 7/05/2020

As much as 52 percent of men are affected by erectile dysfunction, making it by far the most common of the sexual performance issues men face.

Treatments for erectile dysfunction, or ED, have been available since the 1990s. Viagra was the first medication marketed specifically to treat ED, following its 1998 FDA approval. Cialis and Levitra, two similar medications, followed in 2003 with their FDA approvals.

Stendra, or avanafil, is the newest ED medication on the market. It was approved by the FDA in 2012 and offers several advantages over older medications, including a reduced risk of causing several common side effects.

While Stendra is less likely to cause side effects than older medications, a small percentage of men who use it could still experience certain side effects. We’ve listed these side effects below, along with study data on how frequently they occur and what you can do to manage them.

The Most Common Side Effects of Stendra (Avanafil)

In general, side effects are less common with Stendra than with older, first-generation erectile dysfunction medications. According to FDA data, the common side effects of Stendra occur at about one third the rate of the equivalent side effects of Viagra.

This means that if you often experience side effects from Viagra, Cialis or Levitra, Stendra may be a good alternative ED treatment for you.


Headaches are the most common side effect reported by men who use Stendra to treat erectile dysfunction. In trials carried out before Stendra gained FDA approval, 5.1 percent of men experienced headaches after taking 50mg of Stendra, the medication’s lowest effective dose.

At higher doses of 100 and 200mg, 6.9 percent and 10.5 percent of men reported experiencing headaches after using Stendra. Headaches were also reported as a side effect by men who were given a  non-therapeutic placebo, albeit at a rate of 1.7 percent.

In comparison, approximately 15 percent of men who use Cialis and 28 percent of men who use Viagra at the highest dose report headaches as a side effect.

Headaches from Stendra are caused by the effects of the medication on blood flow throughout your body. While Stendra primarily targets the penis, it can also cause blood vessel dilation in other parts of your body, resulting in a relatively mild headache.

This side effect normally passes on its own as avanafil, the active ingredient in Stendra, exits your body. To relieve the pain, you can take a normal dose of Tylenol (acetaminophen) while using Stendra without affecting the medication’s effectiveness.

If you get persistent headaches after using Stendra, talk to your doctor about adjusting your dosage. You can also implement the techniques in our guide to treating headaches from ED medication.

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Facial Flushing

Facial flushing is the second most common side effect reported by men who use Stendra. It affects 3.2 percent of men who use Stendra at the lowest 50mg dose, with 4.3 percent and 4 percent of men who use Stendra at doses of 100 and 200mg also affected.

In comparison, between 10 percent and 19 percent of men who use Viagra report flushing as a side effect, depending on the dosage used.

Like headaches, flushing from Stendra is caused by blood vessel dilation. If you’re prone to flushing, you may notice that your cheeks, nose, neck and chest become slightly redder for several hours after you take Stendra.

Just like other Stendra side effects, facial flushing fades away on its own as the total level of avanafil in your body declines. This is a side effect of all ED medications, meaning you might also be affected if you use Viagra, Cialis or Levitra instead of Stendra.

Nasal Congestion

Nasal congestion is a fairly common side effect of Stendra, affecting from 1.8 percent of men at the lowest 50mg dose and 2 percent to 2.9 percent of men at doses of 100mg and 200mg.

In comparison, up to 9 percent of men who use Viagra experience some degree of nasal congestion as a side effect.

Like other side effects, nasal congestion from Stendra is caused by the medications effects on your blood vessels. By dilating the smooth muscle within your sinuses, Stendra may cause you to get a mild stuffy or congested nose.

Nasal congestion from Stendra is sometimes accompanied by other cold symptoms, such as a mild swelling in your sinuses. As with other side effects, these typically fade away gradually as the concentration of avanafil in your body declines over the course of several hours.

Back Pain

Back pain is reported by a small percentage of men who use Stendra. Interestingly, this side effect appears to be more common in men who use the 50mg dose of the medication than in men who use higher doses (it’s reported by 3.2 percent of men at 50mg and just 1.1 percent at 200mg).

Like most side effects of Stendra, back pain is a common side effect of all ED medications. It occurs more frequently with older medications than with Stendra — up to 4 percent of men who use Viagra and 6 percent of men who use Cialis report it as a side effect.

This side effect typically fades away over the course of several hours as the concentration of avanafil in your body declines. Like with headaches, over-the-counter pain relief medications such as Tylenol (acetaminophen) are safe to use and often effective at treating this issue.

Less Common Side Effects of Stendra (Avanafil)

Stendra can also cause several less common side effects. These side effects occur in one to two percent of men who use Stendra as needed. As with the more common side effects listed above, most are relatively mild and pass on their own as the medication exits your body:

  • Upper respiratory infection (URI)

  • Bronchitis

  • Influenza

  • Sinusitis

  • Sinus congestion

  • Hypertension

  • Dyspepsia (indigestion)

  • Nausea

  • Conspiration

  • Skin rash

  • Dizziness

  • Arthralgia (joint pain)

  • Diarrhea

Due to its more specific action on the PDE5 enzyme, Stendra is less likely to cause side effects related to color vision than older medications such as Viagra. In multiple studies involving more than 1,000 participants carried out by the FDA, only one person reported vision-related issues.

Serious Side Effects of Stendra (Avanafil)

As a second-generation ED medication, Stendra is less likely to cause serious side effects than older medications of this type. For example, vision-related side effects appear to be significantly less common with Stendra than with older ED drugs, such as Viagra.

Despite this, it’s still possible for Stendra to cause some potentially serious side effects. These are exceptionally rare, affecting only a tiny percentage of patients. Potential severe side effects of Stendra include:

  • Priapism. Priapism is a painful, prolonged erection lasting for more than four hours. This is a rare side effect of all PDE5 inhibitors used to treat erectile dysfunction. If you have a painful, persistent erection after using Stendra, seek medical help immediately.

    Although priapism can sound scary, it only affects a tiny percentage of men who use ED medications. In total, only 93 cases of priapism were recorded in the entire year of 2007 (before Stendra was released), making this side effect exceptionally unlikely.

  • Vision issues. Although vision issues are less common with Stendra than with older ED mediations, they can still occur. After using Stendra, a small percentage of men may get vision-related issues such as vision loss and issues perceiving certain colors.

    If you experience vision issues after using Stendra, stop using the medication and talk to your doctor. Vision issues may potentially be a sign of nonarteritic anterior ischemic optic neuropathy (NAION) — a potentially serious eye problem.

  • Hearing issues. It’s possible, albeit extremely rare, for Stendra to cause hearing issues, such as a sudden loss of hearing or tinnitus. If you notice any hearing issues after using Stendra, stop using the medication and talk to your doctor.

Stendra (Avanafil) Drug Interactions

As a PDE5 inhibitor, Stendra can interact with some medications used to treat hypertension and other cardiovascular health conditions.

In particular, Stendra can interact with nitrates used to treat hypertension. Used together, these medications can lead to a sudden, significant drop in blood pressure that can result in fainting, heart attack and stroke.

If you are prescribed nitrates, do not use Stendra. This is a common side effect of all erectile dysfunction medications, meaning you should also not use Viagra (sildenafil), Cialis (tadalafil) and Levitra (vardenafil) if you are prescribed any nitrate medication.

Stendra can also interact with certain alpha-blockers and CYP3A4 inhibitors. Inform your doctor about all of the prescription medications you use before considering Stendra or similar drugs to treat erectile dysfunction.

Learn More About Stendra (Avanafil)

Are you considering Stendra as a treatment for erectile dysfunction? As a second-generation ED medication, Stendra is less likely to cause side effects than older drugs like Viagra, Cialis and Levitra. It also starts working faster and remains effective even if used with alcohol.

Our Stendra 101 guide goes into more detail on how Stendra works, the unique advantages it offers over older ED medications and how you can use it to treat ED and improve your sexual performance.

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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.

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