Drug vs. Drug

Stendra vs. Viagra: Differences, similarities, and which is better for you

Karen Berger medical writer and reviewer headshot By | February 3, 2020

Drug overview & main differences | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | FAQ

If you suffer from erectile dysfunction (ED), you are not alone. An estimated 15 to 30 million men in the United States experience ED. Stendra (avanafil) and Viagra (sildenafil) are two medications used in the treatment of ED. They belong to a group of FDA-approved prescription medications called phosphodiesterase-5 inhibitors (PDE5 inhibitors). Other drugs in this class of ED medications include Cialis (tadalafil) and Levitra (vardenafil).

PDE5 inhibitors work by increasing both the levels and activity of nitric oxide. By doing this, there is better blood flow to the penis, causing an erection. The medications also help to prolong erections and increase sexual satisfaction. It is important to note that PDE5 inhibitors work in conjunction with sexual stimulation.

What are the main differences between Stendra and Viagra?

Stendra and Viagra are both PDE5 inhibitors used in the treatment of erectile dysfunction.

Stendra is currently only available in a brand name only. The chemical name is avanafil, but the drug is not yet available as avanafil, only as brand-name Stendra.

Stendra should be taken as a 100 mg or 200 mg dose, as early as 15 minutes prior to sexual activity. It can also be dosed at 50 mg approximately 30 minutes before sexual activity.

Viagra should be taken approximately one hour prior to sexual activity. Whether you take Stendra or Viagra, only one dose should be taken in one day.

Regardless of the drug or dose, the medication should be accompanied by sexual stimulation in order to be effective. Either drug may be taken with or without food.

Main differences between Stendra and Viagra
Stendra Viagra
Drug class PDE5 inhibitor PDE5 inhibitor
Brand/generic status Brand Brand and generic
What is the generic name? Avanafil (but it is not yet available in generic) Sildenafil
What form does the drug come in? Tablet (50 mg, 100 mg, 200 mg) Tablet (25 mg, 50 mg, 100 mg)
What is the standard dosage? Example: one 100 mg tablet 15 minutes before sexual activity
OR
one 50 mg tablet approximately 30 minutes before sexual activity
*not to be taken more than once in a day
Example: one 50 mg tablet one hour prior to sexual activity but can range anywhere from 25 mg to 100 mg taken 30 minutes to 4 hours before sexual activity
*not to be taken more than once in a day
How long is the typical treatment? As needed As needed
Who typically uses the medication? Adult males Adult males

Conditions treated by Stendra and Viagra

Both Stendra and Viagra have only one official indication—the treatment of ED in men.  However, both drugs may be used off-label for Raynaud’s phenomenon. Viagra is sometimes used off-label to treat female sexual arousal disorder.

Condition Stendra Viagra
Erectile dysfunction Yes Yes
Raynaud’s phenomenon Off-label Off-label
Female sexual arousal disorder No Off-label
Treatment of pulmonary arterial hypertension (WHO Group I) in adults to improve exercise ability and delay clinical worsening No Yes, but not as Viagra. Only when prescribed as Revatio (or its generic sildenafil), in doses of 20 mg three times daily

Is Stendra or Viagra more effective?

A review of clinical studies concluded that Stendra was comparable in efficacy to Viagra, as well as other PDE5 inhibitors. The study also noted that Stendra is more favorable in terms of side effects and drug interactions, and has less of an effect on lowering blood pressure.

Another review of studies concluded that Stendra is safe and effective, but speculated an uncertainty for Stendra’s place in the market. This is because all PDE5 inhibitors are similar, and besides Stendra, all of them are available in generic, offering a significant money-saving advantage to the patient. The authors predicted that, “a new agent without such a long history may have difficulty finding a market share.”

The most effective medication for you should only be determined by your doctor, who can look at your medical condition(s), history, and other medications you take.

Coverage and cost comparison of Stendra vs. Viagra

There is a wide variation in regards to insurance coverage for Stendra or Viagra. Some insurance companies pay for them, and others do not. Some insurances have a limit on the quantity that you can fill, for example, your insurance may allow four tablets per month on an ED medication.

A standard prescription of #10 tablets of Stendra 100 mg (available in brand-name only) will cost about $680 with a SingleCare discount card.

A standard prescription of #10 tablets of sildenafil 50 mg (generic Viagra) tablets can range from $150-$300 depending on which pharmacy you use. Another cheaper alternative is to check out our partnership with Lemonaid Health where you can get Sildenafil for as little as $2 per pill.

Stendra Viagra
Typically covered by insurance? Coverage varies Coverage varies
Typically covered by Medicare Part D? No No
Standard dosage #10 tablets, 100 mg #10 tablets, 50 mg
Typical Medicare copay Varies (patients often pay out of pocket) Varies (patients often pay out of pocket)
SingleCare cost $680 $150+

Common side effects of Stendra vs. Viagra

Stendra and Viagra have many similar side effects, however, it is important to note that the frequency varies by dose. For example, 16% of patients taking Viagra 25 mg experienced headaches, but with a dose of 100 mg, 28% of patients experienced headaches.

With Stendra, the most common side effects are headache, flushing, nasal congestion, and back pain. The most common side effects of Viagra are headache, flushing, nasal congestion, and indigestion.

This is not a complete list of side effects. Consult your healthcare provider for a full list.

Stendra Viagra
   Side Effect Applicable? Frequency Applicable? Frequency
   Headache Yes 5.1-10.5% Yes 16-28%
   Flushing Yes 3.2-4.3% Yes 10-19%
   Nasal congestion Yes 1.8-2.9% Yes 4-9%
   Back pain Yes 1.1-3.2% Yes 3-4%
   Indigestion Yes 1-2% Yes 3-17%
   Dizziness Yes 1-2% Yes 3-4%
   Nausea Yes 1-2% Yes 2-3%

Source: DailyMed (Stendra), DailyMed (Viagra)

Drug interactions of Stendra and Viagra

Patients taking Stendra or Viagra should never take nitrate medications, such as nitroglycerin. The combination is contraindicated (should never be used together) because it could result in dangerously low blood pressure.

There are many drugs that, in combination with Stendra or Viagra, could cause blood pressure to decrease. These include alpha blockers (such as alfuzosin, terazosin, or tamsulosin), riociguat (a drug used to treat pulmonary arterial hypertension), and blood pressure medications. These drugs should only be used with Stendra or Viagra with caution, and with appropriate monitoring by your healthcare provider.

Drugs are metabolized with the help of enzymes, and a common one is the cytochrome P450 3A4 (CYP3A4) system. A drug that inhibits CYP3A4 can cause another drug to build up in the system, by inhibiting, or slowing down, how the other drug is processed. For example, if drug A inhibits drug B, you will get a buildup of drug B in your body, which could lead to increased side effects. Drugs can be strong inhibitors or moderate inhibitors.

Patients taking a strong 3A4 inhibitor should not take Stendra, and patients taking a moderate inhibitor should take no more than 50 mg, and only if approved by the doctor. Viagra should be started at the lowest dose of 25 mg when given with a strong 3A4 inhibitor. If taken with the protease inhibitor ritonavir, Viagra should be taken as 25 mg at least 48 hours apart.

Other drug interactions may occur; consult your healthcare professional for a full list of drug interactions.

Drug Drug Class Stendra Viagra
Nitroglycerin Nitrates Yes Yes
Riociguat Guanylate cyclase stimulator Yes Yes
Alfuzosin
Tamsulosin
Terazosin
Alpha blockers Yes Yes
Lisinopril
Amlodipine
Bystolic
Metoprolol
Losartan
Ramipril
etc.
Antihypertensives Yes Yes
Ketoconazole
Itraconazole, Clarithromycin
Ritonavir
Saquinavir
Nelfinavir
Indinavir
Atazanavir
Strong CYP 3A4 inhibitors Yes Yes
Erythromycin
Aprepitant
Diltiazem
Fluconazole
Fosamprenavir
Verapamil
Moderate CYP 3A4 inhibitors Yes Yes

Warnings of Stendra and Viagra

  • Cardiovascular health should be assessed before you take Stendra or Viagra. Certain patients may not be a candidate for Stendra or Viagra. Ask your doctor before taking Stendra or Viagra, if you have any problems with your heart or blood pressure.
  • Currently, it is recommended that Stendra or Viagra is not used in patients with recent cardiac events, such as a heart attack or stroke, patients with resting low blood pressure (less than 90/50 mmHg) or high blood pressure (more than 170/100 mmHg), and patients with unstable angina. Consult your doctor if you have heart or blood pressure problems.
  • Stendra or Viagra should not be used in patients who take nitrates such as nitroglycerin, or a guanylate cyclase stimulator such as riociguat, due to increased effects on lowering the blood pressure. Other medications in combination with Stendra or Viagra can affect blood pressure as well (see drug interaction chart).
  • Use Stendra or Viagra with caution in patients with anatomical deformation of the penis.
  • Occasionally, a prolonged erection (more than 4 hours), or priapism (a painful erection lasting longer than 6 hours) may occur. If an erection lasts longer than 4 hours, seek immediate medical attention. Failure to treat this condition immediately could result in permanent damage.
  • If you experience a sudden loss of vision or a sudden loss of hearing (which may be accompanied by dizziness or ringing in the ears), stop Stendra or Viagra and seek immediate medical attention.
  • Avoid substantial amounts of alcohol with Stendra or Viagra, because the combination could lead to an increased heart rate, lower blood pressure, dizziness, and headache.
  • Stendra or Viagra do not protect against sexually transmitted diseases, so other protective measures, such as condoms, should be used.
  • Because Stendra and Viagra are not indicated for women, there is no clinical data about the safety of these drugs in pregnancy. Therefore, it is not recommended to use Stendra or Viagra in pregnancy.

Frequently asked questions about Stendra vs. Viagra

What is Stendra?

Stendra (avanafil) is a PDE5 inhibitor that treats erectile dysfunction in men. Along with sexual stimulation, it helps increase blood flow to the penis, helping the patient achieve and maintain an erection. Currently, it is only available in brand name; there is no generic available yet.

What is Viagra?

Viagra (sildenafil) is a PDE5 inhibitor used to treat erectile dysfunction in men. It increases blood flow to the penis (in conjunction with sexual stimulation) so you can achieve and maintain an erection. Viagra is available in brand and generic.

You may have heard of a drug called Revatio used for ED, instead of Viagra. Revatio is another drug that contains sildenafil, the same ingredient in Viagra. Revatio is used to treat pulmonary arterial hypertension (PAH). Although Revatio is indicated only for PAH, it is often prescribed off-label for ED. Sometimes, when an insurance company does not cover Viagra, a doctor may prescribe Revatio instead, which is usually covered by insurance.

Are Stendra and Viagra the same?

Not exactly. They are very similar and are in the same category of drugs—PDE5 inhibitors. However, they do have some differences, outlined above.

Is Stendra or Viagra better? / Is Stendra more effective than Viagra?

Looking at trials, both drugs are very similar in efficacy, and both drugs are well-tolerated. One study noted that Stendra may have difficulty finding a place in the market due to its availability only as brand-name, with a much higher price than other PDE5 inhibitors. Viagra seems to be much more popular, but likely due to its lower price and time on the market.  It may sometimes take trial and error to find the medication that is best for you, and your doctor can help you decide.

Can I use Stendra or Viagra while pregnant?

Because neither drug is indicated for use in women, there are no studies to determine safety in pregnancy. Therefore, it is not recommended to use Stendra or Viagra while pregnant.

Can I use Stendra or Viagra with alcohol?

Alcohol can interfere with the body’s ability to achieve an erection; however, it might be okay in small quantities. Ask your medical provider for advice.

How long does Stendra last for?

Stendra begins to work as soon as 15-30 minutes after the medication is taken, and can last for up to six hours.

Is there a generic for Stendra?

Currently, there is no generic for Stendra. When there is a generic available, it will be called by its chemical name, avanafil.

Can you buy Stendra over the counter?

No. Stendra is only available by prescription in the United States. Viagra is also only available by prescription in the US.