Sildenafil 20 mg: Is It the Right Dose for ED?

When it comes to penises, size isn’t everything. But the dosage size of erectile dysfunction medications? That’s something worth paying attention to.

Sildenafil citrate is a generic drug and the active ingredient in some prescription meds. It’s most popularly known as Viagra® and is used for treating erectile dysfunction (ED). Sildenafil is also sold as Revatio®, a medication marketed for the treatment of pulmonary arterial hypertension.

Depending on your health needs, your dosage of Viagra might be 25 mg (milligrams), 50 mg, or 100 mg. While 20 mg sildenafil tablets do exist, they’re usually prescribed for pulmonary hypertension, not erectile dysfunction. 

 What Is Sildenafil 20 mg Prescribed For?

Most people assume they know what Viagra does — it causes erections, right? While this is true, a few uses of sildenafil extend beyond improving sexual activity. 

Besides being sold as Viagra, sildenafil is the active ingredient in Revatio, a brand-name drug. Revatio is approved by the U.S. Food and Drug Administration (FDA) for treating pulmonary hypertension, a type of high blood pressure affecting arteries in the lungs and the right side of the heart. Revatio can prevent pulmonary hypertension from worsening.

At the moment, 20-mg Viagra does not exist — but you can get Revatio in a 20-mg tablet. While 20-mg sildenafil might improve erectile function, it’s mainly prescribed for pulmonary hypertension.

Sildenafil may also be used off-label to treat:

  • Raynaud’s phenomenon (narrowing blood vessels in the extremities)

  • Female sexual arousal disorder

  • Mountain sickness (altitude-induced hypoxemia)

Sildenafil has a variety of uses because it’s a phosphodiesterase type 5 (PDE5) inhibitor. PDE5 inhibitors are medications that improve blood flow to certain tissues by widening the blood vessels. This means blood can flow into your penis, allowing you to have a decent erection.

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Common Sildenafil Doses 

Viagra is available in dosages of 25 mg, 50 mg and 100 mg. At present, 100-mg sildenafil is the highest dosage approved by the FDA. Revatio is available in 20-mg tablets. 

There’s no one-size-fits-all solution when it comes to the ideal sildenafil dosage. Your dosage will depend on your unique health needs and the reason you’re taking the medication.

You might assume a higher dosage of sildenafil leads to a firmer erection or better sexual performance, but this isn’t always the case. In fact, taking too much sildenafil can lead to some serious side effects. 

It’s best to stick with the dosage recommended by the healthcare professional who prescribed the medication. If your current dose isn’t working as well as you hoped, make an appointment with your provider and ask if you can revisit your dosage or explore other treatment options for erectile dysfunction.

Effectiveness of Sildenafil 20 mg for Erectile Dysfunction 

To get the best results from Viagra, it’s important to take the right dosage. 

As mentioned, 20-mg sildenafil is FDA-approved for pulmonary hypertension, not erectile dysfunction. If you take a 20-mg dose of sildenafil, it might improve your erections. But in most cases, a larger dose is needed to treat ED.

Although Viagra can come in as small a dose as 25 mg, the 50-mg tablets are usually the starting dose. If you experience uncomfortable side effects, your dosage could decrease to 25 mg. Patients older than 65 and those with kidney or liver problems may start on a 25 mg dose.

Viagra is considered an effective treatment for erectile dysfunction — but its efficacy depends on the dosage. In clinical trials, 63 percent of participants who took 25-mg sildenafil reported an improvement in their erections, compared to 74 percent of those who took 50 mg and 82 percent of those who took 100 mg.

With that said, other erectile dysfunction treatments — like tadalafil (Cialis®) and vardenafil (Levitra®) — are available in a 20-mg dosage. 

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Sildenafil 20 mg Side Effects

Whether you’re experiencing poor erectile function or have a cardiovascular condition, sildenafil can drastically improve your symptoms.

The medication is generally safe, and research suggests it won’t cause any long-term health issues. But that doesn’t mean it’s completely without risks or side effects.

Common side effects of sildenafil include:

  • Headaches 

  • Flushing

  • Abdominal pain

  • Back pain

  • Chest pain (angina)

  • Blurred vision

  • Muscle pain

  • Nausea

  • Dizziness

  • Rash

  • Nasal congestion 

  • Priapism (prolonged, painful erection)

If you experience priapism or any other serious adverse effects — like shortness of breath, irregular heartbeat or loss of vision — seek emergency medical attention. 

Sildenafil might also be dangerous for people with a history of certain medical conditions, including:

  • Allergic reactions to Viagra or any PDE5 inhibitor

  • Blood problems like hemophilia, leukemia or sickle cell anemia 

  • Conditions affecting penis shape, like Peyronie’s disease or a curved penis

  • Eye problems, such as retinitis pigmentosa, vision loss or NAION (non-arteritic anterior ischemic optic neuropathy)

  • Heart problems (e.g., having had a heart attack or stroke)

  • High or low blood pressure  

  • Liver disease 

  • Kidney disease

  • Peptic ulcers

There are a couple of sildenafil drug interactions you need to look out for too. An interaction is when one drug, like sildenafil, causes a negative reaction when mixed with another medication, supplement or substance. 

Possible sildenafil interactions include:

  • Other PDE5 inhibitors, including erectile dysfunction medications like tadalafil (Cialis), avanafil (Stendra®) or vardenafil (Levitra® or Staxyn®) 

  • Nitrates, such as nitroglycerin (Nitrostat® or NitroMist®), isosorbide mononitrate and isosorbide dinitrate (Isordil®) 

  • Blood pressure drugs and alpha-blockers

  • Poppers (recreational drugs containing amyl nitrite and other nitrates)

Sildenafil may also have minor interactions with the following substances:

  • Certain antifungal drugs, such as ketoconazole and itraconazole 

  • Some antibiotics, like ciprofloxacin, erythromycin and clarithromycin (Biaxin®)

  • HIV protease inhibitors, like saquinavir mesylate (Invirase®) and ritonavir (Norvir®) 

If you’ve been prescribed any of the above medications, it’s a good idea to ask a healthcare professional whether you can safely take them with sildenafil.

Also, while you can mix Viagra with alcohol, it’s a good idea to pace yourself and only have one or two drinks. Combining the two could lead to a sudden decrease in blood pressure, which can be dangerous.  

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Is 20-mg Sildenafil Right for Me? 

Erectile dysfunction is just the tip (heh) of the iceberg when it comes to sildenafil’s potential. The dosage of sildenafil you use will depend on whether you’re taking it for erectile dysfunction, a cardiovascular condition or another issue.

  • A 20-mg dose of sildenafil is usually prescribed for pulmonary hypertension. If you’re curious about using sildenafil for erectile dysfunction, a different dosage might be more suitable.

  • For ED, 50 mg is the starting sildenafil dosage. Though it can be increased or decreased as needed, licensed prescribers usually start patients on a 50-mg tablet.

  • There are some alternatives. If the side effects of sildenafil are putting you off, or if it’s just not working as well as you’d hoped, other erectile dysfunction treatments may be more helpful. Examples include tadalafil (Cialis), Stendra (avanafil), and our chewable ED hard mints.

Our guide on how to take sildenafil for erectile dysfunction covers some need-to-know info on Viagra, but it’s no replacement for speaking with a licensed healthcare professional.

If you’re concerned about your sildenafil dosage or are experiencing uncomfortable side effects, you’re wise to see medical advice from a healthcare professional.

If that sounds good, you can start today by booking an online appointment with a healthcare practitioner through our telehealth platform.

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 or medication.

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