What Are ED Medications And How Do They Work?

By The Rex MD Editorial Team

August 27, 2020

Reviewed by
Jeff Toll, MD

Medications for erectile dysfunction are designed to help men get and maintain an erection. They're incredibly effective, and the most popular ED meds have been used for more than 20 years by millions of men globally.

ED meds exploded onto the scene in the 90's to tremendous fanfare and rapid traction with the 40% of men affected by ED before the age of 60. Viagra (sildenafil) was the first, approved by the U.S. FDA on March 27, 1998. Originally synthesized to be tested as a treatment for high blood pressure, researchers quickly realized it had some unexpected "side effects" within 30-60 minutes of taking the drug. 

The company behind this new discovery, Pfizer, fast-tracked its development, and so began the massive success of this ubiquitous little blue pill. In its first year on the market, Pfizer booked nearly $1 billion in sales from Viagra as it was touted in direct to consumer advertising by well-known men at the time, including Bob Dole and Brazilian soccer legend Pele. With Viagra's success, Cialis (tadalafil) and Levitra (vardenafil) from Eli Lilly and GlaxoSmithKline were hot on its heels. 

Over 20 years later, all three medications – which work by the same mechanism of action – are available as generic ED meds and have been used successfully and safely by tens of millions of men to get stronger erections.

ED is no longer the taboo it once was.

How do ED meds work?

The most popular ED meds Viagra (sildenafil), Cialis (tadalafil), and Levitra (vardenafil) all work by the same pathway in the human body: they are all PDE5 (Phosphodiesterase 5) inhibitors.

In the penis, nitric oxide (NO) plays a major role in causing erections during sexual stimulation. It essentially helps to create cGMP (cyclic guanosine monophosphate), which is one of the primary molecules that causes vasodilation (wider blood vessels) and more blood flow to the penis tissue. Increased blood glow causes an erection.

cGMP normally gets broken down in the body (and penis) by the enzyme PDE5. By inhibiting PDE 5, sildenafil and its sister molecules allow cGMP to do its work faster and longer. They basically release the brakes on an erection. 

What's neat about most of these drugs is they work well for a few hours, but for most men they do require some sexual stimulation before they cause an erection. In other words, if there's a "missed opportunity" it's not that big of a deal. And, when you take a PDE5 inhibitor, you've loaded your gun for the next hour or three. 

How do I take ED meds?

Most of these medications are taken by mouth 30 minutes to a few hours before sexual intimacy. Cialis is also available in a lower dose (Cialis daily) that you can take once daily to be ready for anything. Tabs that dissolve under your tongue are also available for some of these medications.

Doses can vary, but 50mg Viagra tablets are the most popular and most-often prescribed. It's also available in 25 and 100mg tablets, and generic sildenafil comes in a variety of doses as well.

ED meds can be taken as needed, but all of these popular products include instructions in their FDA approved labels not to take them more than once daily. 

Want to learn more? Rex MD is here to help men access the most popular and effective ED medications at great prices and with the simplicity of ordering online. Our telemedicine platform lets you connect with a Rex MD physician to prescribe your medication, and we then ship your medication to your home with 2-day free shipping. It's fast, convenient, and discreet... and it's helping millions of men nationwide. 

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Disclaimer : This article is for information only and should not be considered medical advice. Always speak with your doctor about your health and the benefits or risks of any treatment or intervention. This information should not be relied on as a substitute for professional medical advice.