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Last updated February 28, 2020. 3 minute read

How does erectile dysfunction (ED) medication work?

ED medications work by blocking PDE5. When that happens, cGMP doesn’t get broken down, and the tissues in the penis stay relaxed and engorged with blood. ED meds are highly effective for erectile dysfunction, but they don’t work all by themselves. You need to feel sexually aroused, as well.

Self Written by Michael Martin
Reviewed by Dr. Mike Bohl, MD, MPH

Getting an erection is a complicated chain of events that involves your brain, heart, lungs, arteries, hormones, and perhaps Netflix. But fundamentally, erections are all about blood flow. ED medication works by interfering with the chemical process that lets blood leave an erect penis.

Vitals

  • ED medications are part of a class of drugs known as PDE5 inhibitors.
  • They work by preventing the chemical process that allows blood to leave an erect penis.
  • ED meds come with the potential for side effects and certain drug interactions.
  • Other treatments for ED include lifestyle changes, non-oral drugs, and natural remedies.

What is erectile dysfunction?

ED is when you can’t get or keep an erection sufficient enough for a satisfying sex life. That might include erections that don’t last as long as you want or aren’t as firm as you’d like. ED is the most common sexual dysfunction: In fact, it’s estimated that more than 30 million American men have experienced ED (Nunes, 2012).

What medications are used to treat ED?

Erectile dysfunction meds are part of a family of drugs called phosphodiesterase type 5 (PDE5) inhibitors (Huang, 2013). They include sildenafil (brand name Viagra), tadalafil (brand name Cialis), vardenafil (brand name Levitra), and avanafil (brand name Stendra).

Sildenafil, the first PDE5 inhibitor, was originally formulated to treat high blood pressure. As it was tested, researchers discovered an unexpected side effect: Men taking the drug were reporting more erections.

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How do ED medications work?

During an erection, a natural chemical called cyclic guanosine monophosphate (cGMP) relaxes smooth muscle in the arteries of the penis. That allows blood to flow into penile tissue, where it’s trapped (Corbin, 2004).

Eventually, an enzyme called phosphodiesterase type 5 (PDE5) “turns off” the erection by breaking down cGMP. This causes the penis to release that trapped blood, and the erection subsides.

ED medications work by blocking PDE5. When that happens, cGMP doesn’t get broken down, and the tissues in the penis stay relaxed and engorged with blood.

ED meds are highly effective for erectile dysfunction, but they don’t work all by themselves. You need to feel sexually aroused, as well.

If you’re experiencing ED, it’s a good idea to talk with a healthcare provider about it. It’s not just your sex life that may be at stake: That’s because, in some men, ED can be the first sign of a serious medical condition such as heart disease, high blood pressure, or diabetes.

Side effects and potential risks of ED medication

Like all drugs, ED medications come with the potential for side effects and drug interactions. 

Common side effects of PDE5 inhibitors include:

  • Flushing
  • Upset stomach or indigestion
  • Headache
  • Sensitivity to light (objects may seem to have a blue tinge )
  • Runny nose or nasal congestion
  • Body aches, including back pain

You should not take oral ED medication if:

  • You’re taking nitrates
  • You’re on dialysis for kidney disease
  • You have severe liver disease

When talking with a healthcare provider about erectile dysfunction medication, be sure to thoroughly describe any medical conditions you have and any current medications you’re taking.

Other treatments for ED

Lifestyle changes

Your cardiovascular system is essential in getting blood where it needs to go throughout the body—including your penis. To keep it healthy, exercise regularly and follow a heart-healthy diet. Avoid tobacco and limit alcohol, both of which can damage blood vessels and nerves that produce a healthy erection.

Non-oral drugs

Other treatment options include non-oral ED medications like alprostadil, which can be injected into the penis or placed into the urethra as a suppository. If low testosterone is the cause of ED, testosterone replacement therapy (TRT) may be used in the form of a patch, gel, or injection.

Medical devices

Penis pumps and cock rings can be helpful for ED. A penis pump draws blood into the penis, producing an erection. A cock ring is placed around the penis (or around the penis and testicles), keeping blood from flowing out of the erect penis. Penis implants—which include a rod, semirigid implant, or one that can be inflated before sex—are also an option.

Natural remedies

Some men have found natural remedies to be effective against ED. Studies have shown that certain supplements (such as DHEA, ginseng, L-arginine, and yohimbe) may be helpful.