Erectile dysfunction pills and medications: Viagra, Cialis, and more

Reviewed by Chimene Richa, MD, 

Written by Health Guide Team 

Reviewed by Chimene Richa, MD, 

Written by Health Guide Team 

last updated: Sep 15, 2022

4 min read

If you think getting an erection is nothing more than the result of an erotic internet search or two, think again. Getting and maintaining an erection is a complicated chain of events that involves hormones, chemicals, multiple systems in the body, and arousal. Erectile dysfunction (ED) pills work by increasing blood flow to the penis, allowing it to get and stay erect longer. 

Read on to learn all about erectile dysfunction pills, how they work, risks, benefits, and other potential treatments for ED. 

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What is ED?

Erectile dysfunction, or ED, is when you struggle to get or keep an erection sufficient 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.

There are many potential causes of erectile dysfunction. Because healthy blood flow is required to get and maintain an erection, ED may be caused by health conditions that impact blood flow, including (Sooriyamoorthi, 2022): 

Certain medications like antidepressants (SSRIs), hair loss drugs, high blood pressure medications (beta-blockers), and more may cause erectile dysfunction (Sooriyamoorthi, 2022).

People with ED often feel embarrassed by the condition, but it's one of the most commonly experienced sexual disorders. An estimated 52% of American men between the ages of 40 and 70 deal with ED, although it’s difficult to know the exact numbers (many people are reluctant to talk about ED) (Sooriyamoorthy, 2022).

If you experience ED, it's a good idea to seek medical advice from a healthcare provider. That’s because it's not just your sex life that may be at stake—in some people, ED can be the first sign of one of the serious underlying conditions just mentioned.

What are ED pills?

ED pills are part of a family of drugs called phosphodiesterase type 5 (PDE-5) inhibitors. Currently, PDE-5 inhibitors approved by the US Food and Drug Administration (FDA) include (Dhaliwal, 2022):

The first PDE-5 inhibitor, sildenafil, was originally formulated as a prescription drug to treat high blood pressure. As researchers tested it, they discovered an unexpected side effect: men taking the drug reported more erections (Goldstein, 2019).  

Viagra Important Safety Information: Read more about serious warnings and safety info.

Cialis Important Safety Information: Read more about serious warnings and safety info.

How do ED pills work?

An erection begins with stimulation, which can be sensory (like touch, smell, and sight) or psychological (thinking of something that turns you on).

During sexual arousal, nerves tell the penis, “it’s time to get hard!” and stimulation begins. This triggers the production of cyclic guanosine monophosphate (cGMP), which relaxes smooth muscles in the penis’s arteries and allows a rush of blood to flow into the penis, creating an erection (Dhaliwal, 2022). 

After ejaculation, PDE-5 (the enzyme we mentioned earlier) "turns off" the erection by breaking down cGMP. Once cGMP is broken down, the penis releases any trapped blood, and the erection subsides. 

Erectile dysfunction pills work by blocking PDE-5 (hence the name, PDE-5 inhibitors) and preventing cGMP from breaking down. The result is an engorged penis that remains erect longer (Dhaliwal, 2022). 

PDE-5 inhibitors are highly effective at treating ED, but you need to be sexually stimulated for the pills to work


How effective are ED pills?

Research shows that, when used properly, ED pills can help improve erectile function.

An extensive analysis of clinical data found that participants who took either sildenafil, tadalafil, or vardenafil (avanafil wasn’t available at the time of this study) experienced better erections. In fact, around 70% of people had improved erections or more successful sex after using one of these three pills. The analysis did not find significant differences in effectiveness or side effects between the medications studied (Tsertsvadze, 2009). 

How to use ED pills

As mentioned, ED pills can help make erections firmer and last longer, but they won’t give you an erection without some sort of sexual stimulation. 

The duration of the effects depends on which ED pill you take. Sildenafil lasts about 4–5 hours, avanafil lasts 6 hours, and vardenafil works for up to 8 hours. Tadalafil, the longest-lasting pill of all PDE-5 inhibitors, lasts up to 36 hours (Khera, 2022). 

Potential risks and side effects of ED medication

ED medications come with the potential for side effects and drug interactions. Common side effects of PDE-5 inhibitors include (Dhaliwal, 2022):

  • Flushing (experienced more with sildenafil)

  • Upset stomach or indigestion

  • Headache

  • Dizziness

  • Changes in vision (objects may seem to have a blue tinge)

  • Runny nose or nasal congestion

  • Body aches and back pain

  • Low blood pressure

Rare side effects of ED pills include (Dhaliwal, 2022):

  • A stroke to the optic nerve, also called nonarteritic ischemic optic neuropathy

  • Hearing loss

  • Priapism (an erection lasting 4 hours or longer)

You should not take oral ED medication if you’re also taking nitrates or nitroglycerin, a drug used to treat episodes of chest pain in people with heart disease. Mixing the two medications can lead to a severe drop in blood pressure (FDA, 2011). 

Be careful using ED pills if you have any of the following health conditions (Dhaliwal, 2022):

  • A recent history (six months or less) of heart attack or stroke

  • Serious problems with heart rhythm

  • High or low blood pressure

  • History of heart failure or chest pain

When talking with a healthcare provider about ED pills, be sure to discuss any medical conditions you have as well as the medications you take. Some drugs, like alpha blockers, may increase the risk of side effects. 

How much do ED medications cost?

Many insurance providers cover erectile dysfunction pills. However, check with your insurance provider to find out if they will cover your pills. 

Some providers may only cover a particular medication, not all PDE-5 inhibitors. If you have to pay out of pocket, the cost may vary significantly depending on whether you buy brand name or generic ED pills. In general, generic drugs tend to be cheaper than their brand-name counterparts. 

Sildenafil and tadalafil are typically less expensive than the newer vardenafil. Avanafil is the latest addition to the PDE-5 inhibitor family and is not available as a generic drug. It’s currently the most expensive of the ED medication options.

In recent years, ED medications have become widely available online (with a prescription) for safe and discreet delivery. If you struggle with erectile dysfunction, speak with your healthcare provider. They will help you find a treatment for erectile dysfunction that works for you.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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  • U.S. Food and Drug Administration (FDA): Cialis (tadalafil) tablets label. (2011). Retrieved on Sep. 12, 2022 from

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

September 15, 2022

Written by

Health Guide Team

Fact checked by

Chimene Richa, MD

About the medical reviewer

Dr. Richa is a board-certified Ophthalmologist and medical writer for Ro.