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Erectile Dysfunction Pills

Oral Medications Used to Treat Erectile Dysfunction


Updated October 16, 2011

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Erectile dysfunction pills are probably the best known and most widely used of all erectile dysfunction treatments. Known collectively as PDE5 inhibitors, based on the way they function, they go by brand names, such as Viagra, Cialis, and Levitra.

How They Work
Similar to other erectile dysfunction drugs, all three pills work by allowing increased blood flow to the penis. Unlike MUSE or penile injections, in order for oral medications to work, there must be sexual stimulation for an erection to occur. The differences between the three most popular pills -- Viagra, Cialis, and Levitra -- are minor, and mostly have to do with how long the pills take to work, and how long the effect lasts for.

Depending on which medication you are using, you have to take a pill 15 to 30 minutes before it will take effect. While Viagra and Levitra last for a few hours, Cialis can last for up to three days. How often you can use erectile dysfunction pills will depend on which drug you are using and your personal health. This is why it is recommended that you get your first prescription from a doctor who has conducted a complete physical and is familiar with your overall health. In most cases, it isn't recommended that you ever take oral medication for ED more than once a day.

People who use nitrate drugs should not use Viagra, Cialis, or Levitra. If you have cardiac problems, penile abnormalities, multiple myeloma (a form of cancer), leukemia, liver problems (especially severe liver disorders), kidney problems, or are predisposed to prolonged erections for any reason, you may not be able to use these drugs and should talk with your doctor before considering them.

How Effective are Erectile Dysfunction Pills?
When talking about the effectiveness of treatment for erectile dysfunction, we need to specify what effective means. Is the goal just to produce an erection? Is the goal to be able to feel sexual pleasure, or to increase sexual pleasure? Most research only focuses on erections, and the question that is asked (which is a bit problematic) is whether or not the man was able to have an erection that allowed for intercourse.

Using the erection measure of effectiveness, each of the three major oral medications for erectile dysfunction have about the same effectiveness. While numbers vary from study to study, on the high end, each company has research documenting their drug as being effective as much as 80% of the time.

In terms of satisfaction, it's worth noting that for Viagra, only about half the men who get an initial prescription ever get a second one. In a five-year study of men who experienced erectile dysfunction following radical prostatectomy, 52% found that Viagra didn't help at all, 32% said it helped somewhat, and 13% said it helped a lot. Of those men who found Viagra worked for them, 32% said it produced erections firm enough for intercourse.

Side Effects
All medications come with some side effects, and much depends on the individual. If you are experiencing any side effects that your doctor did not mention initially, you should let them know so they can make sure it isn't a warning sign of a more serious interaction.

Common side effects of oral medications for erectile dysfunction include:

  • Facial flushing
  • Headache
  • Upset stomach

Other known side effects include:

  • Visual problems
  • Nausea
  • Dizziness
  • Nasal congestion

With any erectile dysfunction pill, if you experience an erection for longer than four hours, you should go to an emergency room and/or seek immediate medical attention.

Where to Get Erectile Dysfunction Pills
Before using any medication to treat erectile dysfunction, you should see a doctor for a physical exam and speak with them about your options and what treatment would be safest for you. While there are many places where you can buy erectile dysfunction pills online, and some may seem like a significant savings, it's recommended that you only purchase medications from a company you know and trust. Many of the offers for pills online are outright scams, and others may send you medication that is not what they promised.

Before Taking Erectile Dysfunction Pills
If you are experiencing difficulty with erections, the first step should be to speak with a doctor. Erection problems, and particularly erectile dysfunction are known to be an early warning sign for other potentially serious health problems. It may be your body's way of telling you that something else is going on. You should discuss any oral medication for erectile dysfunction (including those labeled as "natural") with a qualified and trusted health care provider before trying it.


Eardley, I., Donatucci, C., Corbin, J., et. al. "Pharmacotherapy for Erectile Dysfunction" Journal of Sexual Medicine Vol. 7 (2010): 524-540.

Giannitsas, K., Konstantinopoulos, A., Patsialas, C., Perimenis, P. “Preference for and Adherence to Oral Phosphodiesterase-5 Inhibitors in the Treatment of Erectile Dysfunction” Patient Preferences and Adherence Vol. 2 (2008): 149–155.

Lilly USA: Cialis Patient Information

Penson, D.F., McLerran D., Feng Z, et. al. "5-Year Urinary and Sexual Outcomes After Radical Prostatectomy: Results From the Prostate Cancer Outcomes Study". Journal of Urology Vol. 173 (2005): 1701–5.

Pfizer: Information About Viagra

Schering-Plough: Levitra Patient Information [PDF]

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