A conversation with one of the pioneers in sildenafil research

Since 1998, Viagra (sildenafil) has been used for treating erectile dysfunction (ED).

It’s available by prescription for males ages 18 years and older. Side effects are not frequent and usually not severe.

But can you take Viagra daily, and what’s the benefit?

We spoke with Dr. Irwin Goldstein, a primary researcher on the landmark study of oral sildenafil in the 1990s, to answer this and other questions.

The short answer is yes; you can take Viagra or its generic form, sildenafil, every day. Whether you need to or should, depends.

Since each person is different, you should consult with a doctor about what’s best for you.

They can discuss dosage and frequency. They’ll consider your overall health and any other medical conditions you are being treated for.

Viagra may not be safe for you if you have high blood pressure, kidney problems, or a heart condition, for example. It also may interact negatively with some other medications.

Viagra should only be taken once a day.

Goldstein, director of San Diego Sexual Medicine at Alvarado Hospital and clinical professor of surgery at the University of California San Diego, explained to Healthline why blood flow to the penis is important.

“The penis is a unique organ. Arterial blood goes through other organs all the time, but the penis doesn’t have that.

During the day, there’s very little blood flow in the penis. Only during erections is there blood flow. All the other organs are getting the 100 mm of oxygen all day and night, but the penis doesn’t.”

“The penis only gets arterial blood flow during erections and during sleep. A routine night situation would involve 3 or maybe 4 or 5 hours of erection time, depending on how many hours the person slept. So from the perspective of the penis, sleep is the real time when oxygenation occurs.”

For people with ED, a daily dose of Viagra can improve oxygenation for the penis by improving the quality of nighttime erections.

Goldstein noted that having good nighttime erections can help “prevent the scarring of the penis” that normally occurs with age. Controlled studies have shown this going back to 2000.

Ultrasound gives us the ability to assess the degree of scarring in an individual, Goldstein said.

“Taking a PDE5 inhibitor every night can magnify the night erections and increase the chance of oxygenation, which increases the chance of getting rid of that scar tissue.”

How does Viagra work?

Viagra and Cialis (tadalafil) are both phosphodiesterase type 5 (PDE5) inhibitors.

This class of drugs works to relax the smooth muscle in the blood vessels of your penis, which increases blood flow and helps you have and keep an erection.

Healthline

Goldstein discussed the benefits of a daily dose of Viagra.

Some benefits include:

Reduces progression of erectile dysfunction

Taking Viagra daily in a small dose is a way to “reduce the intensity of progression of ED,” according to Goldstein. It’s a “prophylactic.”

Improves ability to urinate

“Daily use of Viagra improves people’s ability to urinate,” Goldstein said.

“As men get older, they have a little bit more difficulty urinating because the prostate gets bigger. The prostate, like the penis, consists of a lot of smooth muscle in it, and relaxing the smooth muscle will lessen the grip of the prostate on the urethra. The higher grip is what causes difficulty in urinating.”

Improves quality of life

“Self-esteem, self-confidence, and self-worth in the male are highly related to sexual function,” Goldstein said.

“And there are multiple reports on men taking PDE5 inhibitors and exhibiting better life quality from the perspective of confidence and satisfaction.”

Endothelial friendly

“PDE5 inhibitors are endothelial friendly medications,” Goldstein said. The endotheleum is the lining of the blood vessel. When it gets injured, this leads to the development of plaque or artherosclerosis.”

For this reason, Goldstein said “one can argue that taking a PDE5 inhibitor daily has led to “fewer strokes, fewer heart attacks, and better erections.”

He noted that the Food and Drug Administration (FDA) had approved a daily dose of Cialis (tadalafil), another PDE5 inhibitor for ED and other uses, in January 2008.

Viagra comes as an oral tablet in different dosages. Discuss with your doctor what’s an appropriate dose for you.

For daily use, Goldstein said, the generic form, sildenafil, comes in 20-mg tablets.

“We prescribe one 20-mg tablet a night, a classic dose,” he said. “Should they wish to have sex, they bump up the dose to four more tablets to get to the 100-mg maximum dose.

When used to get an erection, Viagra generally takes about half an hour to an hour to work. Exactly how soon it works varies individually. But in all cases, you’ll need to be sexually aroused to get an erection.

Prescriptions for daily use of Viagra are now relatively common, Goldstein said, especially since the FDA approval of daily Cialis.

Side effects from Viagra are usually mild and may go away in time. Side effects include:

  • headache
  • stomach upset
  • stuffy nose
  • back pain
  • nausea
  • muscle pain
  • dizziness
  • rash
  • vision problems

Goldstein noted that there were very few side effects with a 20-mg daily dose.

Viagra was the first ED medication, but now there are several drugs to use for ED. So if Viagra doesn’t work well for you, discuss other options with your doctor.

Each of these drugs is slightly different in composition from Viagra, and you may react differently to them. The dosage may also be different.

Tadalafil, for example, starts at a smaller dose and is active in your system for a longer time.

Other drugs include:

Taking a daily dose of Viagra can help stop the intensity of the progression of ED.

It also has other benefits, including improving your ability to urinate and improving your quality of life in general.

Discuss dosage and frequency with your doctor to determine what works best for you.


Marjorie Hecht is a longtime magazine editor and writer, now working as a freelancer on Cape Cod. Her specialties are science, technology, and medicine, but her eclectic career includes being a reporter at the United Nations and covering politics in Washington, D.C. She has an MSW from Columbia University, a BA from Smith College, and she did postgraduate work in race and demography at the London School of Economics.