Study shows risk of erectile dysfunction (ED) is not increased for users of finasteride

By Sara Wasserbauer, MD

Internet hype regarding medical issues that are emotionally charged (like autism and vaccines, etc.) should always be met with a healthy dose of skepticism.  Hair loss is one of these medical issues.  Decades of scientific research and reams of data seem to show this drug is both safe and effective.  And yet the Internet portrays a different view that is very convincing and concerning!  Which characterization should you believe?

I like hair.  So, as a physician specializing in hair loss and its treatment, I have an inherent bias toward any treatment that will grow hair.  My first duty though, is to provide treatments that will not harm my patients – so when anything new comes out about the safety of hair loss medications like finasteride my information appetite is voracious.

Enter the newest study on the effects of 5 alpha reductase inhibitors (also known as 5ARIs) like finasteride and dutasteride on erectile dysfunction (ED).  This study had a large number of patients and was conducted over an average of 4 years.  It was funded by the US National Institutes of Health and the National Institute of Diabetes and Digestive and Kidney Diseases. The authors disclosed no current financial conflicts.

The study showed that the risk of erectile dysfunction (ED) is not increased for users of finasteride when compared with other men who also have hair loss (aka alopecia).

The limitation of this study is that it relied on data of written prescriptions – not dispensed medications.  That means any one patient may not have actually filled a prescription, or even taken the drug!  However, that is unlikely with 71,849 patients, so it is hard to dispute this data.

So the facts as they stand are this:

  • 5ARI therapy does not increase the risk of incident ED, regardless of indication for use
  • the longer you have BPH, the higher your risk of erectile dysfunction (ED)
  • risk factors known to be independently associated with risk for ED are increased body mass index (BMI), depression, hypertension, hyperlipidemia, smoking, and diabetes

Medications for hair loss are not indicated for everyone.  Each patient is different, and for some patients, finasteride is simply not their first choice or their only option.  But for those who interested in using drugs like finasteride to keep their hair, this study should provide a welcome sigh of relief.