National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Adverse events of 5-alpha-reductase inhibitors


Other Names:
Post Finasteride syndrome
This page does not serve as an official recognition of post-finasteride syndrome by the NIH. Please see our Disclaimer for more details. This page was created to provide a list of resources where you can find more information about reported adverse events of 5-alpha reductase inhibitors, which is sometimes referred to as post-finasteride syndrome. Some patients who have taken finasteride have referred to side effects such as sexual dysfunction and depression (sometimes severe). Limited information is available for patients and healthcare professionals on these side effects and whether or not they are permanent. Studies are underway to better understand the effects of 5-alpha reductase inhibitor drugs. We intend this page to be a place where you can find reliable information, and we will update the page as new information becomes available.
Last updated: 3/3/2015
Please talk to your doctor about the specific symptoms you're experiencing. If you're currently taking a 5-alpha-reductase inhibitor drug, discuss your concerns about the medication. Ask your doctor about other treatment options for managing your condition. 

Also, we recommend that you submit your symptoms to your nation's drug regulatory agency. In the United States, it is the FDA.  Reporting of adverse events and medication errors is voluntary. The MedWatch site provides information about voluntary reporting. 

People outside the US can find a list of international reporting agencies at the following link to the World Health Organization's Uppsala Monitoring Centre: 
https://www.who-umc.org/global-pharmacovigilance/who-programme-for-international-drug-monitoring/

Currently, there is very limited information in the medical literature to guide treatment of symptoms that may occur in association with 5-alpha-reductase inhibitor use. There is little data to help a person anticipate what may be in the future in regards to their symptoms. Discuss the possible risks and benefits of your treatment given possible side effects. If you experience what you see as side effects, talk to your primary care provider about appropriate referrals to specialists, such as endocrinologists, urologists, or psychologists who may be able to address your individual symptoms. 

The NIH funded 2 research studies to learn more about the relationship between 5-alpha-reductase inhibitors and erectile dysfunction, other sexual dysfunction (ejaculatory and psychosexual dysfunction, low libido, Peyronie's disease), breast outcomes, and depression. Researchers also investigated the persistence of symptoms and risk factors for such persistence. Click on the study title below to visit the NIH RePORTer and read more about these study summary. The RePORTer is a NIH tool that has information on all NIH-funded research activities. 

AN EPIDEMIOLOGIC EVALUATION OF ADVERSE EVENTS OF 5-ALPHA-REDUCTASE INHIBITORS 

Patient advocacy groups are another source for learning more about clinical research opportunities. You can check the Post-Finasteride Syndrome Foundation Web site for information on PFS Research Initiatives.

While we are not aware of a clinical research study enrolling people with adverse events from taking 5 alpha-reductase inhibitors at this time, you can periodically check the Research section of this Web page for updates.  You can also consider joining a patient research registry. Patient registries collect and organize health information. They help researchers design new studies and find people who might want to participate.

ResearchMatch is a free national research registry designed to bring together patients, healthy volunteers and researchers. ResearchMatch was developed by major academic institutions across the country and is funded by the National Center for Advancing Translational Sciences, NIH.
Last updated: 2/8/2016

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The Post-Finasteride Syndrome Foundation provides information on research initiatives through their Web site. Click on Post-Finasteride Syndrome Foundation to view this information.
  • The Research Portfolio Online Reporting Tool (RePORT) provides access to reports, data, and analyses of research activities at the National Institutes of Health (NIH), including information on NIH expenditures and the results of NIH-supported research. There is a study titled AN EPIDEMIOLOGIC EVALUATION OF ADVERSE EVENTS OF 5-ALPHA-REDUCTASE INHIBITORS that may be of interest to you. Click on the study title to learn more.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • PubMed is a searchable database of medical literature and lists journal articles that discuss Adverse events of 5-alpha-reductase inhibitors. Click on the link to view a sample search on this topic.

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  • I think I suffer from this disease, what should i do? See answer