Post-Finasteride Syndrome (PFS) describes persistent sexual, neurological, and physical adverse reactions in patients who have taken finasteride, a 5-alpha reductase type II enzyme inhibitor used to treat hair loss (under the brand name Propecia or generics) or enlarged prostate (Proscar or generics).

Unfortunately, PFS is a condition with no known cure and few, if any, effective treatments. As an increasing number of men report their persistent side effects to health and regulatory agencies worldwide, medical and scientific communities are only beginning to realize the scope of the problem.




FDA-Mandated Labeling Changes for Finasteride

  • A revision to the Propecia label to include libido disorders, ejaculation disorders, and orgasm disorders that continued after discontinuation of the drug.
  • A revision to the Proscar label to include decreased libido that continued after discontinuation of the drug.
  • A revision to both the Propecia and Proscar labels to include a description of reports of male infertility and/or poor semen quality that normalized or improved after drug discontinuation.”

— Source: FDA (April 2012)


Our research definitely concludes that PFS is real.

For a subset of these men, the damage persists—maybe forever—even after they go off the drug.

We don’t fully understand why, but it is as if something shuts off biologically, and stays that way.

— Dr. Abdulmaged M. Traish, PhD, Professor of Biochemistry at Boston University School of Medicine: Men’s Health (November 2011)


I have recently seen an increasing number of men who have developed significant degrees of clinical hypogonadism – low sex drive, erectile dysfunction, reduced sexual sensations and listlessness, fatigue and/or ‘brain fog’ – while either taking finasteride or after stopping the medication, even long after stopping it.

… If high normal levels of testosterone, combined with low estrogen levels, does not relieve the hypogonadal symptoms, then the possibility that the man has some resistance to testosterone must be considered.”

—  Dr. Alan Jacobs, Neuroendocrinologist: A Neuroendocrine Approach To Finasteride Side Effects In Men (April 2010)


Hardly a week goes by that I am not being approached by yet another young man recently prescribed Propecia as a “treatment” for male pattern baldness.

This drug has the capacity to obliterate their sexuality, not just for the time that they take the drug, but for all time.

This vanity treatment can and does condemn many young men to a life sentence of sexual anhedonia, without feeling, desire or function, to otter misery and despair for which, as yet, we have no treatment.”

—  Dr. Andrew Rynne, Irish Medical Council: Benign Prostatic Hyperplasia (March 2011)


We are becoming more and more aware of persistent sexual health problems occurring as a result of the use of 5 alpha reductase inhibitors, finasteride, and dutasteride, in a subset of patients.

What is even more alarming is that in addition to persistent sexual issues, there are persistent central cognitive issues and concerns of persistent depression.”

— Dr. Irwin Goldstein, Editor-in-Chief, Journal of Sexual Medicine: An Old Problem with a New Cause—5-Alpha Reductase Inhibitors and Persistent Sexual Dysfunction (July 2011)


It’s been very frustrating for a lot of these men because they’ve sought care from medical professionals who are unaware of the risk of persistent and serious sexual dysfunction since it was not originally suggested in the literature.

… Finasteride is different because it can actually change the brain’s chemistry. The enzyme 5-alpha reductase is present in many areas of the brain.

It is rare for a drug to have the capability to persistently change the brain’s chemistry.”

—  Dr. Michael Irwig, F.A.C.E., Assistant Professor of Medicine, George Washington University School of Medicine: Doctors link hair growth drug to sexual dysfunction, depression and cancer (Feburary 2012)


Several young men seen for hypogonadism (low libido, erectile dysfunction, low energy, etc) after using finasteride have been found to have low-normal levels of bio-available testosterone and LH.

This leads to the question of whether partial androgen resistance is at play.”

—  Dr. Alan Jacobs, Neuroendocrinologist: A Proposed Mechanism For Prolonged Sexual Side Effects From Finasteride (June 2010)