The Post-Finasteride Syndrome Foundation is dedicated to funding research on the characterization, underlying biologic mechanisms and treatments of post-finasteride syndrome (PFS). A secondary goal is to increase global public awareness of PFS.

Often life-altering, PFS is characterized by devastating sexual, neurological, and physical side effects that persist in men who have taken the 5-alpha reductase type II enzyme inhibitor finasteride.

Finasteride is prescribed for the treatment of hair loss under the brand name Propecia (and generics) and for the treatment of enlarged prostate under the brand name Proscar (and generics).



Post Finasteride Syndrome

The most common persistent side effects of finasteride are loss of libido, erectile dysfunction, depression, suicidal ideation, anxiety, panic attacks, Peyronie’s disease, penile shrinkage, gynecomastia, muscle atrophy, cognitive impairment, insomnia, severely dry skin and tinnitus. These can last for years after stopping the drug. [more…]



The PFS Foundation’s primary objective is to help establish medical consensus and acceptance of PFS by promoting scientific and clinical research. Research initiatives focus on uncovering underlying biologic mechanisms for the syndrome and its persistent side effects at a molecular level. [more…]



The PFS Foundation serves as a central resource for published research on the condition, including recent studies in JAMA Dermatology, The Journal of Clinical Endocrinology & Metabolism, and Pharmacotherapy. We facilitate collaborative efforts amongst health care professionals and leading scientists worldwide.  [more…]

Medical Awareness



Symptomatic finasteride users had “significantly lower International Index of Erectile Function composite score” and “significantly lower scores for each of its domains of erectile function, sexual desire, orgasmic function, intercourse satisfaction, and overall satisfaction”… There exists “a significant positive correlation between a subset of Beck Depression Inventory scores related to negative attitude and blood oxygen level dependent activity.”

Characteristics of Men Who Report Persistent Sexual Symptoms after Finasteride Use for Hair Loss: Shalendar Bhasin, MD, The Journal of Clinical Endocrinology & Metabolism, September 2016



Our chief objective was to assess whether longer duration of 5α-RI exposure increases risk of [persistent erectile dysfunction]… Among men with 5α-RI exposure, 167 of 11,909 (1.4%) developed PED… Of 530 men with new ED, 167 (31.5%) had new PED. Men without prostate disease who combined NSAID use with >208.5 days of 5α-RI exposure had 4.8-fold higher risk of PED than men with shorter exposure… Conclusion and relevance: Risk of PED was higher in men with longer exposure to 5α-RIs. Among young men, longer exposure to finasteride posed a greater risk of PED than all other assessed risk factors.

Persistent erectile dysfunction in men exposed to the 5α-reductase inhibitors, finasteride, or dutasteride: Steven M. Belknap​​, MD, PeerJ, March 2017


A review of 17 randomized controlled trials (including more than 17,000 patients) demonstrated a nearly twofold increase in sexual, ejaculatory and orgasmic dysfunction in young men using Propecia for male pattern hair loss. At the same time, a recent study demonstrated changes in the levels of certain steroids in cerebrospinal fluid of men taking finasteride for hair loss. These steroids have been shown to influence brain function, and their presence may help explain the profound psychological changes such as depression and suicidality that have been associated with finasteride use. This research should cause us to think more carefully about this commonly encountered medication.

— Daniel Marchalik, MD, Urologist at MedStar Washington Hospital Center


A group of Italian researchers gave finasteride to rats and noticed that the number of androgen receptors in their brains went up. Moreover, the effects persisted long after the drug had been discontinued… [T]hey then called in men with PFS, took skin from the penis and found that the density of androgen receptors in men with PFS was about twice that of those without. Now, remember the idea of the testosterone bell curve and damping effects (little testosterone, little growth, more testosterone, more growth, even more testosterone, reduced growth)? I think this is what we are seeing here. With a greater concentration of receptors, the organ becomes more sensitive to testosterone and at a certain point, paradoxically, that sensitivity may shut down.

— Charles J. Ryan, M.D., Distinguished Professor of Clinical Medicine and Urology at the University of California, San Francisco


Using finasteride for hair loss is like shooting at sparrows with cannons. The drug…blocks not only the super hormone but also other hormones that affect thinking and psyche, mood and emotions. Discontinuation of the drug should actually make the hormones work again…but apparently, something breaks down in some men, in the prostate, in the brain, in the whole organism.

— Michael Zitzmann, MD, andrology professor at the University of Munster, Germany


We are certainly very cautious, because we see the side effects. We wouldn’t recommend that any man take [finasteride], especially not young men. The longer they take it, the greater the risk of experiencing persistent side effects, including after they’ve stopped.

— Doris Mannhard, M.D., Urology Clinic, University Hospital Zurich



Gynecomastia in men taking this drug is proven. I will not be against the prohibition of Propecia. If it were me, I wouldn’t take it.

François Desgrandchamps, M.D., Ph.D., Chief of Urology at St. Louis Hospital, Paris, France



Long-term adverse symptoms of men who used oral finasteride against androgenic alopecia have been recently described as post-finasteride syndrome. Aim: To determine whether (CAG)n-rs4045402 and (GGN)n-rs3138869 polymorphisms in the androgen receptor (AR) gene are implicated in PFS. Conclusion: This study showed that short and/or long (CAG)n and (GGN)n repeats had different frequencies according to symptoms reported by patients with PFS.

Androgen Receptor (AR) Gene (CAG)n and (GGN)n Length Polymorphisms and Symptoms in Young Males With Long-Lasting Adverse Effects After Finasteride Use Against Androgenic Alopecia: Sabrina Cauci, The Journal of Sexual Medicine, November 2016


Sexual dysfunction and suicidal ideation that appears to result from [finasteride] are important adverse effects. Patients should be informed of these risks, so that they can weigh the benefits of harms against treatment.

— Finasteride 1 mg in Alopecia: Sexual Dysfunction, Suicidal Ideation: Bruno Toussaint, MD, managing editor, Prescrire, October 2016


[O]ur results showed that [finasteride] treatment affected the expression of a number of accumbal proteins involved in key functional processes, such as regulation of GABAergic neurotransmission, as well as steroid and pyrimidine metabolism. These findings may prove crucial to understanding the neurochemical mechanisms of FIN’s neuropsychiatric side effects.

Exploring the Neural Mechanisms of Finasteride: A Proteomic Analysisin the Nucleus Accumbens: Alessio Soggiu, PhD, Psychoneuroendocrinology, October 2016


The proportion of men taking 5ARIs and experiencing erectile dysfunction is likely around 5 percent. I think it’s important to be educated about the potential side effects.

Landon W. Trost, MD, head of andrology, the Mayo Clinic



A.M. Traish

Our findings suggest that finasteride therapy is associated with undesirable and, in some cases, detrimental sexual side effects and reduced quality of life… The argument that the benefits of [finasteride] outweigh the risks is slowly eroding in the face of new emerging scientific evidence from preclinical and clinical studies. The available data demonstrate that such drugs do pose serious adverse effects, especially in a subset of men who may have the predisposition to be affected severely… Physicians need to be aware of the adverse side effects of these drugs and are encouraged to share this information with their patients prior to commencing therapy with finasteride.

Abdulmaged M. Traish, PhD, Prof. of Biochemistry and Urology, Boston University School of Medicine



My yardstick for treating any patient is, what would I do if this were my own son? Ten years ago, I would have answered differently. But now I would not feel comfortable recommending Propecia to a young, sexually active man.

Nelson Novick, MD, Clinical Professor of Dermatology, Mount Sinai School of Medicine, New York



The levels of some neuroactive steroids analysed in CSF of PFS patients were significantly different versus those in healthy controls. In particular, the levels of PREG, as well as of its further metabolites, PROG and DHP, were significantly decreased in CSF of PFS patients… PFS patients show altered levels of important physiological regulators of brain function, such as neuroactive steroids. This could explain the andrological and psychiatric features observed in PFS patients.

— Roberto Melcangi, PhD, Professor of Endocrinology, University of Milano


Jan Tytgat. MD

I don’t think it’s very responsible for dermatologists to use [finasteride] to combat hair loss.  You must know that this molecule, finasteride, has been the subject of more than 2,600 scientific articles found in trustworthy databases.  And they all say, You may be able to reduce baldness, but it comes with a serious risk of impotence, ejaculation problems, testicular pain and, just as bad, a risk of breast cancer.

— Jan Tytgat, PhD, Professor of Toxicology and Pharmacology, KU Leuven University.



Concern regarding adverse effects of finasteride is increasing. We aimed to determine the type and frequency of symptoms in men having long-term sexual and non-sexual side effects after finasteride treatment… The most frequent sexual symptoms…were loss of penis sensitivity (87.3%), decreased ejaculatory force (82.3%), and low penile temperature (78.5%). The most frequent non-sexual symptoms were reduced feeling of life pleasure or emotions (75.9%); lack of mental concentration (72.2%), and loss of muscle tone/mass (51.9%)…Further studies are necessary to investigate the pathophysiological and biochemical pathways leading to the post-finasteride syndrome.

— Carlo Trombetta, MD, Urological Hospital, Department of Medical, Surgical and Health Sciences, University of Trieste



[Finasteride therapy] is a modification of the hormonal mechanism, which raises the question of reversibility. Does stopping treatment mean the physiological mechanism of testosterone secretion is reset? I can’t answer. We probably don’t have the precise data we’d need to answer that.

— François Haab, MD, Chairman, Urology Department, Tenon Hospital, Paris


Dirk Michielsen. MD

It’s awful when a patient doesn’t know what’s happening, and takes a medication for a specific purpose, but then develops side effects that may be more damaging than its positive effects. The patient needs to know that, and to be able to say, I’m stopping now. That’s the responsibility of the doctor who prescribes the medication, or the pharmacist who supplies it.

— Dirk Michielsen, MD, Professor of Urology, Ziekenhuis University


Christine A Ganzer

In this pilot study, we sought to characterize sexual and nonsexual adverse effects that men reported experiencing at least 3 months after stopping the medication… Responses from 131 generally healthy men (mean age, 24 years) who had taken finasteride for male pattern hair loss was included in the analysis. The most notable finding was that adverse effects persisted in each of the domains, indicating the possible presence of a “post-finasteride syndrome.

Christine A Ganzer, PhD, Assistant Professor, City University of New York


To date there are no predictive factors for the risk of development of post-finasteride syndrome and no known treatment for the disorder. For the time being, as a general rule: Refrain from prescribing oral finasteride to a patient with a personal history of depression, sexual dysfunction, or fertility problems.

Ralph M Trüeb, MD, Center for Dermatology and Hair Diseases, Zürich, Switzerland


The effects in the brain of finasteride…have been poorly explored. Therefore, the effects of a subchronic treatment of finasteride…and the consequences of its withdrawal on neuroactive steroid levels…have been evaluated in male rats…One month after the last treatment… changes in neuroactive steroid levels, steroid receptors…and GABA-A receptor subunits…were detected. These findings suggest that finasteride treatment may have broad consequences for brain function.

Silvia Giatti, PhD, Department of Biomolecular Pharmacology, The University of Milan


We advise against the use of cosmetic treatments that have a significant potential for endocrinological side effects. Propecia should not have been authorized in the first place, and its approval should be revoked as soon as possible.

Dietrich von Herrath, MD, head physician, St. Joseph Hospital, Berlin, and co-editor, Der Arzneimittelbrief (The Drug Letter)




Post-finasteride syndrome is now a recognized condition, affecting as many as 20 per cent of those taking finasteride… The persistent sexual side-effects of finasteride may manifest after varying periods of taking the drug, or not until the drug is discontinued. It is not known why some men are susceptible to the potential adverse effects of finasteride, while others—the majority—are not affected… Further research is needed on who is susceptible to the persistent, adverse side-effects of finasteride and on the underlying mechanisms of the medication.

Andrew Rynne, MD, Clane General Hospital, Kildare, Ireland



Treatment of young subjects is of increasing concern due to accumulating evidence that daily use of oral finasteride has several severe adverse effects… Since finasteride inhibits T conversion into DHT, which is responsible for most androgen activity, it is plausible that prolonged finasteride use in predisposed individuals could simulate the effects of aging in young men. Since some of the effects of androgen inhibition cannot be reversed once local androgen levels are re-established, it is temping to speculate that patients could still suffer from adverse sexual effects several months or even permanently after finasteride discontinuation.

Carla Di Loreto, PhD, Department of Medical and Biological Sciences, School of Medicine, University of Udine, Udine, Italy


Persistent adverse effects of finasteride in younger men include erectile dysfunction, low libido, lack of orgasms, depression, and decreased alcohol consumption. One study has found lower levels of several neurosteroids in this population. Out of the various persistent side effects, erectile dysfunction and decreased alcohol consumption have been the most studied in animal models. Further research is needed on who is susceptible to the persistent adverse side effects of finasteride and on the underlying mechanisms of the medication.

Michael S. Irwig, MD, Associate Professor of Medicine, Director of Andrology, George Washington University






Persistent adverse effects development from finasteride in young men include erectile dysfunction, low libido, lack of orgasm and depression. Finasteride use in young males is a potential risk for their sexual health, Physicians treating male pattern hair loss should discuss with patients the potential risk of PAEsD with finasteride. We propose that the Dermatologist Society remove from their guidelines “the utilization of finasteride for MPHL.”

Kim M. Drasa, MD, Professor of Urology, University of Medicine, Head of Department of Urology & Sexology, Central Polyclinic, and President Albanian Urologists & Sexologists Association


Donatella Caruso

Observations performed in a subset of patients treated for male pattern hair loss indicate that persistent sexual side effects as well as anxious/depressive symptomatology have been reported even after discontinuation of finasteride treatment.

Donatella Caruso, PhD, Associate Professor, Department of Pharmacology and Biomolecular Sciences, University of Milan



Post-finasteride syndrome is a serious state of permanent sexual, mental and physical side effects which do not resolve after quitting the drug… It is also surmised by the few specialists in the medical field that a type of receptor or “brain damage” has occurred… Men suffering from PFS are plagued with many physical, mental, and emotional symptoms that have led to long-term depression, marital problems and divorce, and now several reported cases of suicide.

Matthew Bruhin, PhD, psychotherapist, San Diego, Calif.


Finasteride is a steroid 5-alpha-reductase inhibitor, approved for the treatment of androgenetic alopecia and benign prostate hyperplasia. In some patients the treatment is associated with adverse side effects that could become persistent after therapy discontinuation, resulting in the so-called post-finasteride syndrome (PFS).

Erika Cecchin, PhD, Experimental and Clinical Pharmacology Unit CRO National Cancer Institute, Pordenone, Italy


Irwin Goldstein

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.

Irwin Goldstein, MD, Editor-in-Chief of the Journal of Sexual Medicine