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Post Finasteride Syndrome: What is It?

Knox Beasley, MD

Reviewed by Knox Beasley, MD

Written by Rachel Sacks

Published 10/09/2021

Updated 07/27/2024

If you’re dealing with male pattern baldness, there’s a good chance you’ve heard of or use finasteride. You also may have heard rumors about finasteride insomnia or other long-lasting impacts of this common hair loss treatment. 

That’s because like any medication, finasteride can cause side effects, often referred to as post-finasteride syndrome or PFS syndrome.

Although a very small percentage of men claim to develop post-finasteride syndrome symptoms after taking finasteride, PFS isn’t officially recognized by most of the medical community. 

Keep reading to understand what post-finasteride syndrome is, the symptoms associated with PFS, as well as the potential treatment options for both PFS and hair loss if you’re worried about developing post-finasteride syndrome.  

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Finasteride is a 5-alpha reductase inhibitor that’s used to treat androgenetic alopecia or androgenic alopecia (the clinical terms for male pattern baldness) and benign prostatic hyperplasia (BPH, an enlarged prostate). It’s sold as a generic and under the brand names Propecia® and Proscar®. 

As a 5-alpha-reductase inhibitor, finasteride works by inhibiting the effects of the enzyme responsible for converting testosterone into dihydrotestosterone (DHT).

Male pattern baldness develops when DHT binds to receptors in the scalp and causes hair follicles to miniaturize. We’ve explained this process and its effects on hair extensively in our guide to DHT and male hair loss

Research also suggests that DHT can stimulate the growth of cells in the prostate, contributing to benign prostatic hyperplasia.

By blocking the conversion of testosterone to DHT, finasteride treatment drastically reduces DHT levels in the body. 

Research has shown that finasteride cuts DHT levels in the prostate by upwards of 90 percent, and in the bloodstream by more than 70 percent.

This reduction in DHT greatly reduces prostate growth and either slows down, stops, or reverses hair loss caused by male pattern hair loss.

What is post-finasteride syndrome?

What is Post-Finasteride Syndrome?

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Post-finasteride syndrome (PFS) is a term that’s used to describe a range of persistent adverse side effects that occur in a small percentage of men who use the medication finasteride.

If you’ve experienced any of the following physical symptoms, you may be dealing with PFS, according to the Post-Finasteride Syndrome Foundation

  • Sexual dysfunction, including a decreased sex drive or complete loss of libido

  • Erectile dysfunction (ED)

  • Loss of “morning wood” and spontaneous erections

  • Peyronie’s disease (growth of scar tissue in the penis)

  • Shrinkage and numbness of the penis

  • Sexual anhedonia, or loss of pleasure from sexual stimulation and/or arousal

  • Ejaculation disorders, such as reduced ejaculatory volume and force

  • Shrinkage and numbness of the testes

  • Gynecomastia, or male breast growth and sensitivity

  • Chronic fatigue and lack of energy and enthusiasm

  • Muscle pain, weakness, cramps, stiffness, and twitching

  • Rhabdomyolysis (rapid breakdown of damaged or injured skeletal muscle)

  • Elevated creatine kinase levels

  • Dry, thinning skin and decreased production of sebum (an oily substance that products your skin)

  • Melasma (a skin condition that involves patches of dark, discolored skin)

  • Tinnitus (ringing in the ears)

  • Lipoatrophy (loss of fat tissue in specific areas of the body)

  • Increased body mass index (BMI) and fat deposition

  • Reduced HDL cholesterol levels, raised triglycerides and fasting glucose

  • Increased rheumatoid factor (proteins produced by the immune system)

  • Decreased body temperature

  • Optic neuropathy (damage to the optic nerve inside the eyes)

  • Ocular toxicity (drug-induced damage to the eyes)

  • Retinopathy (disease of the retina)

PFS is also said to involve mental and neurological symptoms. According to the Post-Finasteride Syndrome Foundation, these may include:

  • Reduced memory and difficulty recalling information

  • Impaired ability to solve problems and comprehend information

  • General cognitive impairment and slowed thought processes

  • Depression, anxiety, and/or suicidal ideation

  • Anhedonia (inability to feel pleasure) and emotional flatness

  • Insomnia (difficulty falling asleep or staying asleep)

  • Obstructive sleep apnea

According to the Post-Finasteride Syndrome Foundation, PFS may result in an increased risk of suicide attempts.

Unlike regular finasteride side effects, the adverse reactions associated with post-finasteride syndrome can continue after someone stops taking it. Some men with PFS report symptoms that last for years after finasteride discontinuation.

Many websites that discuss post-finasteride syndrome describe it as a lifelong condition with no treatments or cures.

According to the Post-Finasteride Syndrome Foundation’s FAQs page, there also aren’t any  known scientific reports of patients with PFS returning to full health.

Is Post-Finasteride Syndrome Real?

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Based on the symptoms and descriptions provided online, post-finasteride syndrome can seem like a severe, untreatable condition.

This is understandably concerning for many men with male pattern baldness or benign prostatic hyperplasia who are considering finasteride as a treatment. 

After all, if the long-term side effects of finasteride are potentially much worse than going bald, why use it in the first place?

When it comes to the side effects of medication, especially severe ones, it’s important to look at data objectively. 

Although the symptoms of PFS are alarming, it’s important to keep in mind that they are incredibly rare — even in long-term finasteride users.

Finasteride Research

Like other medications, finasteride went through several large-scale clinical trials before it received approval from the FDA (the federal gov body that assures the safety and efficacy of medication, medical devices, food, cosmetics, and more). 

In these trials, researchers found that finasteride can cause several of the side effects mentioned above, including decreased libido, erectile dysfunction, and ejaculation disorder.

However, only a very small percentage of men who used finasteride at the 1mg daily dose that’s used to treat hair loss experienced any of these side effects. 

For example, in a one-year trial, men with male pattern baldness who were treated with 1mg of finasteride per day reported the following side effects:

  • Decreased libido (reported by 1.8 percent of men)

  • Erectile dysfunction (reported by 1.3 percent of men)

  • Ejaculation disorder (reported by 1.2 percent of men)

At first glance, this may look concerning. However, many men who were treated with a placebo medication also reported the same side effects:

  • 1.3 percent of men who received the placebo reported decreased libido

  • 0.7 percent of men who received the placebo reported erectile dysfunction

  • 0.7 percent of men who received the placebo reported ejaculation disorder

A similar trend occurred in trials of Proscar, a 5mg form of finasteride that’s used to treat BPH.

After using finasteride at a 5mg daily dose for one year, men reported the following side effects:

  • Erectile dysfunction (reported by 8.1 percent of men)

  • Decreased libido (reported by 6.4 percent of men)

  • Decreased ejaculatory volume (reported by 3.7 percent of men)

  • Ejaculation disorder (reported by 0.8 percent of men)

  • Gynecomastia, or male breast enlargement (reported by 0.5 percent of men)

  • Breast tenderness (reported by 0.4 percent of men)

Like in the above trial, men placed in the control group received a non-therapeutic placebo. The men that received the placebo reported similar side effects:

  • 3.7 percent of men who received the placebo reported erectile dysfunction

  • 3.4 percent of men who received the placebo reported decreased libido

  • 0.8 percent of men who received the placebo reported decreased ejaculatory volume

The other side effects, such as ejaculation disorder, breast enlargement, and breast tenderness, were only reported by 0.1 percent of men who received the non-therapeutic placebo.

Over the long term, the differences in side effect rate between the men who received finasteride and the men who received the placebo became significantly smaller. In some cases, there was no difference in side effect rates between the two treatments. 

For example, during the second, third, and fourth years of the trial, 5.1 percent of men who used 5mg of finasteride daily reported experiencing erectile dysfunction. Among the men who used the placebo, 5.1 percent also reported experiencing erectile dysfunction.

The same pattern occurred with decreased libido, with 2.6 percent of finasteride users and 2.6 percent of placebo users both reporting this side effect.

Now, this doesn’t mean that finasteride itself can’t cause side effects. It can and does, although they typically aren’t common. It does raise questions about the theory that finasteride has the potential to cause lasting, long-term, severe side effects though. 

Within the medical community, there’s debate about whether post-finasteride syndrome is a real medical condition or something that’s largely psychological. 

Most of the research used to support the idea of post-finasteride syndrome is low quality, with issues such as selection bias believed to affect results. Because of this, most medical bodies do not officially recognize post-finasteride syndrome as a medical condition. 

Factors That May Contribute to PFS Symptoms

Experts believe that the symptoms commonly described as post-finasteride syndrome could be caused by several different factors.

The first of these is the nocebo effect. This is a psychological phenomenon in which a person’s negative expectations about a specific medication or procedure may cause them to experience a negative symptom.

For example, if a person is aware that a medication can cause headaches, they might become more likely to report experiencing a headache after using the medication.

This issue can have a serious impact on a person’s risk of experiencing side effects after taking medication, as clinicians and other healthcare providers are required to inform their patients about the potential side effects of medication as part of the treatment process. 

While this may sound unusual, research backs it up, and even shows that it’s a specific problem for men who use finasteride.

In a small study published in the Journal of Sexual Medicine in 2007, men with benign prostatic hyperplasia were divided into two groups and treated with finasteride.

The men in one group were informed that they would use finasteride and told about the sexual side effects associated with the medication. The men in the other group were not told that they would use finasteride and did not receive a briefing on potential side effects. 

The researchers found that the men who were informed about sexual side effects were around three times more likely to report experiencing ED, decreased libido, or ejaculation disorders.

In short, being aware that finasteride may cause sexual side effects is associated with a higher risk of actually experiencing these side effects.

A second factor that may explain the symptoms of post-finasteride syndrome is existing mental illness

Research has found that men who develop PFS generally don’t show signs of reduced 5-alpha levels or androgen deficiency, but do show symptoms similar to those in people diagnosed with depression.

Thirdly, a lot of the problems commonly described as symptoms of post-finasteride syndrome are common in middle-aged and older men, particularly men in the age group that is most likely to develop noticeable male pattern baldness.

Some research suggests that more than 50 percent of men will experience some form of hair loss by the time they hit 50 years old.

Many men also begin to develop sexual performance issues in middle age. Case in point: The rate of erectile dysfunction increases from just over eight percent for men in their 40s to more than 77 percent for men aged 75 or older.

There’s also a link between aging and a decline in testosterone levels. Since testosterone is an important hormone for sexual desire and function, this could cause a reduction in libido. 

What Finasteride and PFS Research Ultimately Shows

Researchers have theorized that the reported symptoms of post-finasteride syndrome may not be caused by finasteride itself, but just incidentally associated with finasteride use.

Overall, although there are lots of incidental reports of post-finasteride syndrome online and in popular media, there isn’t very much in the way of high quality scientific evidence to support its existence, at least not like there is for other medical conditions. 

However, we may soon see more data. According to the National Institutes of Health, scientific research is underway to “better understand the effects of 5-alpha reductase inhibitor drugs” like finasteride. 

As more studies are conducted, we may learn more about the possible link between finasteride and the reports of various long-term symptoms. 

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How to Treat Hair Loss without Post-Finasteride Syndrome Risk

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Although research overwhelmingly shows that finasteride is safe and effective, it’s understandable if you have concerns about using finasteride to treat pattern hair loss.

Finasteride is currently the most effective treatment for hair loss available, but  it’s still possible to take action and reduce the severity of hair loss without using finasteride. 

Below, we’ve shared methods that you can use to treat and prevent male pattern baldness while minimizing your risk of developing post-finasteride syndrome. 

Stick to Non-Prescription Hair Loss Treatments

One way to treat your hair loss without using finasteride is to use non-prescription treatments for hair loss, such as minoxidil, hair loss shampoo, and hair growth vitamins.

Minoxidil is a topical medication for treating hair loss. It’s available as a liquid and as a foam and is applied directly to affected areas of the scalp.

Minoxidil doesn’t block DHT. However, it can shift hair follicles into the anagen, or growth, phase of the hair growth cycle. It also improves blood flow to the scalp, which may help to supply your hair follicles with extra nutrients.

We offer minoxidil liquid and minoxidil foam online. Unlike finasteride, you don’t need a doctor’s prescription to purchase and use this medication. 

As for hair loss shampoos, many include ingredients such as ketoconazole and saw palmetto to block DHT at the scalp level

Our Hair Thickening Shampoo features saw palmetto to target DHT and prevent it from damaging your hair follicles. 

Although vitamins don’t play a role in preventing male pattern baldness, many vitamins are vital for proper hair growth. Our Biotin Gummy Vitamins are formulated specifically for healthier hair, skin, and nails. 

Use Topical Finasteride Instead of Oral Finasteride

You also may want to look into using topical finasteride to treat your hair loss.

Topical finasteride works at the scalp level rather than systemically, and research suggests it’s effective at treating hair loss.

We offer a combination Topical Finasteride & Minoxidil Spray that allows you to get the benefits of finasteride and minoxidil in a single medication. 

Consider Hair Transplant Surgery

Another way to treat male pattern baldness without using finasteride is via hair transplant surgery

This procedure involves removing DHT-resistant hair follicles from a donor area, such as the back of your scalp, then transplanting the grafted hairs to your hairline, crown, or other areas affected by male pattern baldness. 

Several different methods are used in hair transplant surgery, including follicular unit extraction (FUE) and follicular unit transplantation (FUT)

Hair transplant surgery provides permanent results, but it can be costly. You may need to have multiple procedures if your hair loss worsens. 

Plus, you’ll want to choose an experienced hair transplant surgeon to make sure you get satisfying, natural-looking results. 

It’s also worth noting that in practice, most hair transplantation surgery patients are treated with finasteride before and after the procedure.

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Understanding Post-Finasteride Syndrome

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If you’re dealing with male pattern hair loss or other men’s health conditions like BPH,, finasteride treatment is one option. But can you develop long-lasting symptoms if you start using a 5α-reductase inhibitor like finasteride?

  • Post-finasteride syndrome or PFS refers to a range of sexual, physical, and mental health symptoms associated with the use of finasteride as a treatment for hair loss and benign prostatic hyperplasia. It is not recognized by much of the medical community, but discussed frequently in online forums. 

  • Although finasteride can cause adverse events, there currently isn’t any high-quality evidence to show that these continue over the long term.

  • In general, side effects from finasteride — including persistent sexual side effects —  are rare, with only a small percentage of men affected at the typical finasteride dosage used to treat hair loss. 

If you’re concerned about post-finasteride syndrome, sexual symptoms, or other side effects, it’s important to discuss them with your healthcare provider before using finasteride. 

Alternatively, you can use other treatments, such as those available in our Non-Prescription Hair Loss Kit, to treat male pattern baldness without taking oral finasteride. 

15 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

  1. Zito, P.M., Bistas, K.G. & Syed, K. (2021, March 27). Finasteride. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK513329/
  2. Prostate Enlargement (Benign Prostatic Hyperplasia). (2014, September). Retrieved from https://www.niddk.nih.gov/health-information/urologic-diseases/prostate-problems/prostate-enlargement-benign-prostatic-hyperplasia
  3. About Post-Finasteride Syndrome. (n.d.). Retrieved from https://www.pfsfoundation.org/about-pfs-post-finasteride-syndrome/
  4. Frequently Asked Questions. (n.d.). Retrieved from https://www.pfsfoundation.org/frequently-asked-questions/
  5. PROPECIA® (finasteride) tablets for oral use. (2021, June). Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/020788s028lbl.pdf
  6. Trüeb, R.M., Régnier, A., Rezende, D.H. & Gavazzoni Dias, M. (2019, August). Post-Finasteride Syndrome: An Induced Delusional Disorder with the Potential of a Mass Psychogenic Illness? Skin Appendage Disorders. 5 (5), 320-326. Retrieved from https://www.karger.com/Article/Fulltext/497362
  7. Häuser, W., Hansen, E., Enck, P. (2012, June). Nocebo Phenomena in Medicine Their Relevance in Everyday Clinical Practice. Deutsches Ärzteblatt International. 109 (26), 459–465. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3401955/
  8. Mondaini, N., et al. (2007, November). Finasteride 5 mg and sexual side effects: how many of these are related to a nocebo phenomenon? Journal of Sexual Medicine. 4 (6), 1708-12. Retrieved from https://pubmed.ncbi.nlm.nih.gov/17655657/
  9. Basaria, S., et al. (2016, December). Characteristics of Men Who Report Persistent Sexual Symptoms After Finasteride Use for Hair Loss. The Journal of Clinical Endocrinology & Metabolism. 101 (12), 4669-4680. Retrieved from https://pubmed.ncbi.nlm.nih.gov/27662439/
  10. U.S. National Library of Medicine. (2020, August 18). Androgenetic alopecia. https://medlineplus.gov/genetics/condition/androgenetic-alopecia/
  11. Mulhall, J.P., Lou, X., Zou, K.H., Stecher, V. & Galaznik, A. (2016, December). Relationship between age and erectile dysfunction diagnosis or treatment using real-world observational data in the United States. International Journal of Clinical Practice. 70 (12), 1012–1018. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5540144/
  12. Badri, T., Nessel, T.A. & Kumar, D.D. (2021, April 13). Minoxidil. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK482378/
  13. Narasimhalu, C.R. (2016). Randomized Comparative Research Study of Topical and Oral Finasteride with Minoxidil for Male Pattern Androgenetic Alopecia in Indian Patients. Dermatology Clinics and Research. 2 (1), 77-80. Retrieved from https://www.scitcentral.com/article/19/60/Randomized-Comparative-Research-Study-of-Topical-and-Oral-Finasteride-with-Minoxidil-for-Male-Pattern-Androgenetic-Alopecia-in-Indian-Patients
  14. Rai, P.B., Khushwaha, P., Jain, N. & Gupta, S. (2018). Comparing the therapeutic efficacy of topical minoxidil and finasteride with topical minoxidil and oral finasteride in androgenetic alopecia: a randomized trial. International Journal of Research in Dermatology. 4 (3). Retrieved from https://www.ijord.com/index.php/ijord/article/view/394
  15. National Center for Advancing Translational Sciences. (2015, March 03). Adverse events of 5-alpha-reductase inhibitors. https://rarediseases.info.nih.gov/diseases/12407/adverse-events-of-5-alpha-reductase-inhibitors
Editorial Standards

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Knox Beasley, MD

Dr. Knox Beasley is a board certified dermatologist specializing in hair loss. He completed his undergraduate studies at the United States Military Academy at West Point, NY, and subsequently attended medical school at Tulane University School of Medicine in New Orleans, LA. 

Dr. Beasley first began doing telemedicine during his dermatology residency in 2013 with the military, helping to diagnose dermatologic conditions in soldiers all over the world. 

Dr. Beasley is board certified by the American Board of Dermatology, and is a Fellow of the American Academy of Dermatology.

Originally from Nashville, TN, Dr. Beasley currently lives in North Carolina and enjoys spending time outdoors (with sunscreen of course) with his wife and two children in his spare time. 

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