Post-Finasteride Syndrome: What is It?
If you’re dealing with male pattern baldness, there’s a good chance you’ve heard of or are currently using finasteride. You also may have heard about rumoured side effects of the medication, like finasteride insomnia or other long-lasting impacts of this common hair loss treatment. That’s because, like any medication, finasteride can cause side effects, and in very rare cases, those side effects may persist, which is referred to as post-finasteride syndrome or PFS syndrome.
A very small percentage of men claim to develop post-finasteride syndrome symptoms after taking finasteride. While these cases exist, PFS isn’t officially recognised by most of the medical community.
Continue 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.
What Is Finasteride?
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 also 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. Our guide to DHT and male hair loss extensively explains this process and its effects on hair.
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 can either slow down, stop, or even reverse hair loss caused by male pattern hair loss.
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What is Post-Finasteride Syndrome?
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)
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 the more commonly reported side effects of finasteride, the adverse reactions associated with post-finasteride syndrome can continue after someone stops taking the medication. 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.
How Common is Post-Finasteride Syndrome?
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?
Well, 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, 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 federally-run department 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 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 who 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 rates between the men who received finasteride and those 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. Only 1.2 percent of men who participated in finasteride clinical trials stopped using their medication because of adverse effects. However, the findings do raise questions about the theory that finasteride has the potential to cause lasting, long-term, severe side effects.
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. Other issues, such as selection bias, are 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 several different factors could cause the symptoms commonly described as post-finasteride syndrome.
The first is the nocebo effect, 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.
A 2023 study found no increase in suicidal behavior in men treated for BPH with finasteride versus another common medication, dutasteride. However, men with a history of mood disorders who were treated with finasteride showed a slightly increased risk of self-harm. This is part of the reason why it’s so important to be transparent with your doctor about your mental health, even if it seems irrelevant to treating something like hair loss.
Additionally, many 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 are most likely to develop noticeable male pattern baldness. Fifty percent of men will experience hair loss by the time they reach 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 be associated with 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 are just incidentally associated with finasteride use.
Overall, although there are many incidental reports of post-finasteride syndrome online and in popular media, there isn’t much high-quality scientific evidence to support its existence, at least not like there is for other medical conditions.
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
Although research overwhelmingly shows that finasteride is safe and effective, it’s understandable to have concerns about using finasteride to treat pattern hair loss.
Finasteride is currently the most effective treatment for hair loss available, but there are other actions you can take to tackle signs 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. Some of the most popular options include 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 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.
Although vitamins don’t play a role in preventing male pattern baldness, many vitamins are vital for proper hair growth.
Use Topical Finasteride Instead of Oral Finasteride
You might consider using topical finasteride to treat your hair loss instead of the pill version.
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, and 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
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. While it is not recognized by much of the medical community, it is 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.
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 or medication.