The Current - The rare but life-altering side effects of hair loss drug finasteride

Episode Date: March 25, 2025

Lots of men who take finasteride for hair loss notice results and no ill effects — but an investigation by Radio-Canada’s Enquête heard from dozens of men who experienced negative, life-altering mental, sexual and physical side effects. Brigitte Noel, a reporter who worked on the investigation, explains the toll those side effects can take, and how taboos around men’s health have made it harder for some to seek help.

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But it's time to imagine what we can do with more. Join Scarborough Health Network and together, we can turn grit into greatness. Donate at lovescarborough.ca. This is a CBC podcast. Hello, I'm Matt Galloway, and this is the current podcast. My world was turned upside down. I was in pain.

I could not think clearly. I did not have any motivation to do anything. And I was in pure survival mode. I could barely leave my bed. I could barely leave my apartment. I would say anybody who spent even just 10 seconds in my mind, in my body at that period of time would say that that is probably hell on earth. Wei Wang is talking about how he suffered after taking finasteride, a drug advertised as a treatment for male pattern baldness, also known by the brand name Propecia.

Most men find their hair stops falling out when they take it, and they have few adverse side effects. But for some, the side effects can be debilitating. Radio Canada's investigative program Enqu, has looked into these rare cases. Brigitte Noel is the reporter on this story. She joins us from our studio in Montreal. Brigitte, great to have you with us. Good morning, Marc.

Tell us a little more about finasteride. So finasteride is a medication that was developed in the early 90s by a pharmaceutical company, Merck. It was intended initially to treat prostate enlargement, a condition that is usually experienced by older men. It can make urination difficult. But when they were doing the trials for this drug, which was called Proscar, they noticed that patients were having an unexpected

side effect. Their hair loss was subsiding, new hair was growing. So they jumped at that opportunity, and in 97, 98, they patented a different version of the drug. So a smaller dose they called Propecia, which would be, is used to curb hair loss. So that drug has become incredibly popular. In Canada, in 2023, there were about 1.8 million prescriptions, and in the US, that number is closer to 10

million. Wow. So how do people get it? What does it take, then, to be a patient? Not much is what we discovered. People traditionally can go to see their general practitioner or their dermatologist to get it, but you don't really need to even be losing your hair. You can say that you want it as a preventative measure. And one of the reasons it's become so popular now, according to the people we

spoke to, is because it's now accessible through a whole slew of online pharmacies or telehealth sites that claim to be focused on men's health. I'm sure you've seen them on social media. And what we found in our investigation is that some of these sites are not necessarily very forthcoming about the risks of this medication What are those the side effects or the risks that would be most common? Well, the ones you hear about the most and these I have to say are highlighted in the information pamphlet that accompany the drugs They're erectile dysfunction loss of libido ejaculation disorder Condition called gynecomastia where men can also grow

breasts. In the last few years, Health Canada has also added the risk of depression, suicidal ideation, and self-mutilation to those warnings. Also worth noting that women who may be pregnant or who want to be pregnant shouldn't even touch finasteride as it can cause deformities in male fetuses. Wow. And in your investigation, you focus on something called post-phenasteride syndrome. Just what exactly is that?

Okay. So what's important to know about phenasteride side effects is that it's recognized that some can continue after one stops taking the drug. The risk of persistent side effects is written in the warnings that accompany the drug in Canada. But post-fertilized-storide syndrome is the name given to a condition where these symptoms continue on more than three or five months after a patient has stopped the drug. It is a little-known condition. It is rare. Some doctors consider it controversial, but it's getting more and more attention, both in the media and in the scientific community. So in the World

Health Organization database that catalogs reports of drug side effects, there are around 20,000 men worldwide who say they've experienced side effects from this drug since it was launched. And in our investigation, we spoke to 25 men. Most of them said they suffered from post-phenasteride syndrome, that they experienced all of the common side effects I just mentioned, but also a plethora of other symptoms and some of these symptoms came on after they stopped the drug. So their skin changed texture, their muscles hurt, their genitals shrunk, they became insomniac, anxious, their emotions became dulled with a horrible condition called anedonia, which

they described as the inability to feel joy or pleasure. And these men wanted to speak out to us because they see that this drug's popularity is increasing and they fear that more finasteride out in the world also means more cases of post-finasteride syndrome. And, Rashida, I'm curious to know, how did you hear about this in the first place? We did a story last year about the side effects of benzodiazepines, so sleeping pills, and so we got a record number of emails after that story from people who say that once they stopped benzodiazepines, they had long- side effects because it was difficult to taper and that launched a whole discussion in our inbox from people flagging different medications

that have either issues with withdrawal or side effects that last after you stop taking them and so one of those drugs that was brought to our attention was finasteride. You mentioned the manufacturers, Merck. What does the drug manufacturer say about the prevalence of these serious side effects? They've always maintained that it's rare and they've often argued that because some of the side effects begin after men stop taking the drug that it couldn't be possibly tied to the medication. We tried to ask further questions, but Merck refused our interview request. They

sent us over to their spin-off company called Organon. They transferred ownership of Propecia to them in 2021. Organon sent one paragraph in response to our multiple questions. They maintained the drug is safe. They say Health Canada has approved it, that they continue to monitor its safety through post-marketing reports. Post-marketing reports, that's important to retain. That's data that comes in once a drug is put to market and launched into the world. It's important to pay attention to any kind of signal that the drug might be causing rare or unexpected side effects because you're out of the controlled clinical trial environment.

So essentially, the company has long maintained that the side effects are rare and that they disappear once you stop the drug. But what did your research find out? So in several countries, there have been hundreds of men who have filed lawsuits against Merck, and these filings were very informative to our investigation. So for instance, we found that Merck considers that these post-marketing reports, what I just mentioned, are unreliable and difficult to interpret.

That's their language. And so they don't seem to be taking those that seriously. In fact, cases where the symptoms manifested a certain time after the patient stopped the drug were sometimes disregarded. But concerning the incidence of side effects, everybody who takes a medication wants to know the percentage of odds of side effects happening to them. And on the label for Propecia, it says, the incidence of each sexual side effect decreased to less or about 0.3% by the fifth year of treatment with Propecia, which is kind of a funny sentence.

And what we discovered in these court documents, what an American journalist from Reuters got access to in 2019 are internal emails from Merck exchanged by their employees that cast doubt on that 0.3% figure. So essentially, in those exchanges, the Merck employees say that this statistic is misleading their language. They say that to get such a low number, Merck only accounted for the men that were still taking the drug in the fifth and final year of clinical trials. So that means that all the men who in the years previous had perhaps left the trials because of sexual or other side effects, they were not included in that final tally.

And so that is what the Merck scientists say is misleading. And these filings, these core documents, these emails also allege that in the early 2000s during clinical trials, Merck noticed that some participants were experiencing persistent side effects that were continuing after they stopped the drugs, but they didn't follow up with these men, they didn't issue a public warning according to these filings. They only changed a few words from their product monograph. So where it used to say, resolution occurred in all men who discontinued therapy. It now says, resolution occurred in men who discontinued therapy.

Now Merck told Reuters that these emails were taken out of context. The case was settled out of court. So none, there was no further debate about these allegations. But we spoke to a dozen doctors and researchers who've looked at finasteride side effects, who've looked at these studies, and many told us they believe we don't actually have any accurate data on the drug safety. In the hearts of our neighbors. The eyes of our nurses. And the hands of our doctors. It's what makes Scarborough Scarborough. In our hospitals, we do more than anyone thought possible.

With less than anyone could imagine. But it's time to imagine what we can do with more. Join Scarborough Health Network and together, we can turn grit into greatness. Donate at lovescarborough.ca. At Desjardins, we speak business. We speak startup funding and comprehensive game plans. We've mastered made-to-measure growth and expansion advice,

and we can talk your ear off about transferring your business when the time comes. Because at Desjardins Business, we speak the same language you do, business. So join the more than 400,000 Canadian entrepreneurs who already count on us and contact Desjardins today. We'd love to talk business. We heard in the introduction a bit of what Wei Wang experienced after taking finasteride

and I know he's with you in studio, Wei, good morning. Good morning. Tell us, why did you start taking this drug? I started taking the drug probably for the same reason the majority of men start taking the drug. They notice a bit of thinning maybe in their hair, and maybe it affected their self-esteem. It certainly affected mine,

and that's when I decided to take the plunge. Who told you about this or how did you hear about the drug? So I first got a consult with a hair transplant surgeon. She was the one who informed me that I was being very hasty in considering such an operation and that there are plenty of very safe, allegedly safe, you know, medical treatments. And one of the ones she recommended the most strongly was finasteride. Okay. And did she tell you about any potential side effects? She did.

She mentioned, you know, kind of the sexual side effects, potential to lose libido, potential to have erectile dysfunction. But most importantly of all, she stressed that these side effects would be transient, that once you stop taking the drug, it all goes away. There was no risk as far as she was concerned to take the drug. You're a young man. I believe you're 29 years old. That's correct.

Did at that time, was that worth the risk for you? I mean, you know, when you hear that side effects are transient, you kind of perceive that there really is no risk, right? I mean, what's the worst case scenario? You experience some side effects, you stop, your life goes back to normal. Unfortunately, that is not the case. But no, I did not see that it was even a legitimate risk.

So when did or how did you first realize that things were not going right? So I used a very low dose topical finasteride solution. And, you know, that gave me even more confidence that I would not suffer from any side effects or, you know, persistent issues or anything like that. And, you know And it kind of just shows that there's no such thing really, at least in my experience, as a safe dose of finasteride. But that's a different question. I took it for 10 days. Within that period, I was getting some of the sexual side effects.

I was getting pain in my genitalia. And at the, you know, the kind of recommendation of that doctor, I stopped taking it after the 10th day. And it was immediately the next day, the morning after I stopped where everything just, you know, changed for me in an instant. I woke up and I was, you know was having some sort of panic attack. I was in severe distress. My body was burning. It was physically burning. I knew something was wrong.

The first thing I wanted to do was cry. I generally have very good emotional regulation and it was all over the place. That was the first sign that things were going wrong. And over the period of probably three to six months after that, I continued to develop, you know, various side effects, physical, psychiatric, neurological, sexual side effects brought on overnight after stopping the medication. Wow.

And what did it take for you to get diagnosed then with post-phenasteride syndrome? It's a very interesting question to answer. The reality is when I went back to the hair transplant surgeon to report my symptoms, her initial reaction was to question whether I was going through a stressful period in my life, you know, kind of putting back on the patient to suggest that, you know, it's just unrelated to the medication. But after a brief discussion, she did say that, you know, she has seen that before in a different patient who had maybe emotional challenges after using finasteride. And over the course of some discussion, she mentioned that, you know, it took probably

three to four years for those to improve or resolve for that person. So she was the first one to put into my real awareness that post-fenasteride syndrome was possible, despite the fact that she had advised me that there are no risks. And then, of course, I went to my family doctor who initially was extremely skeptical, and I don't blame him because, you know, in the literature, it really doesn't seem like something that is, you know, well understood or kind of widely known. But you know, over time, because of the chronology of how my symptoms developed, I believe he came around, you know, he also gave me, because I had to take medical disability. The degree of my symptoms was so severe, I had never

really taken extended time off work and in the past, I want to say 17 months, I took eight months off work as a result of post-fenasteri syndrome. And when he filled the form for me, he wrote the primary diagnosis as post-fenasteride syndrome. I also then since saw some specialists, two of them in the United States, who both also diagnosed me quite quickly with post-fenasteride syndrome because they had treated probably, in their words, over hundreds of patients that have developed this condition. Wow. Brigitte, for your investigation, you spoke to two dozen men about their experiences. So how does Way's story stack up against those?

It's unfortunately incredibly similar to the other stories we heard. Men who said their lives, their jobs, their marriages had been upended by this drug. And I have to underline that these men are all very different. Some started taking the drug in the early 2000s, others just last year. Some were in their late teens, others in their early 40s. And all of these men say they weren't properly informed about the risks of possible persistent side effects. And most of these men say that when they went back to their doctors to tell them

about these side effects, they weren't believed. And so a lot of them ended up seeing a lot of experts, a lot of specialists and doctors outside the country. Let's hear from another one of the men in your documentary. This is a man called Tom. This isn't the case for everyone, but the sexual side effects for me have mostly been corrected with the exception of infertility. So I'm still infertile.

I still deal with depression and motivation. And I feel like I'm never going to see justice for this. I had a piece of me taken away by a drug company when they knew that that could happen, when they didn't inform me that I'll never get back. And it's heartbreaking to hear what heartbreaking I was. I watched the documentary last night, but Brigitte, from the men you've talked to, how long do these symptoms last? What's devastating is that some of these men have been struggling with this for decades. There have been some who've shared certain improvements.

It's not completely hopeless, and there are some studies being done to try to find the reason this happens and the cure for it, but it's a very long process for some of these men. Anthony Comegna Wei, how about you? How are you now and have the symptoms gone away? Wei Chen The symptoms have improved, I would say, over time.

They've definitely not gone away. I am now one and a half years off of the medication, um, of the low dose topical solutions. So it's, uh, it's, it's very difficult to believe, to be honest with you. And what, what's has been the impact on the quality of your life? It's been dramatic. I mean, it's, uh, you know, it's, it's across the board, right? The symptoms are truly multi-systemic. Uh, you know, I have, I have neuropathic pain daily.

I have digestive issues, sexual dysfunction. You know, there's just – there's pain, there's discomfort. You know, there's not a single day that goes by after discontinuation that I'm symptom-free and that I don't think about the fact that I'm afflicted by this condition. But shit like we know how this process works. The regulatory process here in Canada is overseen by Health Canada. So what has Health Canada done to alert people about the possible side effects of these drugs? Well Health Canada has asked finasteride producers to update the drugs warning a few times. I say finasteride producers because it's now generic, so there's not just Merck, there's

other companies involved. And so the warning has been updated time and time again. We asked them if they thought that was enough, and in an email they said that these updates should now allow doctors and patients to have thorough discussions, essentially punting the responsibility to physicians. However, European regulators are currently re-examining the safety of finasteride, which could lead to a review of the drug's prescription guidelines, and Health Canada did tell us that they're keeping an eye

on this conversation. But Brigida, as I watched your documentary, your investigation, I was struck by the fact that there seems to be a hesitation, though, for some doctors to actually talk about this openly talk about The potential you know devastating side effects openly. Why is that? Why doctors are hesitant they might not fully know about them What's interesting to us is that often these drugs will be prescribed by dermatologists, but the side effects are

Sexual or psychiatric. And so men will go see other specialists. So there's this kind of disconnect between the prescriber and the person that ends up dealing with the symptoms and that creates an ecosystem where the men are not believed or the dermatologists continue to think that this drug is risk-free. But it's also, this is a story about a lot of taboos, right? So it's hard for men to talk about the fact that they were perturbed about their hair loss and they turned to this drug.

It's hard for men to discuss things like sexual dysfunction. So a lot of people who are affected by this are not necessarily talking about the fact that it's happening to them or might not make the connection between their symptoms and the drug. A lot of the emails we got after we broadcast our story were from men saying, like, I didn't understand why I was feeling like this and you just put a name on it and I don't know. You know, it was informing them of what they were feeling. And so for this reason, a lot of experts we spoke to say that this is just the tip of the iceberg.

Yeah, you mentioned that in the doc, the tip of the iceberg. And I was curious about that since this was broadcast, have you heard from other people who now didn't realize what was going on with them and now realize that it could be related to this drug? Absolutely, and those have been devastating emails because they're difficult to respond to. Just to give a bit of hope to anyone out there that is perhaps stressed out by this conversation. There are studies happening in the world, researchers are looking into the cause and a possible cure for this, but what's important to underline is that there's very little funding for this type of research that looks into the side effects of a medication or health

system doesn't seem to be structured to finance that work. And so these studies exist, they're happening mostly in Europe, and they're mostly funded by patients themselves. Wei, I want to know, what do you think other men should know before taking finasteride? What a question. I think everyone should acknowledge that the side effects are not transient in these rare cases. And anything is rare until it happens to you. And if it could happen to me, it could happen to anyone. And really don't take the risk because we're not talking about – I think the usual characterizations of the side effects are not accurate.

When they talk about erectile dysfunction or anxiety or depression, this is really making light of the situation. The reality is far more sinister. And as Tom very rightly said, it takes a piece of you out of you and you lose your humanity. Yeah, that's what I would say. And Wei, have you heard from other men who have gone through a similar experience? Very often. I'm moderately active on an online forum on post-phenasteride syndrome and what breaks my heart is that probably every week I'm getting a new message from a man who

either newly developed the condition or they've been struggling with it for a very long time and they're looking for someone to just you know bounce ideas off of and confide in. It's a yes It happens all the time. And are you angry that you weren't warned of potential side effects from the outset? I mean yes, I don't think anger is an emotion that helps the situation, but of course. And do you think that men should just accept that baldness is a natural part of aging? I mean, it's a very tough question to answer, right? I think everyone should make their own risk benefit analysis. I think everyone should be given the right information. I think a critical factor here is that people are not being given accurate information and

they're being misled into thinking there's no risk. And that is really the crux of the issue. So I think everyone should decide for themselves. Okay. It's a powerful investigation by Ankat. Thank you both for coming in to talk to us about it this morning. Thank you. Thank you for giving us a voice. Brigitte Noel is an investigative journalist with Radio Canada's investigative program Enquete.

And Wei Wang experienced rare side effects from the hair loss drug finasteride.