Initial Ideas - Working from First Principles

Hi All,
Since I’m new here (and new to PFS in general), I thought I would work back through the first principles of what may be happening to us. I think it might be a good exercise for many of the tenured and jaded here, and it may just prompt some new lines of inquiry for some sufferers.

It seems to me that there are a few disparate pathologies at play here:

  1. There are those who develop PFS rapidly upon a dose or two–this is pure speculation but it seems somewhat reasonable to assume that these folks have a genetic predisposition to be permanently affected by any type of 5AR inhibition. The drug effectively turns off some 5AR activity permanently or quasi-permanently.

  2. There are those that take it for a moderate amount of time, develop symptoms while on the drug, discontinue it and see a potentiation of those same symptoms, possibly due to some over-swinging of the 5AR pendulum or due to some pathologic 5AR damage.

  3. There are those who take the drug without symptoms or with mild symptoms for variable lengths, quit, and develop symptoms. This again could be due to an overcompensation of 5AR activity or an up-regulation of 5AR metabolite receptors with no sensitive feedback loop. (I count myself as part of this group)

  4. And there are those that take it for prodigious amounts of time, and either never quit and can function relatively normally or do quit at an advanced age and experience a complete system shut-down.

Now, there are only a finite number of things that could be wrong with us as a direct result of the drug (not counting second order ramifying effects from our primary symptoms). We know that 5AR catalyzes and modulates these specific reactions:

Cholestenone → 5α-Cholestanone
Progesterone → 5α-Dihydroprogesterone
3α-Dihydroprogesterone → Allopregnanolone
3β-Dihydroprogesterone → Isopregnanolone
Deoxycorticosterone → 5α-Dihydrodeoxycorticosterone
Corticosterone → 5α-Dihydrocorticosterone
Cortisol → 5α-Dihydrocortisol
Aldosterone → 5α-Dihydroaldosterone
Androstenedione → 5α-Androstanedione
Testosterone → 5α-Dihydrotestosterone
Nandrolone → 5α-Dihydronandrolone

So there’s only a handful or permutations of disordered 5AR substrate and metabolite concentrations that could explain our first-order symptoms. Namely, we ought to test all of the first column endogenous hormone levels in our body, and all of the second column metabolites (or any other compound that is able to portend by proxy these concentrations).

I’m sure previous users have gone this route, but I’m curious whether they have (a.) done extensive enough testing in this space and (b.) if anyone has utilized an endocrinologist to impute 5AR efficiency and output scores from the ratio of these chemicals.

Two confounding variables that I believe make PFS especially tricky are that (1.) an upregulation of tissue-specific receptors for these metabolites occurs as an intuitive physiological response to their underproduction while we were on Finasteride. This doesn’t appear easily reversed and may indicate that these tissues are receiving too much of the intended signaling molecule. Relatedly, (2.) many of the second-column metabolites are biphasic in nature, so that an over or an underproduction of that specific chemical can cause the same symptoms. To instantiate that point, some PFS sufferers have the same mental symptoms as me (brain fog, altered consciousness, vision acuity issues, and head pressure), yet they only took one dose. I, on the other hand, took it for 3.5 months without symptoms and developed them only upon cessation. I may be experience an over-production of allopregnanolone, for example, (or normalized production but higher tissue sensitivity from more receptor density) while the one-dose crowd may be experiencing an under-production of the same molecule. Its biphasic nature effectively renders us the same symptoms.

The varied constellation of symptoms could be due both to genetic propensity towards tolerance in varying tissues and also to pre-fin hormone levels. I’m very curious about those specific enzyme-catalyzed reactions above and how my intra-cranial levels of the cortisol and progesterone-based metabolites look. I’m very convinced that my isopregnanolone (which can influence saccadic eye movements) levels are quite sideways. In the coming few weeks, I have appointments to see an endocrinologist, neurologist, and ophthalmologist. And I’ve done preliminary bloodwork with with my Internal Medicine Physician and evinced normal blood levels of testosterone, cholesterol, and thyroid hormone.

If anyone has had any previous success with this route of inquiry, please let me know and please add any thoughts you might have. I’m lucky in that cost is not much a concern for me so I’m going to pursue as many tests as possible and hopefully shed some light of what some of the underlying pathology may be.


Well for a newbie you been thinking it through :smiley:


I had no idea 5a-reductase was catalyzing so many reactions! OMG! What was everybody thinking? How reckless does one have to be to produce and market such a drug?

I recently wrote a somewhat long post that is not generating any interest. Maybe you can tell me what’s wrong with it?

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Ya I can have a look. I haven’t had too many interactions on what I’ve posted either. I don’t think there are that many active users here, and many are looking for quick, pseudo-scientific fixes rather than understanding why they’re suffering.
And I about the reactions–I know! It’s alarming all around. I’m mostly disappointed in myself for taking it in the first place. I did some pretty extensive research prior and was very circumspect about the whole thing but somehow still decided to take it anyways.


Hi, I guess a lot of people just don’t get the science behind it. I am one of those.
I have a real interest in understanding things but it gets too specific…
Plus I have read the forum extensively and especially like the 10 years ago posts and people have tried so many things, so many protocols.
I guess people like me feel not legit enough to interact but it is interesting people are trying to put it in perspective.

Have you heard of Viome?
I Should be getting my own results back soon. I’ll post results when I do. I took Accutane.
I myself have already had hundreds of tests over the years.

Treatment of male rats with finasteride, an inhibitor of 5alpha-reductase enzyme, induces long-lasting effects on depressive-like behavior, hippocampal neurogenesis, neuroinflammation and gut microbiota composition

We have had dozens and dozens of threads over the years where some variant of “someting is wrong with 5ar” has been proposed. There were at least three of them in the last couple of days that I remember. It’s what many come up with, because it makes intuitive sense at first considering Finasteride is a 5ar inhibitor and the reason we have these persistent side effects in the first place.

These ideas don’t explain some critical symptoms, however. For example, plenty of people report (rapid) loss of muscle and muscle strength. Look up the results of our survey! Some even report accelerated muscle loss after exercise. And I am not aware of any 5ar related mechanism that explains the loss of this critical androgenic tissue. Neither a lack of DHT nor neursteroids explain this symptom.

This has all been discussed many times before. While I appreciate when people are interested in trying to understand our problem, it is worth noting that this forum has a history of such debates that spans more than a decade and that over this period plenty of scientific research, directly or indirectly related to our problem, has been published. This is not properly reflected in such theories. For example, one of the most critical findings in “PFS” research was the overexpression of androgen receptors in penile tissues and in many “theories” this is not even mentioned in passing.

Fortunately, from over a decade of discussions and research a basic theory that can explain all symptoms and is in line with the scientific findings has emerged. So, there is no need to reinvent the wheel. Awor spelled it out again briefly a couple of months ago in this post: Androgen receptor overexpression and sensitivity to hormones reversed by epigenetic therapy that restores Pur-α to a transcriptional repressor complex of AR deregulated in HRPC.

Hopefully, with the Baylor results coming, or at least some of them (knock on wood), and Axolotl’s paper we will have more comfirmation of what is going on and have it all spelled out in depth, so that people won’t have to browse through over a decade worth of posts and won’t have to come with new “theories”.


a basic theory that can explain all symptoms and is in line with the scientific findings has emerged. So, there is no need to reinvent the wheel. Awor spelled it out again briefly a couple of months ago in this post: Androgen receptor (AR) overexpression and sensitivity to hormones reversed by epigenetic therapy that restores Purα to a transcriptional repressor complex (RC) of AR deregulated in hormone refractory prostate cancer (HRPC) | Journal of Clinical Oncology.

I think I can speak for the staff running this site when I say: we’re united behind this. We want a way to fix our problem. We’re long in the tooth on these forums and the days of endless theorising are done.


here is a very interesting reflection.
Intuitively, even though I have not really considered the finasteride problem, when I read that and other posts, you have an increase in the symptoms and side effects of stopping finasteride, I wonder if it is not because you do not do progressive withdrawal when stopped, which is violent and sudden for the body?
Because what you describe makes me think of the prolonged symptoms of benzodiazepine withdrawal …,

whereas we know that in France, most doctors give them as sweets, and stop them at once, pretending that there is no addiction, dependence, or tolerance, and no rebound without very progressive withdrawal …
but yes, it is…
I’m wondering about other molecules … like finasteride … or l iso.
Maybe that is wrong of course.

Salut Stéphane,

Les symptômes de la fina sont juste sournois et la fatigue, la baisse de moral peut être imputée à des tas de choses… La Fina est aussi assez facilement prescrite si tu mentionnes une inquiétude pour un chute de cheveux. Je pense que dès que tu as les symptômes, c’est foutu… L’arrêt ne change sauf une majoration des symptômes car ton corps est en burn out… Un mois et demi que j’y suis, c’est un enfer sans nom… Tous les jours je pense à mourir et je me sens comme un petit vieux de 70 ans… Horrible…

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yes, I understood, it’s the same thing with roaccutane, and of course they propose me finasteride after having tested on me 15 of the 30 molecules prescribed in dermatology, because of iatrogenics side effects … but I think that it can change some thing, the way it was stopped … we agree that once stopped, better not take it back.

It is not necessary to remain focused on its symptoms, it is better to walk outside when it is not too hot outside, the morning or the evening (we deviate from the subject …).

I work in a field, psychology, where there are many wrong theories. What usually makes a theory wrong is not that it cannot explain some of the observations but that it cannot explain all of the observations. In other words, the theory is not general enough, but it purports to be.

In order for this to happen, three things are usually true: 1) The scientists proposing the theory are not aware of the evidence not explained by the theory (or contradicting the theory). 2) Evidence not explained by the theory (or contradicting the theory) is known but is ignored or explained away as somehow irrelevant. 3) Evidence purportedly explained by the theory is in fact bent to fit the theory.

Importantly, if we are certain that a piece of evidence is true, it only takes one such piece of evidence to completely refute a theory that does not explain it. A single piece of contravening evidence is stronger than a theory explaining a million other pieces of evidence.

Scientists make the mistakes above for many reasons - often thinking they are doing their best, and sometimes because of ego. But more often then not, they would rather have a narrow and incomplete theory than no theory, which is what they would often have if they accepted all the available evidence. Their biggest sin, however, is intransigence in defending their narrow theory against contradicting evidence, when that happens. This of course prevents them from developing a better theory. Even the best scientists in the world, and in history, have fallen victim to this phenomenon.

I say all this as a reminder to anyone who aspires to have a complete theory of PFS. This includes me. Biology is immensely complex and we have only scratched the surface trying to understand it. This requires us to be very humble and very open minded.

I am now going to address some specific pieces of evidence that I believe are not adequately explained by, are brushed aside, or are otherwise not incorporated in the prevailing theory of PFS described above.

1. Muscle loss

We should be very careful to dismiss a theory or propound а theory solely based on a symptom as vague and capricious as muscle loss, as reported on this forum or in the survey.

Muscle loss, I believe, is a general and non-specific symptom that can happen to anyone regardless of PFS status. All it takes to have muscle loss is to reduce protein intake and/or to stop going regularly to the gym. Ask anyone who has ever built muscle and they will tell you how easy it is to lose muscle when you stop trying really hard to maintain it. I have personally gained and lost many kilograms of muscle many times over, before I ever had PFS, following only minor changes in my lifestyle, mainly having to do with protein intake.

I am not denying that people have lost or do lose muscle mass in PFS. That can happen for the reasons suggested above or because of reductions in Testosterone levels, as well as as a result of androgen insensitivity. That some people have low T levels is undeniable and this can affect muscle mass, even in the absence of androgen insensitivity.

In this context, it is important to appreciate that different people can have different presenting hormonal profiles with the same underlying condition, due to differences in other variables. The hormone system regulates a vast number of processes and involves numerous feedback loops. Changing one variable can change all the other. One such variable is body fat content, which may impact E2 levels, which may downregulate T levels, which may impact muscle mass, and so on. We can make causal attributions based on hormone profiles only if we carefully control for as many other variables as we can, which obviously we have not done.

I personally have preserved my muscle mass remarkably well, given my horrible diet and complete lack of exercise due to severe joint pain. Many times before PFS when I have had a diet as careless as what I have now, I have lost muscle mass faster than I have now. Three months ago when I had a sudden desire to work out after a temporary rise in libido following Tribulus supplementation, I was shocked to see how fast I was able to build muscle after only 3 sets of push-ups in one day. This has all been surprising to me, until I found out recently that I have extremely high levels of free T (as well as low levels of DHT). I certainly cannot make conclusions about androgen sensitivity (to Testosterone) based on this evidence, but I want to urge people to keep the door open to alternative explanations, which are definitely possible.

As regards the survey, we need to be very careful how results are interpreted. Despite what I said above about my muscle status, I am pretty sure I reported in the survey that I have had extreme muscle loss. It is true that I have muscle loss compared to my shape before PFS but the cause of the muscle loss is in all likelihood due, in my case, to changes in diet and exercise as I already pointed out. It would thus be a mistake to interpret my response in the survey as evidence for androgen insensitivity in PFS.

Further, muscle loss can be such a vague symptom that I probably would have reported it even if I didn’t have it, simply because I may have thought I was supposed to have it. This of course is the nocebo effect. We need to be aware that many symptoms reported in the survey are to some unspecified extent affected by this phenomenon.

Beyond me, I believe many people on this forum have reported that due to their regular fitness routine they are in the best shape of their lives muscle-wise despite PFS. This evidence cannot be easily dismissed.

Finally, lack of muscle loss would not necessarily be evidence against androgen insensitivity in general but may be evidence against Testosterone insensitivity in muscle. This does not preclude DHT or Testosterone insensitivity in other tissues such as the pituitary, the prostate or the penis.

But this changes the theory.

Coming up Next:

The Elephant in the Room…

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Nobody did that. It’s a strawman. Muscle loss was named as one example that cannot be explained by 5ar deficiency. There are plenty more. And even if you’d argue that some of the physical symptoms could in theory be attributed to a lack of DHT associated with some 5ar deficiency, then DHT supplementation should take care of these symptoms. But, of course, this has been tried over and over again and largely failed. Ultimately, there are plenty of physical symptoms that cannot be explained by altered neurosteroids associated with 5ar deficiency and that do not improve with DHT supplementation. How do you reconcile that with 5ar deficiency? You cannot.

With regard to muscle loss: Yes, that can happen for various reasons. But that’s true for almost every symptom. The rapid muscle loss many people describe is very different to muscle loss from lack of training or leaving out the protein milk shake. And no, it’s not a lack of Testosterone, either. Otherwise, Test supplementation would take care of it. Awor was on TRT and was into weightlifting, when he got PFS and suddenly his muscle mass was going away.

We also have people who don’t have libido issues. Clearly, the symptom profile is highly variable. Nobody dismisses that. It’s obvious that this condition is tissue specific. This is in no conflict to what I write.

Again, and that was the point of my post. This has all been discussed plenty of times before. And there is important evidence that was ignored in the original post. It’s great if people want to get a scientific understanding of this condition. Right now all the scientific community work is on the shoulder of two people. But it would be good if people would first try to get an understanding of what we already know and would not ignore a decade of progress.


I’m surprised by both the dismissive and divisive nature of the comments here. I think @Sibelio has made several noteworthy comments and critiques, and I think it’s unfair to criticize him on the premise that “Everyone has thought about all of this before and you’ll never uncover anything new.”

My sole intent with the original post was again to highlight that Finasteride affects the aforementioned enzyme-catalyzed reactions and that that is a good jumping off point for considering why we all have somewhat disparate yet seemingly related symptomologies and presentations. I thought that perhaps it may be a useful de novo approach. You’ll notice that I didn’t present much of a theory, but more of a capacious look at what reactions finasteride specifically inhibits and how those reactions could be affected after exposure. I’d also say that many users’ over-reliance on anecdotal data points is a bit alarming.

As for the discussion on muscle atrophy, a very reasonable explanation with direct relation to 5AR is hypercortisolism, which many sufferers seem to exhibit. It is also a direct consequence of the adrenal fatigue that many have countenanced as a result of Finasteride use.

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This topic is ringing all kinds of alarm bells for me.

If there’s one thing that I have learnt through my period of suffering with this condition it is that people absolutely wish to find a quick fix and will invest in pseudoscience. Both intellectually and financially. Our community is a very vulnerable one. We have been abandoned by the industry that put us in the position and seemingly do not have much assistance coming.

It’s extremely likely that @axolotl and @awor are the world’s authority on this subject. Certainly the most accessible experts. If you look at their posts on the subject (and I suggest that for any new poster looking to gain an understanding of the situation that is the best thing to do) then you will note that though their posts are very well written and easy to understand, that the incredible complexity of this problem is not to be underestimated. This is not something that can be grasped and understood easily.

Whilst I fully understand @thisisarealbummer’s interest in suggesting how we might understand the situation, it’s actually quite likely that the vast majority of people here just will not. Even if we have it worked out. Though a scientifically literate layman may understand how various processes work in the body, this is at a different level of complexity and to grasp the necessary concepts at work will require serious study. It will not be understood with some light reading and guesswork.

When I found myself in this position, I rapidly realised that there are many conmen, deluded people, good people in the world and that none of them, even the worst of them, deserve this.

The only way we can deal with this is to work together. We are mostly all we have. By all means, develop your ideas if you wish and of course you are free to discuss them (please report opinions as such, not as facts), but as @Northern_Star says, we have years of this sort of thing, at least do the background reading first. We have a search function if you’d like to see if something has been covered already, you might argue that continuing a conversation is better than starting a new one.

If that sounds patronising, I really, really don’t mean it to be but when I see

Followed by:

I see someone who hasn’t done their research properly.

You can’t speak from a position of decrying pseudoscience and then referring to it as fact. If you’re not sure, refer to consensus.

When I originally looked at this topic I skimmed it and thought it might go something like this, and I’m sad that it has. Not because it’s obvious that there’s no answers here, but because it represents the kinds of divisions that we as a community cannot afford. I understand why someone might want to believe in a topic like this and that theres no intentional malice here, but as @northern_sky says, it’s another groundhog day. This pattern will be repeated over and over for months or years. I’m not even sure if there’s any point in me posting because:

And our community struggle to take a long view on this.


The Elephant in the Room

I am sorry that I might ruin the dramatic effect, as I had planned and implied a somewhat longer story arc here, but I am going to be short.

Some people (many people, most people?) get PFS while they are on finasteride or after a couple of pills or after a single pill, before their androgen receptors were upregulated (although that’s not the key point) - when their DHT levels went down, not up.

I got PFS after a single 5mg pill when no doubt my DHT levels went massively down. Granted, my androgen receptors must have already been upregulated after I had previously been on finasteride for 8 years.

But others did not have upregulated receptors when they got PFS, unless one argues that eating tomatoes 5 year prior upregulated their receptors, which is entirely possible. Again, this is not the key point. The key point is that androgens went down, not up, when they got PFS.

What does that tell us? It tells us the dominant theory is not a general theory (unless I am not familiar with the entire theory, which is possible).

This is OK. It doesn’t mean all parts of the theory are wrong. It doesn’t mean receptors are not upregulated, it doesn’t mean there are no epigentic changes, it doesn’t mean there isn’t androgen resistance…

It means the theory may be missing some parts – which may be key parts that change the entire theory – and one such part may have something to do with 5a-reductase. Or maybe there is another missing piece not having to do with 5a-reductase.

If 5a-reductase is in fact a missing piece of the puzzle, for which there is some evidence, it doesn’t have to explain all the symptoms of PFS as there are other pieces in the puzzle. The puzzle is complex and the different pieces work together.

There seems to be some misunderstanding in the discussion above, most of all about the subject and purpose of the debate. For me, the subject of the debate is and should be finding out the truth about PFS. The purpose of the debate is to cure PFS.


What seems to be creating difficulties in creating a general theory is that some people get their persistent symptoms whilst taking the drug whilst others get them after stopping. It seems like most people with PFS already had PFS symptoms when taking finasteride, then they stopped, got better for a few weeks and then crashed, often resulting in much more severe symptoms. This crash fits in with the theory that androgen signalling gets silenced as a result of the extreme surge in DHT combined with AR hypersensitivity. However I personally can’t explain why it takes a few weeks before crashing, maybe someone else has a theory on this?

On the other hand I believe most people with PSSD (myself included) developed symptoms whilst taking SSRIs that simply never resolved, and didn’t experience any sort of crash. Therefore it seems possible that there are multiple mechanisms causing the same condition. Could SSRIs have the innate effect of methylating the genes involved in androgen signalling? We already know that serotonin downregulates AR. Perhaps very high levels of serotonin could silence androgen signalling.

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Has anyone had a muscle biopsy?
I was pretty close to getting this, but then I backed out because of cost and thinking it wasnt going to reveal anything, just like so many other tests.

Speaking of Fin,(I have never touched it, but took a strong course of Accutane when I was young) to me, its a drug or substance induced health issue, but maybe not specific to the drug itself.
For example, maybe a person forgets they took Propecia, then from there a person looks at solving the problem. Dont focus on the drug itself.
its kind of like alot of long term Accutane sufferers have focused on hypervitaminosis A and they feel they need to purge this from the body, even after 20 years. There’s even a youtube video on it.
This really hasn’t gotten us anywhere.
Im also familiar enough with the PFS groups that focusing on hormones hasnt lead to alot of definitive conclusions or treatment over the years either.

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My first year I would dream it wasn’t happening…then waking up I’d go back to that moment and be angry for taking it