# Serotonin

Category: Hormones

Just friction, or scratching or stretching the intestine is enough to cause it to release serotonin into the bloodstream. Serotonin increases the permeability of the intestine and blood vessels, and so is likely to be a major cause of the absorption of endotoxin (and other…

12 passages · 3 authors · 2011–2026 · Most-cited: [Ray Peat](https://bioenergeticoracle.com/md/voices/ray-peat/index.md)

Canonical page: https://bioenergeticoracle.com/concepts/serotonin

## Synthesis

**Serotonin** is a systemic stress mediator whose elevation Ray Peat consistently linked to *low metabolic energy*, degeneration, and the aging process, directly contradicting its cultural branding as the “happy hormone.” [Source 1, 3, 5] Peat argued that the popular narrative was manufactured, tracing its origins to a misinterpretation of LSD’s mechanism; researchers found that LSD reduced serotonin, and when high doses caused psychosis, the opposite—that serotonin must promote sanity—became the entrenched dogma. [Source 2] He viewed serotonin not as a simple neurotransmitter acting on discrete receptors, but as a substance involved in **field-like formative processes** that shape how the organism adapts to stress, with its effects depending on the entire energetic context of the cell. [Source 5]

The synthesis and action of serotonin are intimately tied to **stress physiology** and **energy failure**. Peat detailed that the primary driver of brain serotonin synthesis is increased free tryptophan in the blood, which occurs when stress-induced lipolysis releases free fatty acids that displace tryptophan from albumin; this is exacerbated by hypoglycemia, not sugar consumption. [Source 1] At the cellular level, the rate-limiting enzyme tryptophan hydroxylase (TPH) is activated by excitation, increased intracellular calcium, and a *reductive cellular state*—a condition of low oxygen and glucose utilization that Peat identified as a common factor in shock and degeneration, challenging the exclusive focus on oxidative stress. [Source 1] Once synthesized, serotonin activates the pituitary-adrenal axis to increase **cortisol** and **prolactin**, hormones that further suppress mitochondrial respiration and promote tissue catabolism. [Source 6] Estrogen amplifies this system by increasing serotonin synthesis and inhibiting its degradation, while carbon dioxide and thyroid function act as the primary physiological antagonists, inhibiting serotonin release. [Source 1, 7]

Approximately 90-95% of the body’s serotonin is produced in the intestine, where it functions as a major mediator of inflammation and a link between gut irritation and systemic disease. [Source 9, 12] Peat explained that mechanical irritation of the intestine is sufficient to release serotonin, which then increases the permeability of the gut and blood vessels, promoting the absorption of **endotoxin** and other harmful materials. [Source 7] This gut-derived serotonin is a central driver of pathology; Georgi Dinkov has cited evidence that inhibiting gut serotonin synthesis with a TPH-1 inhibitor has the same protective metabolic effects as sterilizing the gut, identifying serotonin as the direct pathological agent downstream of bacterial overgrowth. [Source 10] Dinkov further notes that serotonin is a potent *profibrotic mediator*, with pharmaceutical companies quietly developing serotonin antagonists for fibrosis while marketing SSRIs that increase serotonin availability. [Source 8, 11]

The clinical consequences of elevated serotonin span from mood disorders to structural degeneration. Peat and Roddy have highlighted that every anti-serotonin drug has demonstrated antidepressant effects in animal models, and that the serotonin antagonist mianserin is approved for treatment-resistant depression, undermining the low-serotonin hypothesis of depression. [Source 4, 12] Roddy characterizes serotonin as a signal for *withdrawal and torpor*, promoting a state of discomfort and depression rather than alert pleasure. [Source 6, 7] Beyond the brain, serotonin’s profibrotic effects directly damage tissues; Dinkov describes how SSRIs accelerate degenerative mitral regurgitation by blocking the serotonin transporter, leaving excess serotonin to stimulate collagen overproduction in heart valves, a mechanism confirmed in both human observational studies and animal models. [Source 11] Peat identified serotonin as a major factor in osteoporosis and other aging-related degenerative changes, cementing its role as a central mediator of the structural decline that accompanies *low metabolic energy*. [Source 3]

## People also ask

### How does serotonin relate to stress and energy metabolism?

Peat argued that serotonin synthesis is driven by stress-induced energy failure, where lipolysis releases free fatty acids that displace tryptophan from albumin, increasing its brain uptake, while a reductive cellular state activates the rate-limiting enzyme for serotonin production.

### Why did Peat consider gut serotonin a driver of systemic disease?

The corpus describes how mechanical gut irritation releases serotonin, which increases intestinal and vascular permeability, promoting endotoxin absorption; inhibiting gut serotonin synthesis was shown to have the same protective metabolic effects as sterilizing the gut.

### What is the connection between serotonin and tissue fibrosis?

Georgi Dinkov noted that serotonin is a potent profibrotic mediator, with SSRIs accelerating heart valve degeneration by blocking the serotonin transporter, leaving excess serotonin to stimulate collagen overproduction, a mechanism confirmed in human and animal studies.

## Related concepts

- [Adrenaline](https://bioenergeticoracle.com/md/concepts/adrenaline/index.md)
- [Endotoxin (Lipopolysaccharide, LPS)](https://bioenergeticoracle.com/md/concepts/endotoxin-lipopolysaccharide-lps/index.md)
- [Prolactin](https://bioenergeticoracle.com/md/concepts/prolactin/index.md)
- [Age Pigment (Lipofuscin)](https://bioenergeticoracle.com/md/concepts/age-pigment-lipofuscin/index.md)
- [Albumin](https://bioenergeticoracle.com/md/concepts/albumin/index.md)
- [Aldosterone](https://bioenergeticoracle.com/md/concepts/aldosterone/index.md)

## Cited passages

Passage numbers match the `[Source N]` markers in the synthesis above.

### Source 1 — Serotonin: Energy, Degeneration, and Aging

Ray Peat · Newsletter · 2019

> Serotonin is the precursor for melatonin, which is important for adapting to darkness by promoting sleep to reduce stress. Mood is generally higher in the daytime (along with mental and physical abilities), so the advertising culture has to claim, despite the facts, that serotonin, the happy hormone, is higher in the daytime.
>
> Thinking about the events that lead to serotonin’s synthesis will clarify its place in the organism’s adaptive stress response system. Increased free tryptophan in the blood is the main factor determining the production of serotonin in the brain, and free fatty acids, produced by stress, cause bound tryptophan to be released from albumin in the blood. Hypoglycemia, resulting from many kinds of stress, leads to an increase of free fatty acids in the blood. Almost everyone in the US has heard the claim that sugar’s ability to cause relaxation and sleepiness is because it causes tryptophan to enter the brain, but in fact it is hypoglycemia, which causes irritability and anxiety, that increases the brain’s uptake of tryptophan (Yehuda and Meyer, 1984; Montilla, et al., 1988; Danguir, et al., 1984; Heyes, et al., 1990).
>
> The synthesis of serotonin in the brain depends on the activity of the enzyme, tryptophan hydroxylase, TPH, and this enzyme is activated by excitation of the cell, with increased intracellular calcium and reduced glutathione (GSH), and inactivated by oxidation of glutathione. Stress consumes glucose and oxygen, creating a relative hypoglycemia and hypoxia, and both of these are associated with reductive stress, increasing the formation of serotonin.
>
> **The cultural script that aging is caused by “oxidative stress” is being increasingly questioned, with the recognition of a reductive cellular state as a common factor in shock, stress, and degeneration.**
>
> The amount of serotonin in the brain at a particular time is influenced by a variety of things that affect the balance between its synthesis and its sequestration or degradation. The so-called serotonin transporter binds and holds serotonin, reducing its interactions with other cell components, and the enzyme monoamine oxidase, MAO, degrades serotonin, turning it into the inactive 5-HIAA. Many other factors besides its concentration affect serotonin’s effect on the brain, for example, the amount of dopamine.

### Source 2 — Things Are Getting Trippy: Serotonin & LSD In Context

Danny Roddy · Article · Dec 3, 2012

> **Danny Roddy:** [references] More than a year ago I wrote Serotonin: The Misery Hormone . And even though that article totally sucks, it's still one of the most visited on this site. Since then, I've expanded on serotonin and its role in stress, but the information is somewhat scattered. Because serotonin is a centerpiece in Dr. Peat's orientation, I thought I would write a new article aggregating the information with my ever-expanding "understanding" of Dr. Peat's work.
>
> **Question:** Serotonin huh? I hear that shit makes you feel real good!
>
> **Danny Roddy:** So let's get a few things out of the way: As confirmed by Serotonin's Wikipedia entry, its cultural identity is that of happiness The current generation of antidepressants (serotonin reuptake inhibitors, or SSRIs) bring in a cool 16 billion (b i l l i o n) dollars annually on the basis that depression is caused (at least in part) by "low serotonin" SSRIs have a horrible track record and may not work better than placebo If your SSRI works, it may reduce your libido, dissolve your bones, or radically increase the odds of you offing yourself In this article I will make the case that: Serotonin, in the real organism, is the exact opposite of its cultural identity (misery hormone) Serotonin's reputation may be due to the narcotic status of d-lysergic acid diethylamide (LSD) Serotonin, like estrogen, prolactin, and cortisol, is increased in stress, aging, and sickness Serotonin shares an inverse relationship with energy production and is strongly anti-thyroid Serotonin precursor supplements, 5-HTP and tryptophan, are dangerous

### Source 3 — EastWest Healing Serotonin and Endotoxin

Ray Peat · Interview · Aug 24, 2011 · http://l-i-g-h-t.com/files/east-west-serotonin-and-endotoxin.mp4

> **Josh Rubin:** What up everyone? This is Josh Rubin and Jeannie Rubin of Holistic Living. We're here today to share our radio show with Ray Peat. Today's show is on serotonin and endotoxin distress. Ray Peat is a teacher, educator, and researcher, and today he is going to school us on these topics. How are you doing, Ray?
>
> **Ray Peat:** Very good.
>
> **Josh Rubin:** How are you doing, Jeannie?
>
> **Jeannie Rubin:** I'm doing great, Josh. Thanks.
>
> **Josh Rubin:** Before we start, Ray, did you want to announce anything or add anything to your intro before we start talking about serotonin and endotoxin?
>
> **Ray Peat:** Not really. I've just been finishing another newsletter that includes stuff on serotonin. This one is on osteoporosis, and serotonin turns out to be a major factor in causing that and other aging degenerative changes.

### Source 4 — BV #3: Georgi Dinkov Responds To Estrogen Criticism, Serotonin Confusion, & Low Thyroid On Carnivore

Danny Roddy · Interview · Oct 30, 2024 · https://www.youtube.com/watch?v=m_PRMOVc7ww

> **Danny Roddy:** So speaking of torpor and lipolysis and cancer and estrogen and all the redox balance, Jay, do you want to set this video up of Dr. Berg talking about serotonin?
>
> **Jay Feldman:** Well, I think you set it up perfectly. Let's hear about serotonin as the happy hormone. You tell me when you want to stop. And all the things that we can do to increase it.
>
> **Speaker:** Serotonin, the happy hormone. What is serotonin and what does it do? Well, it's a hormone. A hormone is a communication that travels through the body. And serotonin is made by your brain. It's made by your gut. and it contributes to feelings of happiness it helps raise your mood it helps make you calm it decreases cravings for carbs it helps you focus and it reduces anxiety now if you're deficient in serotonin your mood might be suppressed okay you may have depression you may have anxiety you may be irritable you may even have worsened self-esteem sleeping problems and even memory loss so what can you do
>
> **Danny Roddy:** okay well i mean first the symptoms what uh what do you guys think

### Source 5 — Serotonin: Energy, Degeneration, and Aging

Ray Peat · Newsletter · 2019

> # Serotonin: Energy, Degeneration, and Aging
>
> Serotonin is often called a “neurotransmitter,” and considered to act on “receptors” to “transmit information,” which may be “processed” the way computers process digital information. I think it’s more useful to think of it in terms of fields and formative processes that shape the way the organism uses energy to adapt to stresses and possibilities. It is involved in the energetic and structural changes that occur during stress and adaptation. Getting rid of the misleading abstractions makes it easier to see some simple patterns that exist throughout the organism.
>
> The development of physics, beginning with calculations of the trajectory of cannonballs and the production of heat in boring cannons, has been guided by militarism. The development of genetics had ulterior motives, from Darwin’s assertion of the hereditary superiority of English people, plants, and animals, and Mendel’s denial of the mutability of traits, through Konrad Lorenz’s explanation of the need to exterminate inferior races. Medicine has been transformed by the influence of the pharmaceutical industry, including the popular understanding of serotonin that has been created by that industry.
>
> These three traditions—physics, genetics, and medicine—have interacted in ways that reinforce themes that favor the industries’ vested interests, and that eliminate themes that would harm their interests. For example, the major journals of “health physics” considering the biological effects of radiation are controlled by the nuclear industry, and have concentrated on heritable changes in DNA, rather than bystander and epigenetic effects, genetic stability, and behavioral and physiological changes. The situations in which the effects of ionizing radiation, estrogens, and polyunsaturated fats synergize have been shunned. The food and drug industries have found common interests in promoting the biological value of increased polyunsaturated fats, estrogens, and serotonin. Each of these has been featured in huge marketing campaigns. When studies of the biological role of one of these substances reveals its close biochemical interactions with one or both of the others, this is usually treated as though it confirms the importance of the study, because of the halo of cultural associations around each of them.
>
> The receptor doctrine is part of an ideological attitude toward life, an attitude that would like things to be clearly definable and uncomplicated.

### Source 6 — A Gentle Introduction to Dr. Ray Peat, w/@dannyroddy

Danny Roddy · Interview · Aug 25, 2022 · https://www.youtube.com/watch?v=qEUwUP69pGc

> **Russell Walter:** yeah well i i actually just you mentioning that there's this dude at a brazilian jiu-jitsu uh who's like super lean he's in like uh he's he's in his 40s he's super lean super muscular but i noticed like um sometimes like if it's a little colder like the dude will literally start shivering like almost uncontrollably to the point where he can't really participate and i remember looking at that and having like read you know your work and yeah it's like oh that's a that's not a good sign um but anyway yeah i think i think what you're saying is very interesting i like it it's a more holistic view and it is so true that some of the most unhealthy people you will meet uh uh physically or by appearance um yeah they could be in a quote-unquote good state but um i wanted to switch uh we'll speak about something else now i wanted to talk a little bit about um serotonin because you know a couple of these um hormones come up it's like serotonin thyroid cortisol um now In popular culture, serotonin is often like referred to as the happy hormone. If you are depressed and you go speak to your doctor or psychiatrist, they might prescribe you an SSRI, you know, serotonin reuptake inhibitor or whatever they're called. which will boost your serotonin levels. The idea being that that will somehow relieve your depressive symptoms. But I think that you have a very different view of serotonin.
>
> **Danny Roddy:** Yeah. I mean, that was completely inspired by Ray. You know, he has some classic articles on the subject and this goes back to hair loss, but one of the hormones that I was interested in was called prolactin. And it's like a pituitary hormone that in birds actually caused like the loss of feathers and things. And in the animal world, it's like not very controversial that it causes the loss of hair. so when i was in california i remember going to colleges and checking out these old textbooks where they all talked about prolactin and its loss of hair and animals but that that information is just like completely lost and barely ever talked about in today's like textbooks but anyways uh when i was getting into ray's kind of uh seeming the like his contrarianism When he was talking about serotonin, I was open to the idea, but then he started linking papers talking about how serotonin increased prolactin. And I was like, oh, well, that can't be good. And then serotonin activating the adrenals directly to increase cortisol. And I was like, that can't be good either. Like, there's no way you want to increase serotonin. And from my understanding, it's a really old... uh i don't know if it's necessarily a hormone i think it might be like a signaling substance or something but it's a really old substance that is produced primarily in the intestine not the brain and i think its basic function is to like expel the contents of the intestine if somebody eats something poisonous and so people with diarrhea and things will usually have very high levels of serotonin and anti-serotonin drugs like ciproheptadine or ondansetron or probably something other drugs can help stop that pretty quickly. But yeah, in old articles, I used to call it like the misery hormone, because it just seems to be involved in like, every bad aspect of life.

### Source 7 — Glossary

Ray Peat · Glossary

> Serotonin
>
> Just friction, or scratching or stretching the intestine is enough to cause it to release serotonin into the bloodstream. Serotonin increases the permeability of the intestine and blood vessels, and so is likely to be a major cause of the absorption of endotoxin (and other harmful material) during intestinal irritation or stress. The biological meaning of serotonin might be very different without endotoxin, but that hasn't been investigated.
>
> In the brain, serotonin regulates circulation and mitochondrial function, temperature, respiration and appetite, alertness and learning, secretion of prolactin, growth hormones and stress hormones, and participates in the most complex biochemical webs.
>
> The simple availability of oxygen, and the ability to use it, are regulated by carbon dioxide and serotonin, which act in opposite directions. Carbon dioxide inhibits the release of serotonin. Carbon dioxide and serotonin are regulated most importantly by thyroid function.
>
> Serotonin is a mediator of inflammation that suppresses metabolism, disturbs blood pressure, and promotes clotting, so it would be a Manichean-seeming misfortune if it was also essential to have lots of it to experience euphoria. But in reality a state of 'serotonergia' is a state of torpor, discomfort, and depression, rather than a state of alert pleasure.

### Source 8 — Animal-based vs. Ray Peat diet, a conversation with Georgi Dinkov

Georgi Dinkov · Interview · Dec 20, 2022 · https://www.youtube.com/watch?v=9ZM9sCfmAGc

> **Paul Saladino MD:** yeah yeah yeah it's so interesting i must be you know you're a geek and a nerd when when you get really excited about the menu at a blood work place and you're like what can i check you know i'm looking at this menu and i'm like oh i can get that oh man i could get all these cool little blood work things that's how you know you're a total geek let's talk about serotonin georgia we've kind of danced around this a little bit but you know in in my rotations in medical school you know in in mental health we give people ssris and i was like these drugs are you know there's this book the emperor has no there's like the i forget there's this book about the ssri thing you know that there's all these books kind of exposing this there was a big study that came out with ssris and uh like there's this general zeitgeist that serotonin is good and it's a happy drug but i've heard you speak a lot about the fact that this is not the way it is so let's let's kind of tell people the serotonin let's paint the picture of serotonin and kind of tie it into other things we've talked about because we keep mentioning it i want to make sure people understand serotonin what raises it we can even segue into a discussion of gut stuff and endotoxin if you want from serotonin but wherever you want to go
>
> **Georgi Dinkov:** So serotonin is a neurotransmitter, but apparently most of it is now about 90% is produced in the gut, the GI tract. Its old name was enteramin. So basically it was to recognize the fact that most of it is produced in the gut. And it was known, it actually has been known since the 1940s that elevated levels of serotonin are a very bad indication, typically associated with something called carcinoid syndrome. uh these people produce a lot of it and some of the symptoms of very high serotonin are diarrhea flushing constant flushing without any reason without any exertion right mental changes psychosis depression which by the way should immediately hold on a second how can medicine not medicine but how can the pharma companies tell me that serotonin cures depression when people with carcinoid syndrome are heavily depressed and psychotic sometimes right it's just these two just just just don't go well together um well i mean basically so there are there's plenty of others for specific conditions serotonin is pretty pretty bad uh in fact i think i mentioned as i mentioned earlier on the podcast uh the company pfizer despite selling you on that strider i forgot what the name of their the uh excel what's their lexapro Yeah, Paxil. Paroxetine, yeah. Yeah, whichever one Pfizer sells, it's still an SSRI, right? But on one hand, with one hand, they're selling you the SSRI, but with the other hand, and behind your back, they're doing clinical trials with serotonin antagonists that are curing a lot of conditions that are... They must be caused by serotonin because these drugs are selective antagonists on a very specific serotonin receptor. They have no other known mechanism of action. So the only conclusion is that if you elevate extracellular serotonin, you're going to end up with a fibrotic state somewhere. Heart, lungs, kidney, liver, you know, you name it, right?

### Source 9 — EastWest Healing Serotonin and Endotoxin

Ray Peat · Interview · Aug 24, 2011 · http://l-i-g-h-t.com/files/east-west-serotonin-and-endotoxin.mp4

> ## The Role of Serotonin
>
> **Josh Rubin:** I've gotten a lot of requests to talk about serotonin. A lot of people don't know what endotoxin is, but you correlate it with serotonin in the gut. Most people understand serotonin as a brain chemical. Is it a hormone? Where does it come from? Why is there so much focus on serotonin in your research?
>
> **Ray Peat:** You can't understand the other things that I'm working on unless you know where serotonin fits in. For example, estrogen does a lot of its work by way of serotonin. To understand unsaturated fatty acids versus saturated, you have to understand estrogen and serotonin. To understand thyroid, you have to understand all of those. It is one of the emergency defense systems. You can't begin to understand stress or compensating for stress without seeing where serotonin fits in. Hans Selye was one of the early researchers on the biological effects of serotonin, and Aldous Huxley was another person that got me interested in its variety of effects.
>
> **Josh Rubin:** Most Western research refers to serotonin as a brain chemical. Where do you find most of the serotonin in the body, where is it produced, and what are its main functions?

### Source 10 — Gut serotonin (due to bacteria) is the master regulator of metabolism, insulin sensitivity, and weight

Georgi Dinkov · Article · Sep 18, 2019 · https://haidut.me/?p=557

> Over the last year I posted a number of studies demonstrating strong link between serotonin and chronic conditions such as obesity, insulin resistance, and even diabetes.
>
> [references]
>
> However, when those studies came out the medical authorities immediately countered with the argument that it is not serotonin that is the culprit but changes in the microbiome that make the bacteria in our guts less “beneficial”. This statement is untenable in light of the numerous other studies demonstrating that there is no such thing as “beneficial” gut bacteria. Rather, there are only variations of harmfulness and any bacterial overgrowth has strong links to very serious conditions such as cancer, Alzheimer, Parkinson, CVD, etc.
>
> [references]
>
> Now, if the medical industry was simply ignorant, its behavior and claims could be at least understood, if not excused. Yet, behind our backs, Big Pharma has quietly been running clinical trials with drugs that inhibit gut serotonin synthesis as a way of treating obesity, diabetes, osteoporosis, etc.
>
> [references]
>
> It just works so well for the medical/food complex to sell us both the poison (toxic food and drugs) and the remedy (serotonin inhibitors). Well, the study below claims to finally put the questions on the role of serotonin in obesity/diabetes to rest. It demonstrates that sterilizing the guts of mice has the exact same protective effects on their metabolism/weight/health as inhibiting gut serotonin synthesis (with a TPH-1 inhibitor). Administering both the antibiotics and the serotonin synthesis inhibitors did not have additive effects, thus exposing serotonin as the direct pathological agent. As such, there is little doubt that the “happy hormone” is anything but. There is already a mountain of evidence sanctioned by Big Pharma implicating gut bacteria in virtually every psychiatric condition. Now, we can replace the convenient euphemisms such as “microbiome imbalance”, “dysbiosis”, “bacterial overgrowth”, “SIBO”, etc with a single word – SEROTONIN. Aside from estrogen, there is probably no other endogenous mediator of such importance for systemic health, and the sooner the profitable myths about these two chemicals collapse the better for the (literal) survival of humanity. Btw, mainstream media is complicit in this medical disaster by dutifully promoting the medical myths about serotonin that Big Pharma generously sponsors through ads and paid op-ed articles.

### Source 11 — Serotonin (5-HT) may be a major cause of heart valve disease

Georgi Dinkov · Article · May 23, 2026 · https://haidut.me/?p=3033

> Serotonin is almost universally portrayed in the media and by conventional psychiatry as the “happy hormone” — a molecule that lifts mood and is worth boosting with SSRIs (Prozac, Zoloft, etc.). Ray has pointed out for many years that this is a dangerous oversimplification. In reality, 90% of serotonin is produced outside the brain (mostly in the gut), and it acts as a stress hormone, promoting vasoconstriction, platelet aggregation, inflammation, and most importantly — fibrosis. Elevated serotonin has long been known to cause heart valve disease in carcinoid syndrome and in patients taking fenfluramine-phentermine (“Fen-Phen”). The study below now confirms that SSRIs (serotonin reuptake inhibitors) accelerate degenerative mitral regurgitation by increasing serotonin availability.
>
> As the study below demonstrates, researchers analyzed over 9,000 patients who had surgery for degenerative mitral regurgitation (DMR) and found a clear pattern: patients taking SSRIs needed surgery at a significantly younger age than those not on these drugs. The mechanism is straightforward: SSRIs block the serotonin transporter (SERT), leaving more serotonin in circulation and in tissues. In the mitral valve, this excess serotonin stimulates valve cells to produce excess collagen, leading to thickening, stiffening, and eventual failure.
>
> The study also identified a genetic variant (5-HTTLPR “long-long” variant) that reduces SERT activity — essentially mimicking the effect of SSRIs. Patients with this variant were more likely to require surgery, and their valve cells were hyper-responsive to serotonin. Animal models confirmed the causal link: mice lacking the SERT gene developed thickened mitral valves, and normal mice given high-dose SSRIs showed similar changes.
>
> This completely contradicts the mainstream narrative that serotonin is a benign “mood regulator.” Serotonin is a potent pro-fibrotic agent. The heart valve findings are not isolated: follow-up studies showed that low SERT activity also contributes to aortic stenosis (calcification and stiffening of the aortic valve) and myocardial fibrosis. Blocking the serotonin receptor HTR2B reduced these harmful changes, pointing toward a potential therapeutic target.
>
> The human-equivalent dose is not applicable here as this was an observational human study and animal dosing study (SSRI doses in mice are not directly translatable to human depression treatment doses).

### Source 12 — The Character Armor of Pattern Baldness [Audio Article]

Danny Roddy · Video Transcript · Jun 17, 2015 · https://www.youtube.com/watch?v=iYZgwIz7WIk

> In the 2015 paper, Is Serotonin an Upper or Downer?, Andrews et al. suggested that serotonin reuptake inhibitor drugs, or SSRIs, weren't effective and that when they were effective, they worked differently than advertised. Here's a quote from that paper. In summary, we propose that depressed states are high serotonin phenomena, which challenges the prominent role low serotonin hypothesis continues to have in depression research. We also propose the direct serotonin-enhancing effects of antidepressants disturb energy homeostasis and worsen symptoms. We argue that symptom reduction, which only occurs over chronic treatment, is attributable to the compensatory response of the brain attempting to restore energy homeostasis. Serotonin is often considered a brain chemical, however 95% of it is produced in the intestine. Chronic bowel disorders are associated with so-called type D personality, D stands for distress, and elevated levels of serotonin are seen in inflammatory gut diseases such as irritable bowel syndrome, celiac, and Crohn's disease. Serotonin causes inflammation in the intestine and elevated levels of serotonin are a marker for appendicitis. Unsurprisingly, bacterial endotoxin, a constant source of stress in the intestine, increases the release of serotonin. The anti-serotonin drug on Dansetron is helpful for inflammatory bowel problems and can relieve some of the most intrusive symptoms of IBS. Another anti-serotonin drug, ciproheptadine, protects against endotoxin and is probably useful for bowel inflammation. Similar to Ondansetron and Ciproheptadine, LSD appears to antagonize serotonin and might help explain the stereotypical childlike playfulness associated with taking the drug. In the 1950s, acid therapy was effective in the wholesale revamping of one's value system. Oftentimes, those who underwent psychedelic therapy reported dramatic personality changes involving not only relief of neurotic symptoms, but a wholesale revamping of value systems, religious and philosophical beliefs, and basic lifestyle. Raymond Peat was the first person to bring the role of serotonin in inflammation, pain, and depression to my attention. Seemingly light years ahead of the current batch of nutritional personalities, Dr. Peat's research details simple yet effective therapies for reducing serotonin and thus increasing the rate of the metabolism, the generation of carbon dioxide, and the ability to retain a sunny disposition. Taming Serotonin. Number one.

_Generated 2026-07-20 from the Bioenergetic Oracle corpus._