# Progesterone

Category: Hormones

Progesterone is the main female hormone, and is a protective hormone during pregnancy, but it is also important in men since it is a general brain regulating and protective hormone.

9 passages · 1 author · 1992–2022 · Most-cited: [Ray Peat](https://bioenergeticoracle.com/md/voices/ray-peat/index.md)

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

## Synthesis

**Progesterone** is the most protective hormone the body produces, functioning as a fundamental stabilizer of cellular energy and structure rather than merely a sex steroid. [Source 8] Ray Peat classified it as a *non-hormonal steroid* because it stabilizes energy and structural systems instead of causing excitation, and he identified it as the most powerful **anti-chaotropic** (order-preserving) substance on the cellular level. [Source 5, 9] This intrinsic property explains its remarkably broad spectrum of protective actions, from anti-toxic and anti-stress effects to the regulation of cellular excitation thresholds in nerves, smooth muscle, and cardiac muscle. [Source 5] The brain normally contains about ten times the concentration of progesterone found in blood serum, reflecting its critical role in protecting that organ, and the skin is a major contributor to the body's progesterone background. [Source 4]

Progesterone's biological generality operates through three distinct mechanisms. First, it possesses intrinsic hormonal activities that overlap with all other steroid functions except those of estrogen and testosterone, including **lysosome stabilization**, salt regulation, blood sugar elevation, and nerve modulation. [Source 2] Second, it serves as the direct precursor for all other steroid hormones, allowing the body to produce an appropriate and balanced amount of them when supplied as a raw material. [Source 2] Third, it acts as a comprehensive antagonist to estrogen, opposing its broad physiological effects in both males and females. [Source 2] Peat demonstrated that progesterone acts directly on mitochondria to promote energy production and facilitates thyroid hormone function, while also promoting the elimination of estrogen from tissues. [Source 1] The mitochondrial progesterone receptor is, in effect, the *mitochondrion function itself*, which explains why progesterone's actions are always protective and anti-inflammatory without exception. [Source 6]

Progesterone's therapeutic applications span a wide range of conditions rooted in inflammation and cellular disorganization. It has been used effectively to treat epilepsy, habitual miscarriages, autoimmune diseases, and cancer of the uterus, breast, and kidney. [Source 5] It restores normal tone to smooth muscles including the gall bladder, urinary bladder, intestine, sphincters, and uterus, and normalizes fluid pressure in conditions such as bursitis and glaucoma. [Source 5] In the circulatory system, it prevents venous pooling of blood, maintains normal filling of the heart, and opposes shock, with immediate improvements in circulation that can restore kidney function and heal gangrenous toes. [Source 5] Progesterone is also essential for nerve cell growth and survival, and its deficiency leads to destabilized nerve function and increased **luteinizing hormone**, which itself has toxic, pro-inflammatory effects. [Source 4, 5]

The development of a vitamin E-based delivery system around 1980 dramatically improved progesterone's clinical utility. Peat discovered that vitamin E, with its crucial effect on mitochondrial respiratory enzymes, is a uniquely powerful, stable, and biologically compatible solvent for progesterone. [Source 5] This solution, when taken orally, is absorbed with nearly 100% efficiency through a natural digestive route that distributes it to all tissues, allowing it to escape the liver's tendency to rapidly convert progesterone to an excretory form. [Source 7] This contrasts sharply with other delivery methods: less than 5% absorption is typical from suppositories, and injectable forms using benzyl alcohol and vegetable oil cause progesterone to crystallize out of solution upon contact with tissue fluid. [Source 7] The vitamin E solvent permits otherwise impossibly high doses, increasing progesterone's dramatic effects by as much as 2000-fold in major biological problems. [Source 5]

Progesterone's anti-cancer properties stem from its fundamental opposition to estrogen-driven processes. Estrogen causes mutations and genetic instability, while progesterone does not harm genes. [Source 3] Progesterone stops cellular proliferation and promotes differentiation by keeping the **retinoblastoma protein** in its unphosphorylated, active protective state, an effect that is reciprocal to estrogen's action on that same protein. [Source 3] While synthetic progestins often imitate estrogen and increase cellular proliferation, natural progesterone causes only two cell divisions before ending with cell differentiation. [Source 3] Peat emphasized that progesterone is not merely a pregnancy hormone; it is the most basic anti-cancer agent for progesterone-related cancers, and its deficiency has been associated with increased susceptibility to cancer in general. [Source 6, 8]

## People also ask

### How does progesterone stabilize cells beyond its role as a sex hormone?

Peat classified progesterone as a non-hormonal steroid because it acts as a fundamental anti-chaotropic agent that preserves cellular order, stabilizes energy systems, and regulates excitation thresholds in nerves and muscles rather than causing stimulation.

### Why is vitamin E used as a solvent for progesterone supplements?

Peat discovered that vitamin E is a uniquely powerful and biologically compatible solvent that allows nearly 100% oral absorption by bypassing rapid liver excretion, increasing progesterone's therapeutic effects by up to 2000-fold compared to other delivery methods.

### How does natural progesterone differ from synthetic progestins in cancer risk?

The corpus describes that natural progesterone stops cell proliferation and promotes differentiation by keeping the retinoblastoma protein active, whereas synthetic progestins often imitate estrogen and increase cellular proliferation.

## Related concepts

- [Albumin](https://bioenergeticoracle.com/md/concepts/albumin/index.md)
- [Anemia](https://bioenergeticoracle.com/md/concepts/anemia/index.md)
- [Dehydroepiandrosterone (DHEA)](https://bioenergeticoracle.com/md/concepts/dehydroepiandrosterone-dhea/index.md)
- [Estrogen](https://bioenergeticoracle.com/md/concepts/estrogen/index.md)
- [Melatonin](https://bioenergeticoracle.com/md/concepts/melatonin/index.md)
- [Pituitary Gland](https://bioenergeticoracle.com/md/concepts/pituitary-gland/index.md)

## Cited passages

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

### Source 1 — Glossary

Ray Peat · Glossary

> Progesterone
>
> Progesterone is the main female hormone, and is a protective hormone during pregnancy, but it is also important in men since it is a general brain regulating and protective hormone.
>
> Progesterone, because of its normal anesthetic function (which prevents the pain of childbirth when its level is adequate), directly quiets nerves, and in this way suppresses many of the excitotoxic processes. It has direct effects on mitochondria, promoting energy production, and it facilitates thyroid hormone functions in various ways. It promotes the elimination of estrogen from tissues, and is a "diuretic" in several benign ways, that are compatible with maintenance of blood volume.
>
> Progesterone is an anti-androgen and blocks testosterone's effects.

### Source 2 — From PMS to Menopause: Female Hormones in Context

Ray Peat · Book · 1997

> **Ray Peat:** Pregnenolone (produced from cholesterol in the mitochondria), which is the precursor to progesterone and other steroids, has been used successfully to restore fertility (sperm count and motility, and, according to the wives--libido) in men. All of the natural steroids have functions that overlap to some extent--e.g., testosterone has some progestational function--but progesterone's generality is the most remarkable. 2. Steroid precursor function. The second aspect of progesterone's biological generality, besides its intrinsic hormonal activity, is its role as precursor for all of the other steroid hormones (see chart). When consumed in food (e.g., butter, brains, milk, ovaries--some cultures eat pork ovaries, many eat sea-urchin ovaries), it, like cholesterol, only more efficiently, enters the cycle of steroid synthesis near the beginning, so that it is a raw material, allowing normal amounts of the other hormones to be produced. This aspect of progesterone distinguishes it most strongly from the other progestins (e.g., medroxyprogesterone), which have had atoms introduced at unusual positions to inhibit metabolism and prolong activity (as well as to create a patentable and thus highly profitable substance). When we eat protein, we support the production of all the peptide hormones; likewise, natural progesterone (and pregnenolone, which is also found in brains, endocrine glands, and probably skin) serves to allow the body to produce an appropriate and balanced amount of all the other steroid hormones. 3. Anti-estrogen functions. A third aspect of progesterone's generality is a little less clear than its intrinsic generality and its function as a general steroid precursor, because this third form has to do with its overall antagonism to estrogen, and gains significance only to the extent that we see estrogen as having a very broad physiological role--for males as well as for females.

### Source 3 — RU486, cancer, estrogen, and progesterone.

Ray Peat · Article · 2007 · https://raypeat.com/articles/articles/ru486.shtml

> Progesterone is anti-inflammatory, and reduces cellular excitation.
>
> Even within their small world of molecular endocrinology, thinking in ways that have been fostered by computer technology, about gene networks, interacting nodes, and crosstalk between pathways, their model and their arguments don't work.
>
> They have left out the complexity that could give their argument some weight.
>
> The medical mainstream has recognized for 30 years that progesterone protects the uterus against cancer; that was the reason for adding Provera to the standard menopausal hormonal treatment.
>
> The new claim that natural progesterone causes breast cancer should oblige them to explain why the hormone would have opposite effects in different organs, but the mechanisms of action of estrogen and progesterone are remarkably similar in both organs, even when examined at the molecular level.
>
> If "molecular endocrinologists" are going to have interpretations diametrically opposed to classical endocrinology (if black is to be white, if apples are to fall up), they will have to produce some very interesting evidence.
>
> Cancer is a malignant (destructive, invasive) tumor that kills the organism.
>
> The main dogma regarding its nature and origin is that it differs genetically from the host, as a result of mutations.
>
> Estrogen causes mutations and other forms of genetic instability, as well as cancer itself.
>
> Progesterone doesn't harm genes or cause genetic instability.
>
> The speculative anti-progesterone school has put great emphasis on the issue of cellular proliferation, with the reasoning that proliferating cells are more likely to undergo genetic changes.
>
> And synthetic progestins often do imitate estrogen and increase cellular proliferation.
>
> People like the Lees are asserting as an established fact that progesterone increases cellular proliferation.
>
> A paper by Soderqvist has been cited as proof that progesterone increases the proliferation of breast cells.
>
> He saw more mitoses in the breasts during the luteal phase of the menstrual cycle, and said the slightly increased mitotic rate was "associated with" progesterone.
>
> Of course, estrogen increased at the same time, and estrogen causes sustained proliferation of breast cells, while progesterone stimulation causes only two cell divisions, ending with the differentiation of the cell.

### Source 4 — One Radio Network: Ray Peat with Patrick Timpone — June 21, 2021

Ray Peat · Interview · Jun 21, 2021

> **Ray Peat:** the um progesterone is a protective substance. I don't even think of it as a hormone. It is so basic in the way it protects cells. And it's greatly increased during pregnancy because the developing fetus needs special protections. But the average person, male or female, has a very high concentration of progesterone in the brain because the brain needs special protection. And normally the brain contains about 10 times as much progesterone as in the blood serum. The brain produces progesterone. All of our tissues can produce some, but it's helpful if you have a placenta or ovary corpus luteum that is specialized in producing it but if you're in good health your brain is able to produce a lot of it your skin is a major contributor to your progesterone background and when you're low in progesterone the luteinizing hormone a pituitary gonadotropin increases and it happens that if the luteinizing hormone is too high it in itself has toxic effects and keeping the luteinizing hormone in a moderate low range is good for the health simply because the pituitary hormones themselves function as pro-inflammatory irritants and so Since progesterone, along with testosterone, tends to lower your luteinizing hormone, that's part of its benefit. When progesterone falls at menopause, the high luteinizing hormone attempting to make the ovaries produce more becomes toxic in itself. and contributes to many of the symptoms of menopause. It's the same with a man. If your brain is deficient in cholesterol or thyroid or vitamin A, all of which are needed to synthesize progesterone locally in the skin or in the brain, then you'll experience the effects. not only of the progesterone deficiency destabilizing your nerve function, but also increased luteinizing hormone and its toxic effects.

### Source 5 — Origins of Progesterone Therapy

Ray Peat · Newsletter · Nov 1992

> In the mid-1970s, I found that progesterone is the most powerful order-preserving substance (anti-chaotropic) on the cellular level, and that this explains its range of protective actions, from anti-toxic to anti-stress.
>
> Around 1980, I discovered that vitamin E, with its crucial effect on the mitochondrial respiratory enzymes, is a uniquely powerful, stable, and biologically compatible solvent for progesterone.
>
> Their intimate association at certain cellular sites requires mutual solubility. This property of mutual affinity extends to all biological areas, meaning that the solution of progesterone in vitamin E can be administered with exceptional efficiency by application to the skin or other membranes, or by ingestion, where normal digestive processes convert it into chylomicrons and distribute it to all tissues, allowing it to escape the tendency of the liver to convert it rapidly to an excretory form, as occurs when progesterone is administered in other forms.
>
> Because of its profound biological compatibility, the progesterone-vitamin E solution permits otherwise impossibly high doses to be given, increasing by as much as 2000 progesterone's already dramatic effects in a wide range of major biological problems, including epilepsy, habitual miscarriages, auto-immune diseases, and cancer of the uterus, breast, and kidney.
>
> ## Some Aspects of Basic Progesterone Research
>
> By 1945, Hans Selye had demonstrated that progesterone in itself has the full spectrum of regulatory and anti-stress functions of the adrenal steroids.
>
> A little later, Albert Szent-Györgyi showed that progesterone is able to regulate the heart, in a manner similar to digitalis. In the 1970s, I demonstrated that it acts similarly on vascular smooth muscle, regulating its tone and preventing venous pooling of blood, and maintaining normal filling of the heart, opposing shock. The immediate improvement in circulation can have dramatic effects, which include restoration of kidney function, elimination of fluid from the lungs, restoration of sensation in the feet, and healing of gangrenous toes.
>
> It restores normal tone to other smooth muscles, including the gall bladder, urinary bladder, intestine, sphincters, and uterus.
>
> Progesterone's ability to regulate thresholds of cellular excitation operates in nerves, as well as in smooth and cardiac muscle. It sensitizes nerves that regulate respiration, and has been used to treat infant apnea, sleep apnea in adults, and polycythemia vera in men.

### Source 6 — One Radio Network: Ray Peat with Patrick Timpone — July 18, 2022

Ray Peat · Interview · Jul 18, 2022

> **Ray Peat:** I think progesterone is the most basic anti-cancer agent for progesterone-related cancers. Originally, everyone wanted to find the progesterone receptor what is really causing the action of progesterone but they couldn't find that in most tissues or they couldn't identify what it might really be doing but suddenly they stopped assuming there should be specific progesterone receptors for every function, because empirically they saw that progesterone had general functions that always seemed to be in the same line, always protective, always anti-inflammatory. And finally it occurred to someone, maybe they're looking for the wrong thing in the case of progesterone. How can it have two or three different receptors supposedly having different actions if they're all going to act in the same direction. And so when they stopped looking for a specific pair of actions that never showed up, they saw that there was a generalized action without exception, cells became responsive to progesterone. So they had been creating an illusion that there was this mysterious, why did both kinds of progesterone function? Why did they have such a similar actions. It turns out that when you look for it, it's the mitochondrial melanin senses so-called progesterone receptor. But it's really the energy producing property of the mitochondrial substance. The mitochondrial progesterone receptor is, in effect, the mitochondrion function itself.

### Source 7 — Origins of Progesterone Therapy

Ray Peat · Newsletter · Nov 1992

> Progesterone's ability to regulate thresholds of cellular excitation operates in nerves, as well as in smooth and cardiac muscle. It sensitizes nerves that regulate respiration, and has been used to treat infant apnea, sleep apnea in adults, and polycythemia vera in men.
>
> In cases of specific progesterone deficiency in men, small doses can cure impotence. It has been used effectively to treat benign prostatic enlargement.
>
> It normalizes fluid pressure, as in bursitis and glaucoma treatment.
>
> It restores many of the functions of aged skin, and is the normal defense against calcium loss from bones.
>
> It is one of the few essential requirements, besides nutrients, for nerve (brain) cell growth and survival. In young people of both sexes, the brain contains more progesterone than other organs do.
>
> It is reasonable that progesterone, the dominant hormone in pregnancy, should have a full range of protective functions to protect the vulnerable organism during its intra-uterine life.
>
> ## Practical Issues
>
> A typical dose of progesterone/vitamin E, 20day for 10 consecutive days, costs about $1.00 per month, at the present retail price.
>
> Pharmacists have the authority to compound drugs as they choose, just as physicians can prescribe the formulation they prefer.
>
> Neither progesterone nor vitamin E has any toxicity when used orally.
>
> Under federal law, a prescription is needed for a dosage form of a drug that is potentially harmful. In practice, the very dangerous injectable insulin is always sold without need for a prescription, presumably because its use is conceived as akin to nutrition, providing an essential natural substance to restore a natural function of the body. By analogy with insulin, the infinitely less dangerous progesterone should not require a prescription.
>
> The logical way to make progesterone/vitamin E available to the public would be to license the patent to a chain of drugstores.
>
> The availability of this effective and economical form of progesterone can hardly be kept secret, because people tell their friends, and patients eventually convince their physicians that it works.
>
> An exclusive licensing agreement would be possible with 10 royalties, based on the retail price, with a guaranteed sales volume, and with lower royalties for larger volumes.
>
> ## Economic Questions
>
> Because of its absorption by a natural digestive route which distributes it to all of the tissues, progesterone dissolved in vitamin E is almost 100 absorbed when taken orally.

### Source 8 — From PMS to Menopause: Female Hormones in Context

Ray Peat · Book · 1997

> ### 10. YOUTH ASSOCIATED HORMONES
> #### PROGESTERONE
>
> **Ray Peat:** Sixty years ago, progesterone was found to be the main hormone produced by the ovaries. Since it was necessary for fertility and for maintaining a healthy pregnancy, it was called the "pro-gestational hormone," and its name sometimes leads people to think that it isn't needed when you don't want to get pregnant. In fact, it is the most protective hormone the body produces, and the large amounts that are produced during pregnancy result from the developing baby's need for protection from the stressful environment. Normally, the brain contains a very high concentration of progesterone, reflecting its protective function for. that most important organ. The thymus gland, the key organ of our immune system, is also profoundly dependent on progesterone. In experiments, progesterone was found to be the basic hormone of adaptation and of resistance to stress. The adrenal glands use it to produce their anti-stress hormones, and when there is enough progesterone, they don't have to produce the potentially harmful cortisone. In a progesterone deficiency, we produce too much cortisone, and excessive cortisone causes osteoporosis, aging of the skin, damage to brain cells, and the accumulation of fat, especially on the back and abdomen. Experiments have shown that progesterone relieves anxiety, improves memory, protects brain cells, and even prevents epileptic seizures. It promotes respiration, and has been used to correct emphysema. In the circulatory system, it prevents bulging veins by increasing the tone of blood vessels, and improves the efficiency of the heart. It reverses many of the signs of aging in the skin, and promotes healthy bone growth. It can relieve many types of arthritis, and helps a variety of immunological problems. If progesterone is taken dissolved in vitamin E, it is absorbed very efficiently, and distributed quickly to all of the tissues.

### Source 9 — #51: Heat Shock Proteins  |  Antibiotic Resistance  |  DHT Safety  |  Energy and Aging with Ray Peat, PhD

Ray Peat · Interview · Mar 4, 2021

> ## Progesterone and Progest-E
>
> **Danny Roddy:** I want to talk about Progest-E. Ray, you've mentioned you are confident in this product.
>
> **Ray Peat:** I've used it for 45 years. I experimented with safe and effective solvents and came up with the Progest-E complex formula in the 1970s. I tried it on a roommate's pet rabbit that had a brain tumor and couldn't hop or stand. I rubbed the oily solution on the skin inside its ears. It went into a deep sleep, and hours later, it leaped to its feet like a new rabbit. It hopped to a wall and urinated copiously, unloading a large amount of water that had been causing swelling and pressure.
>
> **Georgi Dinkov:** Why would progesterone fill in for the adrenal glands but pregnenolone wouldn't? Selye's experiments showed pregnenolone wasn't as effective for survival in adrenalectomized rats.
>
> **Ray Peat:** Selye showed that each steroid has a range of properties. Progesterone will fill in for a deficiency of aldosterone, cortisol, or androgen, but it will also protect against a toxic dose of those same things because it has a weak mineralocorticoid effect. I classify progesterone as a non-hormonal steroid because it stabilizes the energy and structural systems rather than causing excitation.

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