Ray Peat on Progesterone

Short answer: Progesterone was Ray Peat's original research subject. He described it as the main protective hormone: it opposes estrogen and cortisol, protects the brain, heart and pregnancy, and falls when thyroid function and nutrition are poor.

What Ray Peat wrote about progesterone

He called progesterone both anticatabolic and antiestrogenic. In both roles it protects working tissues from wasting. Source: Aging, estrogen, and progesterone

He described it as a nerve growth factor made in the brain. It promotes myelin, protects against seizures and free radicals, and with pregnenolone it shields nerve cells from excitotoxic damage. Source: Alzheimer's: The problem of Alzheimer's disease as a clue to immortality — part 2, Multiple Sclerosis and other hormone related brain syndromes, Estrogen — Age Stress Hormone

In cancer research going back to the 1930s, he wrote, estrogen was shown to be carcinogenic and progesterone protective, in primates as well as rodents. Source: Preventing and treating cancer with progesterone

He argued that progesterone, not estrogen, is what protects women's hearts. Source: Progesterone, not estrogen, is the coronary protection factor of women

It restrains the stress system by inhibiting the ACTH response and limiting the harmful actions of cortisol. Source: Preventing and treating cancer with progesterone

Progesterone raises body temperature and metabolic rate, the opposite of estrogen. Source: Multiple sclerosis, protein, fats, and progesterone, Hot flashes, energy, and aging

He explained why studies sometimes find harm: the hormone was often dissolved in toxic vehicles such as vegetable oil, so the experiment tested the oil. Source: Estrogen, progesterone, and cancer: Conflicts of interest in regulation and product promotion, Progesterone Deceptions

His own solution was to dissolve progesterone in vitamin E, which is absorbed through the skin and the gut. Source: Progesterone Deceptions

What he suggested in practice

• He treated thyroid, protein and light as the conditions that let the body make its own progesterone.
• For topical use he describes progesterone dissolved in vitamin E, applied after a little olive oil.
• Progesterone is a hormone. Use it with a doctor.

Where he wrote about it

This topic comes up in 85 of the articles on his site. These are the most relevant ones:

• Estrogen, progesterone, and cancer: Conflicts of interest in regulation and product promotion · original on raypeat.com ↗
• Preventing and treating cancer with progesterone · original on raypeat.com ↗
• RU486, Cancer, Estrogen, and Progesterone · original on raypeat.com ↗
• Tissue-bound estrogen in aging · original on raypeat.com ↗
• Progesterone Summaries ↗ · original on raypeat.com ↗
• Progesterone Deceptions · original on raypeat.com ↗
• The dark side of stress (learned helplessness) · original on raypeat.com ↗
• Epilepsy and Progesterone · original on raypeat.com ↗

Quick answers

What did Ray Peat say about progesterone?

That it is the body's main protective hormone, opposing estrogen and cortisol and protecting the brain, heart, bones and pregnancy.

Why did Ray Peat dissolve progesterone in vitamin E?

Because progesterone is fat-soluble and poorly absorbed in other forms. Dissolved in vitamin E it is absorbed through the skin and the intestine.