Progesterone is recognized as the oldest hormone known to humanity, succeeded by Vitamin D3 (cholecalciferol). While classified as a vitamin, Vitamin D3 undergoes conversion in the liver to calcidiol, which is subsequently transformed by the kidneys and other tissues into calcitriol, a powerful steroid hormone.

The history of progesterone spans roughly 500 million years, marking its established timeline of existence. However, the 2010 discovery of this hormone within the molecules of the walnut tree indicates that its origin could be even older. Researchers propose that progesterone may serve as an ancient bio-regulator that evolved billions of years ago, predating the emergence of plants and animals. This newfound evidence has the potential to reshape scientific perspectives on the evolution and role of progesterone in living organisms.

The following plants and more, contain Phytosterols:

Soy Bean

Dioscorea ~ Species of Yams

Fenugreek

Sisal

Calabar Bean

Various Lilies

Yucca

Some Solanum Species

Maize

Some of these are:

Stigmasterol

Diosgenin

Sitosterol

Campesterol

Hecogenin

Sarsasapogenin

Salasodine

A great deal of confusion exists regarding the production and origin of progesterone. This uncertainty stems from various websites and blogs that disseminate misleading information; some claim it is derived from yam, while others assert it comes from soy.

As previously mentioned, progesterone is synthesized from a variety of plant sterols, often referred to as phytosterols. All plants contain these sterols, including sources like soybean, Dioscorea species of yams, fenugreek, sisal, Calabar bean, certain lilies, yucca, various solanum species, maize, and many others. Notable phytosterols include stigmasterol, diosgenin, beta-sitosterol, campesterol, hecogenin, sarsasapogenin, and solasodine. Due to their structural similarity to cholesterol, these plant sterols serve as precursors in the synthesis of progesterone. The final product is solely progesterone, with no other substances present. If contaminated with anything else, whether from yam, soy, or any other plant, it could not be legally classified as progesterone. Ultimately, it does not matter which plant is utilized for synthesizing progesterone; the end result is progesterone, plain and simple.

It was only in 1933 that the pure hormone was isolated and later named progesterone. An article called “Recollections of my Life with Progesterone by Willard Allen recounted the discovery and isolation in 1974.

Progesterone, an unfortunate name in that it is now known as a female hormone, but also a sex hormone. Because of this, many other roles have been overlooked sadly.

Progesterone is NOT a sex hormone, it plays no part in the secondary sexual characteristics which develop at puberty, which are governed by estrogen in females and testosterone in males. There are no differences between men and women other than the luteal phase. Progesterone is secreted primarily by the ovaries in females and the testes in males. Small amounts are produced by the adrenal glands, the brain and the glial cells. It is the precursor to the sex hormones estrogen and testosterone, as well as the adrenal hormones, cortisol and aldosterone.

In 1929 Adolf Butenandt Ph.D isolated estrone, one of a group of steroids known collectively as estrogen. Edward Doisy, discovered estrone. In 1931 Adolf Butenandt isolated aldosterone at the same time confirming the existence of yet another estrogen called estriol. This had been discovered earlier by G F Merrian but was never confirmed.

In 1933, for the first time, the similarity between the molecular structures of androsterone and cholesterol were found. In 1934 Adolf Butenandt isolated a small sample of progesterone from the corpus luteum, corresponding with Willard Allen about their independent discovery.

In 1935 Ernst Laqueur isolated testosterone from the testes. Shortly after, both Adolf Butenandt and Leopold Ruzicka synthesised testosterone from androsterone. They were both awarded the Nobel Prize for Chemistry in 1939.

Around the same time, Percy Julian Ph.D extracted stigmasterol from the West African Calabar bean or Physostigma Venenosum. He was an amazing chemist who was awarded 130 patents and many honorary degrees. He is best known for his work in the industrial synthesis of human steroids from plant sterols. His work later led to the production of cortisone. He isolated stigmasterol from soybean oil in 1939. By 1940 he was able to produce the hormone progesterone in bulk.

In 1936 Russell Market isolated the steroid pregnanediol from an extract of pregnant mares urine. He converted this to progesterone in 1937. In 1938 he found the sterol sarsasapogenin from the sarsaparilla plant, could be converted into progesterone using a technique which has since become known as the Market Degradation. However, sarsaparilla was expensive so he continued searching and found the sterol diosgenin in 1941. The diosgenin in the Dioscorea species of a yam growing wild in Mexico which could also be converted into progesterone. Sadly no pharmaceutical company was interested in his discovery. So, in 1943 he used a friend’s lab and converted the diosgenin into three kilograms of progesterone. In 1944 he formed Syntex in Mexico City with two partners, a company which competed with Percy Julian’s soybean progesterone.

Because of the low cost of Russell Market’s progesterone, it later became the preferred precursor to cortisone and by 1951 Syntex had developed the first oral contraceptive from progesterone.