History of Testosterone in Timeline

By Popular Timelines Editorial Team · Updated: July 15, 2026

Testosterone is a primary androgenic hormone produced predominantly in the testes in males and, to a lesser extent, in the ovaries and adrenal glands in females. As a steroid hormone derived from cholesterol, it plays a critical role in the development of male reproductive tissues such as the prostate and testes. Beyond reproduction, testosterone is essential for promoting secondary sexual characteristics, including increased muscle mass, bone density, and body hair growth. It also significantly influences metabolic function, mood, and libido. Regulation occurs via the hypothalamic-pituitary-gonadal axis, where the brain monitors and adjusts production levels to maintain homeostasis. While primarily associated with masculine traits, balanced levels are vital for the physiological well-being of all genders. Fluctuations or deficiencies can lead to various clinical issues, including hypogonadism, muscle atrophy, and changes in cognitive or emotional health, often requiring medical intervention through hormone replacement therapy.

1927: Initial Extraction of Masculinizing Substance

In 1927, Professor Fred C. Koch and student Lemuel McGee at the University of Chicago successfully extracted 20 mg of a biological substance from 40 pounds of bovine testicles. They demonstrated that this isolate could effectively re-masculinize castrated roosters, pigs, and rats.

1934: Purification of Testosterone at University of Amsterdam

In 1934, Ernst Laqueur's research group at the University of Amsterdam achieved the purification of testosterone from bovine testicles. This development set the stage for later full-scale industrial research into steroid hormones by major pharmaceutical companies.

May 1935: First Isolation of Testosterone

In May 1935, the Organon group in the Netherlands successfully isolated the hormone testosterone, a milestone they documented in their paper titled "On Crystalline Male Hormone from Testicles (Testosterone)." The researchers coined the name by combining the terms testicle, sterol, and ketone.

1936: Demonstration of Testosterone's Nitrogen-Retaining Effects

In 1936, researchers Kochakian and Murlin successfully demonstrated that the hormone testosterone facilitates nitrogen retention in dogs, a pivotal finding that established the fundamental mechanism behind its anabolic properties.

1939: Nobel Prize in Chemistry awarded for Testosterone synthesis

In 1939, Adolf Butenandt and Leopold Ruzicka were jointly awarded the Nobel Prize in Chemistry in recognition of their independent achievements in the partial synthesis of testosterone using cholesterol as a base.

1976: Passing of Leopold Ruzicka

Leopold Ruzicka (1887–1976), a chemist noted for his work on the synthesis of testosterone at the Ciba group in Zurich, passed away in 1976.

2020: American College of Physicians Testosterone Guidelines

In 2020, the American College of Physicians issued guidelines supporting testosterone treatment for adult men with age-related low levels who experience sexual dysfunction. The guidelines advise a yearly evaluation to determine if treatment should continue and suggest that intramuscular administration is preferable to transdermal methods due to cost, as clinical efficacy and harm profiles are comparable. Additionally, the guidelines emphasize that testosterone therapy is generally not recommended for purposes outside of addressing sexual dysfunction, and stress the necessity of thorough baseline and ongoing health monitoring.