Short answers, pulled from the story.
The Organon group in the Netherlands published a paper titled On Crystalline Male Hormone from Testicles on the 1st of May 1935, marking the isolation of testosterone. This document announced the isolation of testosterone, a substance that would eventually be recognized as the primary architect of male physiology.
Adolf Butenandt and Leopold Ruzicka independently achieved the synthesis of testosterone from cholesterol in August 1934. Their work earned them the joint 1939 Nobel Prize in Chemistry, cementing testosterone's place as a cornerstone of endocrinology.
Over 95 percent of testosterone is produced by the testes in men, while the adrenal glands account for most of the remainder. In women, testosterone is synthesized in far smaller total quantities by the adrenal glands, thecal cells of the ovaries, and the placenta during pregnancy.
Testosterone does not create aggression in an individual but amplifies aggressive behaviors and responses that are already learned by the individual, increasing sensitivity to social triggers rather than inventing violence. Studies have found that testosterone facilitates aggression by modulating vasopressin receptors in the hypothalamus, but the relationship between testosterone and aggression is complex and context-dependent.
The first clinical trials of testosterone replacement therapy were conducted on the 1st of January 1936. This was a time when the medical community was just beginning to understand the potential of testosterone as a treatment for various conditions, including male hypogonadism, gender dysphoria, and certain types of breast cancer.