The concept of testosterone replacement therapy (TRT) dates back to the early 1900s. Observations of behavioral changes in castrated roosters formed the foundation of what we know to be hypogonadism or “low T.” The concept of “treat like with like” spurred research and by the mid 1930s, testosterone synthesis began. (1)
During the 1930s, we saw the initiation of TRT with testosterone propionate injections as well as subcutaneous testosterone pellets.(2) By the mid 1940s, researchers had identified multiple indicators of low testosterone including depression, failing memory, increased fatigability, and reduced libido. We now apply that early research, with improved understanding of physiology and the aging process, to successfully treat millions of men who experience the unwanted effects of low testosterone.
For years, men were prescribed testosterone injections,