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, topical creams, and oral forms of testosterone with varying degrees of success. Over time, TRT was improved, refined, and modified to suit the needs of patients. In 1972, the first FDA approved testosterone pellets were introduced, and they offered patients a different option for TRT.(3)

Testosterone pellets are crystalline testosterone implants that are inserted under the skin. Pellets are convenient because the implant procedure, which is conducted in the physician’s office, is typically done only about four times a year since the pellets allow for a gradual, linear release of testosterone over a long period of time. For many men, this “set it and forget it” approach to TRT suits their lifestyle due to busy schedules, aversion to needles, or fear of transference with topical products.

Testosterone pellets are considered to be the most physiologically appropriate form of TRT.(4) Pellets allow for diurnal variations by providing higher testosterone levels during periods of increased activity due to greater blood flow. Because of the many benefits, patients who use testosterone pellets for TRT report higher satisfaction rates than patients using injections or topicals. That being said, pellets aren’t for everyone. With any form of TRT there are pros and cons and patients should research their options and consult with a healthcare professional.

For more information on the benefits of testosterone replacement therapy and to see what therapy may be the best fit for you, check out our presentations on testosterone pellet therapy, TRT for men, and men’s health. You can also contact us at For information on other men’s sexual health issues, visit us at


  1. Freeman ER, Bloom DA, McGuire EJ; A Brief History of Testosterone, J Urol 165:371. 2001
    Hoberman JM, Yesalis CE,; History of Synthetic Testosterone, Sci Am. 1995(Feb)p.76
  2. Hormone Pellet Therapy FAQs; Dr B Rueda, 7/13/2022
  3. Asian J Androl; 2018 Mar-Apr,20(2):195-199, Published online 2017 Dec 5. Doi:10.4103/aja aja 51:17
  4. Clin Endocrin 8/21/1994, JA Cantrill, P Dewis, DM Large