Testosterone propionate was first described in 1935 to increase synthetic testosterone’s therapeutic usefulness by slowing its release into the bloodstream. It was released for clinical use two years later by Schering AG in Germany, featured in a hybrid blend with testosterone enanthate under the brand name Testoviron. This was also the first commercially available version on the U.S. prescription drug market and remained the dominant form of testosterone globally prior to 1960.
Testosterone is the primary androgen found in the body. Endogenous testosterone is synthesized by cells in the testis, ovary, and adrenal cortex. Therapeutically, testosterone is used in the management of hypogonadism, either congenital or acquired. Testosterone is also the most effective exogenous androgen for the palliative treatment of carcinoma of the breast in postmenopausal women. Testosterone was in use in 1938 and approved by the FDA in 1939. Anabolic steroids, derivatives of testosterone, have been used illicitly and are now controlled substances. Testosterone, like many anabolic steroids, was classified as a controlled substance in 1991. Testosterone is administered parenterally in regular and delayed-release (depot) dosage forms. In September 1995, the FDA initially approved testosterone transdermal patches (Androderm); many transdermal forms and brands are now available including implants, gels, and topical solutions. A testosterone buccal system, Striant, was FDA approved in July 2003; the system is a mucoadhesive product that adheres to the buccal mucosa and provides a controlled and sustained release of testosterone. In May 2014, the FDA approved an intranasal gel formulation (Natesto). A transdermal patch (Intrinsa) for hormone replacement in women is under investigation; the daily dosages used in women are much lower than for products used in males. The FDA ruled in late 2004 that it would delay the approval of Intrinsa women’s testosterone patch and has required more data regarding safety, especially in relation to cardiovascular and breast health.