Testosterone was the first successfully synthesized anabolic steroid. Testosterone propionate is a fast-acting, short-ester, oil-based injectable testosterone compound that is commonly prescribed for the treatment of hypogonadism – low testosterone levels and various related symptoms in males.
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.
Cells in the adrenal cortex, ovary, and testis produce endogenous testosterone, the most common androgen in the human body. The treatment of either congenital or acquired hypogonadism involves the use of testosterone. The best exogenous androgen for postmenopausal women to use in the palliative management of breast cancer is testosterone. 1938 saw the introduction of testosterone, which the FDA approved in 1939. Anabolic steroids, which are testosterone derivatives, have been used illegally and are now considered restricted substances. In 1991, testosterone was designated as a restricted substance along with numerous anabolic steroids. Both standard and delayed-release (depot) dose versions of testosterone are supplied parenterally. 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.
The propionate ester is a type of chemical molecule that reacts with water to form alcohols and organic or inorganic acids. The majority of esters are made from carboxylic acids, and one or more esters are frequently supplied along with injectable testosterone. The testosterone molecule has an ester added to it, which affects how soluble it is after it enters the bloodstream. A large/long ester will have a longer half-life; the longer the carbon chain, the longer the ester, and the less soluble the drug. In contrast, short carbon chains, such as the propionate ester, act quickly on the body and expel waste products at a similar rate. The testosterone ester has the shortest half-life of all testosterone esters, at 4 days, thanks to its three-carbon chain.