Testosterone Propionate

Testosterone propionate, which used to be available under the brand name Testoviron, is an injectable form of testosterone no longer found in the United States. It’s still available in other countries including Abu Dhabi, Australia, Belgium, Hong Kong, Latvia, New Zealand, Saudi Arabia, and the United Kingdom (Yoon, 2019).

Testosterone propionate fell out of favor when longer-acting forms of testosterone hit the market. These longer-acting products (like testosterone enanthate, testosterone cypionate, and testosterone undecanoate) require fewer doses and have better safety profiles. Today, they are the mainstays of TRT (Petering, 2017).

Testosterone Propionate

The biggest problem with testosterone propionate is its short half-life. The half-life of a drug is a pharmacology measurement of how long it takes your body to get rid of it. The longer the half-life, the longer a medicine can stick around and do its job. Because of its short half-life, you’d need to take several injections intramuscularly every week to reach an adequate level of testosterone (Rey, 2020).  

While the manufacturer discontinued the drug, it wasn’t because of safety or efficacy reasons––likely it was because there were better options available (Yoon, 2019).

Even though testosterone propionate is not prescribed as a medication anymore, it’s often used in scientific experiments that need a quick-acting hormone (Park, 2019).

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.

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.

The Propionate Ester: An ester is any of a class of organic compounds that react with water to produce alcohols and organic or inorganic acids. Most esters are derived from carboxylic acids, and injectable testosterone is typically administered along with one or multiple esters. The addition of a carbon chain (ester) attached to the testosterone molecule controls how soluble it will be once it’s inside the bloodstream. The larger the carbon chain, the longer the ester, and the less soluble the medication; a large/long ester will have a longer half-life. The inverse is true of short carbon chains, like the propionate ester, which acts rapidly upon the body and evacuates the body at a similar rate. With a three-carbon chain, the testosterone ester possesses the shortest half life of all testosterone esters at 4 days.

Why is testosterone so important?

Why is testosterone so important

Testosterone is a male sex hormone (or androgen) that plays a role in sexual health and the development of male characteristics during puberty. 

Testosterone plays a vital role in health throughout our entire lives. Low levels of this hormone may cause the following symptoms (Sizar, 2021):

  • Sexual issues like loss of libido (sex drive) or erectile dysfunction
  • Mood disorders including depression and anxiety
  • Loss of bone mineral density
  • Changes in red blood cells
  • Changes in muscle mass and body fat composition
  • Fertility issues

Other forms of testosterone

Testosterone propionate is no longer used in healthcare, but several newer derivatives of testosterone have replaced it. Some other types of TRT available include (Petering, 2017):

  • Testosterone cypionate (brand name Depo-Testosterone), intramuscular injection
  • Testosterone undecanoate (brand name Jatenzo), taken by mouth
  • Testosterone enanthate (brand name Delatestryl), taken by injection
  • Testosterone nasal gel (brand name Natesto), applied to the nose
  • Testosterone topical gel (brand names Androgel, Fortesta, and Testim), applied to the skin
  • Testosterone patch (brand name AndroDerm), applied to the skin (DailyMed, 2020)

Each testosterone formulation comes with different directions, so make sure to take the dose prescribed by your healthcare provider. All forms of testosterone for TRT require a prescription from your healthcare provider.

Uses for testosterone replacement therapy

Testosterone replacement therapy can be helpful for treating conditions like hypogonadism (low T), gender dysphoria, and androgen deficiencies (Petering, 2017):

As we mentioned, testosterone is known for its “androgenic” properties in men like developing body hair and maintaining a sex drive. But it has involvement in many bodily functions in both men and women. 

Testosterone plays a role in the strength of your bones and the way you process cholesterol. Testosterone is also related to how your body forms fat. Interestingly enough, it can be found at lower levels in people who are overweight or obese (Nassar, 2021). 

Clinical trial participants who took T showed a significant benefit in symptoms associated with hypogonadism (Snyder, 2018). T can also have significant benefits in transgender men suffering from the anxiety and distress associated with gender dysphoria (Hembree, 2017).

Low levels of testosterone can happen for several reasons, including (Nassar, 2022):

  • Certain cancers, as well as chemotherapy
  • Damage to the pituitary gland (the part of the brain that tells your body to make testosterone)
  • Low levels of certain hormones (including GnRH or gonadotropin-releasing hormone)
  • Obesity
  • Aging (this is the most common cause of low T)

Risks of TRT

As men age, their testosterone levels naturally decline. While it might seem beneficial to administer testosterone to older men, TRT is not officially FDA-approved for age-related hypogonadism. Still, many healthcare providers prescribe testosterone replacement therapy off-label to patients in this category (Saad, 2017). 

Risks of TRT

TRT can be harmful and should be avoided in patients with certain conditions, including (Nassar, 2022):

  • People suffering from heart failure or uncontrolled high blood pressure
  • Those at increased risk for heart attacks
  • Types of breast cancer and prostate cancer
  • Certain blood conditions

TRT is especially risky for those with heart issues; the U.S. Food and Drug Administration (FDA) released an official safety notification to reflect the potential risk of heart problems in certain patients taking testosterone (FDA, 2015). TRT may also increase your risk of hepatic adenomas (a benign or non-cancerous liver tumor) and other liver issues (Nassar, 2022).

Side effects of testosterone replacement therapy

Although rare, it’s possible to have a severe allergic reaction to injectable or topical testosterone. If you experience any severe symptoms (hives, swelling, or shortness of breath), do not take a second dose of testosterone and seek immediate medical care.

Testosterone is a controlled substance and does have the potential for abuse. Taking more than prescribed or using testosterone with anabolic steroids can lead to immediate and life-threatening health consequences like like a heart attack.

Although hormone therapy can be beneficial in many ways, it does come with a risk of adverse effects including (Nassar, 2021):

  • Acne 
  • Pain or itching at the injection or application site
  • Gynecomastia (enlargement of breasts in men)
  • Headaches
  • Benign enlargement of the prostate
  • High blood pressure
  • Increases in calcium levels
  • Edema (fluid retention)
  • Changes in the blood that could lead to increased red blood cell counts and deep vein thrombosis (blood clot)

If you take other medications and are considering starting TRT, talk to a healthcare professional about all of the medicines you take. Also keep in mind that testosterone can have interactions with other medicines you take.