Below is a discussion of common testosterone esters. The primary difference between esters is the rate at which testosterone enters the bloodstream following an injection. A slower release means fewer testosterone injections per year. Testosterone propionate is a fast-acting ester rarely used in TRT (Testosterone Replacement Therapy). Testosterone enanthate and testosterone cypionate are slow-acting injectable forms. They have been the predominant form used for TRT. Testosterone undecanoate is a newly approved form that is very long-acting.
Testosterone Cypionate
Testosterone cypionate is a slow-acting injectable form of the androgen testosterone. Following deep intramuscular injection, the drug provides a sustained release of testosterone into the bloodstream for up to 2 weeks. Testosterone cypionate possesses a half-life of about 5-8 days. The most commonly recommended dosing regimen for TRT is is 120 to 160 mg every week or 150 to 200 mg every other week. Typically, 26-52 injections are required per year.
Testosterone Enanthate
Similar to testosterone cypionate, testosterone enanthate is a slow-acting injectable form of the androgen testosterone. Following deep intramuscular injection, the drug provides a sustained release of testosterone into the bloodstream for up to 2 weeks. Testosterone enanthate possesses a half-life of 5-8 days. The most commonly recommended dosing regimen for TRT is is 120 to 160 mg every week or 150 to 200 mg every other week. Typically, 26-52 injections are required per year.
Testosterone Propionate
In comparison to testosterone enanthate and testosterone cypionate, testosterone propionate is a faster-acting form of the androgen testosterone. Testosterone propionate possesses a half-life of roughly 2-3 days. Therefore, testosterone propionate does not provide a sustained release. Due to this short half-life, it must be injected every third or fourth day. As a result, it isn't as commonly used for TRT.
Testosterone Undecanoate
Testosterone Undecanoate is available as brand name AVEED®. This ester is one of the longest acting, with studies showing that Testosterone levels remained elevated for roughly three months post-injection. Injections are typically every 90 days, and protocols vary based on the patient’s response. There are some compounding pharmacies that do make this type of testosterone.
See the most common forms of injectable testosterone here.
