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.