Injectable esters commonly used by trans men for testosterone therapy:
Testosterone enanthate: Chemical formula C26H40O3
Testosterone enanthate is one of the main forms of testosterone prescribed to trans men in the United States. It is a slow-acting ester with a release time between 8-10 days. The name-brand of T-enanthate available in the United States is called "Delatestryl," which is suspended in sesame oil. Testosterone enanthate is typically injected anywhere between once every week to once every three weeks. Generic testosterone enanthate can also be obtained through a compounding pharmacy; such pharmacies can mix the enanthate in either sesame or cotton seed oil. (For more information about compounding pharmacies, click here.)
Testosterone cypionate: Chemical formula C27H40O3
Testosterone cypionate is the other main injectable form of testosterone prescribed to trans men in the United States. It is a slow-acting ester with a release time between 8-10 days, similar to that of enanthate. The name-brand of T-cypionate available in the United States is called "Depo-Testosterone," which is suspended in cottonseed oil. Testosterone cypionate is typically injected anywhere between once every week to once every three weeks. Generic testosterone cypionate can also be obtained through a compounding pharmacy; such pharmacies can mix the cypionate in either sesame or cotton seed oil. (For more information about compounding pharmacies, click here.)
Sustanon 100 or 250
"Sustanon" is the brand name for two formulas of injectable testosterone that contain a blend of esters. "Sustanon 100" contains three testosterone esters: testosterone propionate (C22H32O3), testosterone phenylpropionate (C28H36O3), and testosterone isocaproate (C25H3803). "Sustanon 250" contains four testosterone esters: testosterone propionate (C22H32O3), testosterone phenylpropionate (C28H36O3), testosterone isocaproate (C25H3803), and testosterone decanoate (C29H4603). Both formulas feature both fast-acting and slow-acting esters, and can be injected anywhere from once every week to once every four weeks. Sustanon is prescribed outside of the United States.
Other injectable esters of testosterone:
Testosterone propionate: Chemical formula C22H32O3
Testosterone propionate is a fast-acting ester with a release time of 3-4 days. To keep blood levels from fluctuating greatly, propionate is usually injected between one to three times a week. It is for this reason that it is not usually prescribed for FTM hormone therapy. Some users also report that propionate is a more painful injection, with swelling and noticeable pain around the injection site. Brand names of testosterone propionate include "Testovis" and "Virormone."
Testosterone phenylpropionate: Chemical formula C28H36O3
Testosterone phenylpropionate is a slow-acting ester, with a release time of 1-3 weeks. A popular name brand for T-phenylpropionate is "Testolent." Testosterone phenylpropionate is also one of the components of Sustanon and Omnadren.
Omnadren
"Omnadren" is the brand name for a blend of four testosterone esters: testosterone propionate (C22H32O3), testosterone phenylpropionate (C28H36O3), testosterone isocaproate (C25H3803), and testosterone decanoate (C29H4603). In the past, Omnadren consisted of a blend of different esters, but now is essentially the same formula as Sustanon, mentioned above. It features both fast-acting and slow-acting esters, and can be injected anywhere from once every week to once every four weeks. It is sometimes prescribed in parts of Europe.
Aqueous testosterone suspension
In the United States, injectable aqueous (non-esterified) testosterone is available, but it is very short-acting (it is completely released in the system within a matter of hours). Therefore, it is not typically used for men in transition, as it would require constant re-injection to maintain regular blood levels. The brand name for aqueous testosterone suspension is "Aquaviron."