What it is
A long-acting esterified form of testosterone in oil suspension, structurally similar to cypionate with one less carbon in the ester chain.
How it works
The enanthate ester is hydrolyzed by serum esterases following injection, releasing testosterone that activates androgen receptors in target tissues.
Where it's used
Used in hormone replacement therapy for men with hypogonadism; also approved as an autoinjector formulation (Xyosted).
FDA-approved use
Replacement therapy in conditions associated with a deficiency or absence of endogenous testosterone in males.
Tracking it
Testosterone Enanthate is injectable, so two things matter in a log: when you dosed and where. Rotating sites and writing both down prevents the classic “did I already pin the left side?” problem. with a half-life of about 7 days (168 h), a dose log also lets a tracker model the relative amount still in your system between doses.
Source
OpenFDA
Last reviewed 2026-06-11