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Testosterone Enanthate

Hormone
Strong Evidence
FDA Approved

Also known as: Test E, Delatestryl, Testoviron Depot

Testosterone Enanthate is an injectable testosterone ester widely used for testosterone replacement therapy (TRT) in hypogonadal men. It is one of the most commonly used testosterone formulations globally, particularly in Europe. The enanthate ester provides a half-life of approximately 4-5 days, allowing for weekly or biweekly injections. It has nearly identical pharmacokinetics to testosterone cypionate and is considered interchangeable for clinical purposes.

Half-life

4-5 days

Primary Route

Intramuscular injection

Human Trials

14

Molecular Weight

400.6 Da

Mechanism of Action

Testosterone enanthate acts as a prodrug, releasing testosterone after hydrolysis of the ester bond by tissue esterases. The released testosterone binds to androgen receptors in target tissues including skeletal muscle, bone, adipose tissue, brain, and reproductive organs. It activates genomic pathways by translocating to the nucleus and regulating gene transcription, promoting protein synthesis, muscle growth, bone density maintenance, and male secondary sexual characteristics. Testosterone also converts to DHT via 5-alpha reductase and to estradiol via aromatase.

Research Summary
Strong Evidence

Testosterone enanthate is an FDA-approved injectable testosterone ester with decades of clinical use for testosterone replacement therapy and hypogonadism treatment. Virtually interchangeable with testosterone cypionate, differing only slightly in ester weight and half-life. Extensive evidence supports efficacy in restoring testosterone levels, improving body composition, bone mineral density, sexual function, mood, and energy. Long-acting ester allows weekly or bi-weekly administration. Well-characterized safety profile requiring monitoring of hematocrit, PSA, and lipids.