hormoneInjectableControlled

Testosterone Cypionate

Also known as: Test Cyp, Depo-Testosterone

Chemical structure of Testosterone Cypionate (PubChem CID 441404)
Structure via PubChem
Half-life
192 h
Typical timing
any
Food rule
either
Default unit
mg

Studied for

Overview

Testosterone cypionate is an esterified form of the androgen testosterone, a naturally occurring steroid hormone primarily produced in the testes of males and in smaller amounts in the ovaries of females and adrenal glands in both sexes. As a medication, it is categorized as an androgen and an anabolic steroid. It is commonly administered via intramuscular injection and is designed for a sustained release of testosterone, providing a relatively stable level of the hormone over an extended period. This sustained-release property is due to the cypionate ester, which is slowly cleaved from the testosterone molecule *in vivo*, converting it into bioactive testosterone. The primary medical application of testosterone cypionate is in testosterone replacement therapy (TRT) for men diagnosed with hypogonadism, a condition characterized by insufficient testosterone production. It is also used in certain cases for delayed puberty in boys and for specific types of breast cancer in women. (Source: DrugBank, MedlinePlus)

Deep dive

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Known interactions

  • Category rule: peptide × hormone
    Note

    Injectable peptides plus hormones can have overlapping or compounding effects that aren't always well characterized.

    Track bloodwork with a provider; don't assume combinations are neutral.

  • Compound-pair rule
    Synergy

    AI manages estradiol on TRT.

    Titrate AI to target mid-range E2 with bloodwork every 6–8 weeks.

  • Compound-pair rule
    Synergy

    HCG maintains intratesticular testosterone and testicular size during exogenous testosterone use.

    Typical protocol: 250–500 IU HCG 2–3× weekly alongside TRT.

  • Compound-pair rule
    Caution

    5-alpha-reductase inhibitors block DHT conversion; can affect libido and prostate response on TRT.

    Discuss goals with prescribing clinician; monitor sexual function.

  • Compound-pair rule
    Caution

    5-alpha-reductase inhibitors block DHT conversion; can affect libido and prostate response on TRT.

    Discuss goals with prescribing clinician; monitor sexual function.

  • Compound-pair rule
    Caution

    5-alpha-reductase inhibitors block DHT conversion; can affect libido and prostate response on TRT.

    Discuss goals with prescribing clinician; monitor sexual function.

Frequently asked

Sources referenced

["DrugBank","MedlinePlus","PubChem","Mayo Clinic","FDA prescribing information","Cochrane Review","NIH ODS (Office of Dietary Supplements)"]

Stackwise compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician.

Related compounds

Others in the hormone category or studied for the same goals.

Related benefits

Other compounds studied for the same benefits as Testosterone Cypionate.

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