This information is for research and educational purposes only. No medical recommendations. Products are not approved for human use. For health questions, consult a doctor.

Lexicon

Muscle & performance

Testosterone Cypionate

The second big long testosterone ester - practically identical to test enanthate.

1 min read 1 sources Titration Updated June 2026
Class
Testosterone ester (long-acting)
Use
Intramuscular or subcutaneous, 1-2x per week
Half-life
about 5-6 days
WADA
banned (anabolic)

Getting started

Typical dosing (research context)

Per-week figures in mg, split across 2 injections. Practically interchangeable with test enanthate.

Members only

Dosing recommendations are visible to logged-in members only. Logging in is free.

Log in / sign up

What is Testosterone Cypionate?

Testosterone Cypionate (Test C) is testosterone with a cypionate ester. In practice it is nearly identical to Testosterone Enanthate - the esters differ by just one carbon atom, the half-life is marginally longer. In the US, cypionate is the traditionally more common TRT ester, in Europe it tends to be enanthate.

This information is for research and educational purposes only. No medical advice.

How it works

Identical to test enanthate: androgen receptor activation, increased protein synthesis, nitrogen retention and erythropoiesis. Partial conversion to estradiol via aromatase.

Cypionate vs enanthate

The practical difference is negligible. Cypionate has a marginally longer half-life, both are injected 1-2x per week. If one works for you, so does the other. The choice is usually a matter of availability and habit.

Dosing

Members only

Dosing recommendations are visible to logged-in members only. Logging in is free.

Log in / sign up

What the research shows

Testosterone research applies to all esters equally, because once the ester is cleaved the same testosterone acts. The Bhasin study (NEJM, 1996) is the reference for the dose-dependent anabolic effect.

Side effects

  • Estrogen-related: water retention, gyno risk.
  • Possible hematocrit rise.
  • HPTA suppression - PCT topic.
  • Androgenic: acne, hair loss in predisposed individuals.

Storage

Store the oil solution at room temperature, protected from light - no fridge needed. Out of reach of children.

Practice

PCT / after coming off

Anabolic substances suppress the body's own testosterone production in the research context. Anyone who comes off a cycle (rather than running it continuously) typically uses a post-cycle therapy (PCT) to restart the natural axis (HPTA).

The standard scheme in the research/literature context combines a SERM (tamoxifen and/or clomifene, alternatively enclomiphene) over roughly four weeks, optionally preceded by HCG to re-sensitise the testes before the SERM block. An aromatase inhibitor (anastrozole/exemestane) belongs more to on-cycle estrogen control than to the PCT itself.

Tip: order the PCT items together with the cycle so they are already on hand when you come off.

This information serves research and educational purposes only. Not medical advice.

Evidence

Sources

  1. 1 Supraphysiologic testosterone doses increase muscle size and strength in healthy men. Bhasin et al., NEJM, 1996

Keep reading

More in the lexicon

In the shop

Testosterone Cypionate in the catalog

Sizes, prices and availability for research use. Straight from the lexicon to the product page.

View in shop