Testosterone cypionate

Anabolic steroids

Also known as Test C, Depo-Testosterone

Near-identical in behaviour to enanthate; the ester common in the United States.

How it works

An eight-carbon cyclopentylpropionate ester of testosterone. Slightly heavier than enanthate, and released from the depot at a very similar rate.

IntramuscularSubcutaneous

In the body

Half-life

4.5 days

Time to peak

2 d

90% gone after

14.9 d

Builds up to

1.52×

Steady state after about 22.8 d at weekly, often split into two injections.

Shape of a single dose, modelled as one compartment with first-order absorption. The peak is normalised to 100% because bioavailability and volume of distribution are not published for most of these compounds.

Given as comparable to enanthate, around 4.5 days, in direct comparisons. A figure of about 8 days is widely repeated online; it traces to a single older estimate and is not what head-to-head measurements show.

Doses

50 mg, 100 mgweekly, often split into two injectionsApproved label

Replacement dosing. The label also describes 50 to 400 mg every two to four weeks, a schedule that produces a much larger swing between peak and trough.

Vial sizes

2000 mg2500 mg

Side effects

As testosterone enanthate, raised haematocrit, acne, oestradiol effects, testicular atrophy, hair loss in those predisposed
Monitor: Haematocrit, androgens raise red cell mass, and the rise is dose-dependent
Monitor: Blood pressure
Monitor: Lipids, especially a fall in HDL
Monitor: Total and free testosterone, LH and FSH
Monitor: Oestradiol, for the aromatising compounds

Cautions

Prostate or breast cancer
Trying to conceive
Untreated severe sleep apnoea
Polycythaemia
Pregnancy

Status

Prescription-only, Schedule III in the United States. Banned in sport at all times.

Sources

Reference information for personal record-keeping. Not medical advice, and not a recommendation to use any of these compounds.