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.

Your notes

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.