Depo-Testosterone (Testosterone Cypionate)
Pfizer / generic, the injectable workhorse
Evidence grade 5 of 5, Settled. Read how the Atlas grades evidence.
The written rationale for this grade is still being prepared.
- FDA
- FDA Approved (Depo-Testosterone)
Reference only. Not medical advice.
What can go wrong
Biweekly dosing causes serum (and symptom) fluctuation. Polycythemia is the main monitored risk. Injection-site reactions; oil-carrier (cottonseed/grapeseed) allergy is rare.
This is something to take to a clinician. The Atlas can tell you what is known about depo-testosterone (testosterone cypionate) in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
Testosterone cypionate (brand Depo-Testosterone, Pfizer; widely generic) is the most commonly prescribed testosterone in the United States. It is testosterone esterified with cyclopentylpropionic acid to slow release from an oil depot, giving a half-life of roughly 8 days. Standard physiological replacement is ~100-200 mg weekly or biweekly; biweekly dosing produces noticeable peak-trough swings in mood and libido, which is why many clinicians have shifted to weekly or twice-weekly subcutaneous dosing. It is inexpensive (a major reason telehealth markups on it are striking).
The most-prescribed testosterone in the US, cheap, effective, and swingy.
What people take it for
What it is taken for. Approval, where it exists, covers only some of these.
Safety in detail
Requires physician oversight and monitoring (testosterone, hematocrit, PSA). A Schedule III controlled substance.
What it does to fertility
Suppresses spermatogenesis via HPG feedback; not fertility-preserving.
What has to be monitored
The bloodwork this needs, and the reason it belongs with a clinician rather than a website.
- Total testosterone (trough)
- Hematocrit
- PSA (over 40)
What people get wrong
Often saidCypionate and enanthate are clinically different
ActuallyTheir half-lives differ only slightly (~8 vs ~4.5 days) and they are used interchangeably; the choice is largely supply and prescriber preference.
Who profits, and who pushes back
Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.
Set against the alternatives
Versus enanthate: near-identical clinically (cypionate slightly longer half-life). Versus undecanoate (Aveed): far more frequent dosing but no anaphylaxis REMS and far cheaper.
At a glance
- Ester
- Cypionate (cyclopentylpropionate)
- Half-life
- ~8 days
- Typical TRT dose
- 100-200 mg/week or biweekly
- Cost
- Very low wholesale (basis of markup analyses)
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Depo-Testosterone (Testosterone Cypionate). A short entry is not a safe entry.
- Timeline. We have not built the dated record of research and regulatory events.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- Children and teenagers. We have not checked what is known about younger people.
- Where we land. We have not taken a position on this yet.
Sources
No sources recorded for this entry yet. Nothing on this page can be checked against a citation until that changes, so treat it as a summary awaiting its evidence.