Testosterone Decanoate
Testosterone ester, injectable. Half-life 5.6 days.
Also called Test D
Serum concentration from a single dose
single 100 mg dose over 4 weeks, vertical lines mark each half-life elapsed since the peak
Estimated. No study reports a peak concentration for this compound, so the shape is inferred from the half-life and the level is calibrated against related compounds rather than measured. The height is the least reliable part of this curve.
What the numbers mean
A 5.6 day half-life, most often encountered as the long tail inside blended testosterone products rather than on its own. About 65% of the mass is active testosterone.
The active fraction is the share of each milligram the model treats as reaching circulation as active compound. For an injectable that is ester weight: a milligram of enanthate is not a milligram of testosterone. For an oral it is bioavailability, the share that survives the gut and the liver, which is why some orals sit far below 100%. How the model works.
Where these numbers come from
No published reference is recorded for Testosterone Decanoate. Its figures are carried over from the compound database this plotter was built against, and should be treated as the weakest in the set.
Common questions about Testosterone Decanoate
What is the half-life of Testosterone Decanoate?
The model uses a terminal half-life of 5.6 days for Testosterone Decanoate. For an injectable that figure is the rate the oil depot releases the compound rather than the rate the body clears it, which is why it runs longer than the half-life of the ester itself.
How long does Testosterone Decanoate take to reach steady state?
Roughly 4 weeks, on a schedule that does not change. Steady state is conventionally taken as five half-lives, the point at which each dose is clearing about as fast as the next one arrives, and at a half-life of 5.6 days that puts Testosterone Decanoate at 4 weeks of climbing before the curve flattens.
How long does Testosterone Decanoate stay in your system?
About 4.4 weeks after the last dose for the serum level to fall to a few percent of where it was, on the same five-and-a-half half-life reasoning. That is the modelled blood level only. It is not a detection window: metabolites are found by testing long after the parent compound has gone, and this model says nothing about that.
Put Testosterone Decanoate on a timeline with the rest of your cycle and watch the curves add up.
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