Testosterone Isocaproate
Testosterone ester, injectable. Half-life 3.1 days.
Also called Test Iso
Serum concentration from a single dose
single 100 mg dose over 15.5 days, 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 3.1 day half-life sitting between propionate and enanthate. Rarely used alone; it usually appears as one of the mid-length components of a blend.
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
The half-life is read from a published reference. No peak concentration has been published, so the height of the curve is calibrated rather than cited. Read it on PubMed Central.
Common questions about Testosterone Isocaproate
What is the half-life of Testosterone Isocaproate?
The model uses a terminal half-life of 3.1 days for Testosterone Isocaproate. 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 Isocaproate take to reach steady state?
Roughly 15.5 days, 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 3.1 days that puts Testosterone Isocaproate at 15.5 days of climbing before the curve flattens.
How long does Testosterone Isocaproate stay in your system?
About 17.1 days 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 Isocaproate on a timeline with the rest of your cycle and watch the curves add up.
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