Without having your particular dose-response relationship there's enough guesswork to make the accuracy of the prediction pretty questionable. But here it is: Assume a serum T peak at one day post-injection, followed by an exponential decay of 2 days, and a T cypionate half-life of 5 days. So Peak * exp(-ln(2)/5*2) = 747 ng/dL. This puts the peak at 986 ng/dL.
This is not correct. The apparent half-lives of testosterone esters are essentially not affected by SHBG. The half-lives are governed by the slow rate of absorption of the injected depots.
I also used to think it was longer, but then @madman called me on it, and after researching it further I had to concede the point. The references supporting the 5-day figure are much stronger, and 90+% of the anecdotal results in the forums also points to 5 days.
This can't be answered there's no part of this that is linear like that. The best course of action is to start doing your routine like most other people do, you choose to be different in that regard; Mon AM, Thurs PM, blood draw Mon AM before shot.
As I recall, madman pointed out that there are flaws in the studies coming up with the longer half-life. When corrected they also point to ~5 days as the half-life. I would stick with this figure.
The equation uses time after peak, not time before, with the peak occurring right at zero time:
Your first two measurements give a reasonable half-life of 23 days. The final measurement is indeed much higher than if there were a continued exponential decay. This just shows the shortcomings of the model and/or a measurement anomaly.
Alternatively, you could toss the middle measurement, in which case the half-life is calculated as 35 days, and the predicted peak is 1,930 ng/dL.
As I recall, madman pointed out that there are flaws in the studies coming up with the longer half-life. When corrected they also point to ~5 days as the half-life. I would stick with this figure.
The equation uses time after peak, not time before, with the peak occurring right at zero time:
T(time_after_peak) = Peak * exp(-ln(2) / half_life * time_after_peak)
The model just assumes a pure exponential decay after the peak serum level is reached.
I'd been thinking it's longer, but it seems to be around a week.
Your first two measurements give a reasonable half-life of 23 days. The final measurement is indeed much higher than if there were a continued exponential decay. This just shows the shortcomings of the model and/or a measurement anomaly.
If we assume a one-week post-injection delay to peak then we can work backwards using your 23-day half-life to find that your peak testosterone is estimated to be 2,200 ng/dL.
So 16 days after your first Nebido injection you measured 1,389 ng/dL, and the time you measured 1,492 was 20 days after a subsequent injection? If so the latter is expected to be higher because the Nebido was still accumulating.
