You guys @mnben87 @johann77 are splitting hairs. The “elimination” half-life if 4.5 days. The shot is an ester depot, so it does not all process immediately, thus the “Mean residence time”, commonly referred to as “half-life” because it is the effective half-life, is 7-9 days. You achieve 50% between 7 and 9 days post injection, but technically speaking that is not the half-life.
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Okay, how about this one.
This study actually points to the half life being longer than 8 days. In fact, on average patients only saw about a 27% testosterone reduction at 7 days out (we would expect 50% at 7 days if half life is 7 days).
So the practical half life for use in humans is 7-9 days. I guess I don’t really care what it is in a purely laboratory sense. I just care about half life when injected into a human either IM or SubQ.
Exactly. We’re laymen, and generally using laymen’s terms.
I’m not saying I want to do this I’m saying if it were to happen 3-4 times , I get a little more or less depending on measurement etc , some ppl make it seem like … bam u gtta start your 6 weeks over .
Good study. Take closer look at Figure 1a. Pre injection level is about 500 ng/dl. Day 1 after injection total T is at about 700, thats what we expect. At day 7 the total T level has returned to about 500 ng/dl - pre injection level (residence time is 7 days). If we assume a half life of 7 days T should be at around 600 at day 7.
Another study is the one from Kaminetsky et al, 2015 (linked below). Take a look at Figure 2. In the 50 mg injection patients the T level returns to pre injection levels on day 7, ie again all the T that you have injected 7 days before is cleared from the system (residence time). In the 100 mg injection, a portion of the injection remains in the system at day 7, and thats why you see an accumulation over several injections.
Sokol et al, 1982, (linked also below). Figures 1 to 4. oOne can nicely see the high intersubject variability.
Eugonadal man: The apparent half-life was 3.8 days.
Hypogonadal man: The apparent half-life was 4.2 days.
We are mixing up here the terms ‘half life’ - the period after which 50% of the drug is cleared with ‘mean residence time’ - the time it takes until 99% of the drug is cleared.
https://www.fertstert.org/article/S0015-0282(16)46108-X/pdf
Guys I have a total of 12 years education in the field of biochemistry and molecular medicine and more then 10 years experience in drug discovery and research.
What drop can you figure for production shutdown? Or was the subject in shutdown before the study started by use of a non-testosterone androgen?
I would expect that if one measured total testosterone at 700, then 7 days later if we measured total testosterone we would measure 350 (if half life is 7 days).
The math is complicated because after a shot there is an offset ramp up, a peak, then exponential decay. If we were to measure the test at peak, and then every day after, we should expect that when the time of one half life of the drug has passed, that half the total of the drug is present compared to peak, right?
Patients in the first study are females, no shut down. 500 is trough level of last injection.
Patients inject weekly T and the kinetics was done after multiple weeks of T injections (steady state).
So a thought I had that makes the math a bit more complicated here is that although we reach a peak, the newest shot will continue to release testosterone (and to a lesser extent from shots even further back).
We would need to understand the release curve of testosterone C, to be able to understand half life using the graph from the study I posted. Basically we have new test that is releasing, and old test that is decaying, we know that the peak is where the decay rate = the release rate, but we don’t know the release rate, and that makes inferring anything from that graph pretty tough.
Edit: I think this is what you were trying to say, by saying they are at steady state. I did not put that together until know.
I see some logic in your words, but Defy and another top doctor precisely advised me it is best to use daily cypionate or enanthate. We have not discussed the cream, I do not want it for now due to the possibility of making me more aggressive because of the DHT. For propinate I dont know, but they did not recommend it.
I have a question for you: Its probably a bro science from steroid users, but is it true if you start testosterone and for example decide to cut therapy after a couple of months it is much easier to recover from enanthate than cypionate? And cypionate was the hardest to restart from? The logic was this has to do with the total amount of time it is in your system.
If you take a longer ester for the same time, the shutdown time is going to be greater. I think it will be negligible in TRT realm.
I could see doing like an 8 week cycle of Test P vs a 10 week cycle of Test C as advantageous for someone cycling, but even then it is likely not a big difference.
Nope. One is not going to be any different than the other in that regard.
I think it would be just slightly different (you might need an extra couple hours before PCT with Test C), but in the realm of practicality it is the same.
I believe it would be negligible, but that does not mean that they are the same.
I can tell you all without a shadow of a doubt the following;
All from personal experience and blood work done twice a week:
Test enanthate is by far superior then cypionate. I don’t care that they’re only one molecule different ester wise
Enanthate hits you harder and faster but drops quick by day 4-5
Cypionate feels like injecting water but lasts much longer a blood draw at day 4 post injecting 70 mg had me at 960 ng/dl
Enanthate by day 5 had me at 600 ng/dl but don’t let that fool you.
I feel best with a hard initial spike and not a super high trough.
All in all my cypionate experience was garbage. On paper numbers looked great. In reality I felt nothing. No libido
On enanthate I can still to this day feel a dopamine rush sometimes as soon as half hour after injection.
