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General half life times

GreatGunz

GreatGunz

VIP
Jun 10, 2011
1,667
167
I borrowed this did not write it!

*Note: The determined half-lives are only estimations. After performing a PCT calculation, an error margin of a few days should be considered. If you have any information that may be of aid to us, feel free to email us!
Propionate: 2 days
Reasoning: From analyzing graphs we determined that total testosterone levels began their drop 24 h after a single injection of 50mg testosterone propionate (1). Further analysis discovered levels were halved approximately 2 days after injection, and so that is the estimated half-life of the propionate ester.
Phenylpropionate: 3 days
Reasoning: Data revealed nandrolone phenylpropionate to have a little bit longer of a half-life than that of propionate (2). Although there have not been many studies done using the ester, it's estimated half-life is 3 days.
Isocaproate: 5 days
Reasoning: With a shorter ester than that of enanthate and longer than that of phenylpropionate, the isocaproate half-life is rougly estimated to have a 5 day half-life. This is based on the carbon composition of the ester alone as there exists very little known studies on this ester.
Enanthate: 7 days
Reasoning: From analyzing many graphs and data tables concerning the half-lives of testosterone enanthate(1, 4, 5), it was concluded that the half-life was measured to be about 7 days. We noted that weekly injections of 200mg TE resulted in a continual rise in total testosterone levels until it plateaued at 12 weeks (3). The total testosterone levels between the 8th and 12th week were not significantly different signifying that an estimated half-life of 7 days properly fit the calculated predictions for testosterone levels.
Cypionate: 7 days
Reasoning: Differing from enanthate by only 1 carbon atom, the cypionate ester has no noticeable changes in half-life from enanthate (1). Thus it shares the same, 7 days.
Decanoate: 9.5 days
Reasoning: Being 3 carbon atoms longer, this ester should have an extended half-life over enanthate. This is shown evidently in studies done on single-shot injections of Nandrolone Decanoate (3). The half-life varied from 7-12 days leaning more towards 12 days depending on injection site. We took the average of that which was 9.5.
Undecanoate: 34 days
Reasoning: From detailed graphs and also clinically calculated half-lifes in (1), the estimated half-life of the undecanoate is an impressive 34 days. Definitely not an ester to use for short cycles.
 
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MuscleHead
Sep 9, 2010
3,442
648
The most interesting thing about half lives and peak plasma levels is that according to a few studies I've seen, the numbers actually depend on WHERE you are injecting. Nandrolone Decanoate injected in the glutes resulted in a higher peak plasma level than the same amount injected into the deltoid. I wish I still had that study.... I'll look for it.
 

SHINE

Friends Remembered
Oct 11, 2010
5,047
600
I borrowed this did not write it!

*Note: The determined half-lives are only estimations. After performing a PCT calculation, an error margin of a few days should be considered. If you have any information that may be of aid to us, feel free to email us!
Propionate: 2 days
Reasoning: From analyzing graphs we determined that total testosterone levels began their drop 24 h after a single injection of 50mg testosterone propionate (1). Further analysis discovered levels were halved approximately 2 days after injection, and so that is the estimated half-life of the propionate ester.
Phenylpropionate: 3 days
Reasoning: Data revealed nandrolone phenylpropionate to have a little bit longer of a half-life than that of propionate (2). Although there have not been many studies done using the ester, it's estimated half-life is 3 days.
Isocaproate: 5 days
Reasoning: With a shorter ester than that of enanthate and longer than that of phenylpropionate, the isocaproate half-life is rougly estimated to have a 5 day half-life. This is based on the carbon composition of the ester alone as there exists very little known studies on this ester.
Enanthate: 7 days
Reasoning: From analyzing many graphs and data tables concerning the half-lives of testosterone enanthate(1, 4, 5), it was concluded that the half-life was measured to be about 7 days. We noted that weekly injections of 200mg TE resulted in a continual rise in total testosterone levels until it plateaued at 12 weeks (3). The total testosterone levels between the 8th and 12th week were not significantly different signifying that an estimated half-life of 7 days properly fit the calculated predictions for testosterone levels.
Cypionate: 7 days
Reasoning: Differing from enanthate by only 1 carbon atom, the cypionate ester has no noticeable changes in half-life from enanthate (1). Thus it shares the same, 7 days.
Decanoate: 9.5 days
Reasoning: Being 3 carbon atoms longer, this ester should have an extended half-life over enanthate. This is shown evidently in studies done on single-shot injections of Nandrolone Decanoate (3). The half-life varied from 7-12 days leaning more towards 12 days depending on injection site. We took the average of that which was 9.5.
Undecanoate: 34 days
Reasoning: From detailed graphs and also clinically calculated half-lifes in (1), the estimated half-life of the undecanoate is an impressive 34 days. Definitely not an ester to use for short cycles.

Good job Gunz! Those are realy good examples of true half-lives of varying esters taken from clinical studies. And true the half-lives although acurate for the people of those studies done with testing should be considered an estimate. Everyone does metabolize esters at different rates, (biochemical individuality) as well as other factors like Exercise, site of injection, proper injection technique (not going deep enuff will alow the depot to escape in the facia slowing release/absorption) scar tissue build up, and also the vehicle/carrier used to carry the hormone. Example below showing the half-life of test undecanoate in castor oil and Tea seed oil. Castor oil extended the half-life over 10 days of tea seed oil.

Intramuscular injection of testosterone undecanoat... [Eur J Endocrinol. 1999] - PubMed result
castor oil preparation had a longer half-life than TU in tea seed oil (33.9+/-4.9 vs 20.9+/-6.0 days (mean pm S.E.M.)).
 
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SHINE

Friends Remembered
Oct 11, 2010
5,047
600
The most interesting thing about half lives and peak plasma levels is that according to a few studies I've seen, the numbers actually depend on WHERE you are injecting. Nandrolone Decanoate injected in the glutes resulted in a higher peak plasma level than the same amount injected into the deltoid. I wish I still had that study.... I'll look for it.


This one is a bit easier to read than the minto, same study. Excellent study of decanoate and phenlypropionate esters.

http://jpet.aspetjournals.org/content/281/1/93.full.pdf
 
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gunrunner

gunrunner

Senior Member
Jul 24, 2013
193
21
How long it stays in your system is not just a matter of the ester used but the drug itself. Primo Enanthate isn't as active as long as Test E and that is why it needs administered more often. I had issues with PCT before and had Dr Scally reviewed my lab work and he informed me that the exogenous gear was still active and needed to clear before I started PCT. He posted some interesting studies on how NPP will stay in the system a loooooooong time and delay PCT and recovery. Now Deca or Sust that will really **** up your PCT timing.
 
GapeVanDamme

GapeVanDamme

Member
Jan 24, 2014
15
2
New member here, and I'm not sure if this has been posted before, but this is a useful website to get an estimation of where your blood levels will be with different compounds.

Edit: I don't have a high enough post count for links, I guess. Anyways, steroidplot.com
 
dr jim

dr jim

MuscleHead
Apr 7, 2014
785
168
Damn good work mates, however I would suggest the following modifications.

I borrowed this did not write it!

*Note: The determined half-lives are only estimations. After performing a PCT calculation, an error margin of a few days should be considered. If you have any information that may be of aid to us, feel free to email us!
Propionate: 2 days

Reasoning: From analyzing graphs we determined that total testosterone levels began their drop 24 h after a single injection of 50mg testosterone propionate (1). Further analysis discovered levels were halved approximately 2 days after injection, and so that is the estimated half-life of the propionate ester.

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Because once PCT is commenced STEADY STATE LEVELS have already been achieved the half life timing should BEGIN after the PEAK value has passed. This adds another 24 HOURS to the "half life" of essentially, ANY AAS being cycled. For example in the situation Iv'e underlined the time ZERO to determine testosterones half life BEGINS after 24 HOURS.

This is important because before reliable SS levels can be achieved, a drug must reach it's maximal volume of distribution. The VD involves factors which can SIGNIFICANTLY alter the AAS serum level. Included are SHBG, Albumin, the interstitial space and intravascular spaces.

Thereafter further declines in the AAS level would be ASSUMED secondary to TWO primary processes. The first is SKM uptake for anabolism and the second is either hepatic or renal elimination.

In summary once the VD is maximized, STEADY STATE levels are assured, and no additional dosing is anticipated, an AAS half life may be ESTIMATED by analyzing the time required for the drug level to be reduced by one half.

Regards
JIM
 
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