Actual half lives of esters

[trenbaby]

Seeing a lot of conflicting info regarding the half lives of esters. Lots of people saying 2-3 days for example with Prop compared to now there are a mixed bag of answers with people saying 0.8 days, 1 day, 2-3 days etc. Anyone able to clear up which it is? Seeing the same conflicting info for all esters. Seems no one really knows. I understand it’s best to pin daily/regularly regardless.

 

[pimpman]

Seeing a lot of conflicting info regarding the half lives of esters. Lots of people saying 2-3 days for example with Prop compared to now there are a mixed bag of answers with people saying 0.8 days, 1 day, 2-3 days etc. Anyone able to clear up which it is? Seeing the same conflicting info for all esters. Seems no one really knows. I understand it’s best to pin daily/regularly regardless.

Everyone does know I think you are the one that doesn’t really.

 

[buck]

When i read the manufacturers studies on half life's they seem to have about the same duration. Not sure who you are listening to.

 

[trenbaby]

Everyone does know I think you are the one that doesn’t really.

yes mate clearly. takes a 3 second search to see every post on it have conflicting info.

 

[buck]

Without knowing is some one is talking active or plasma half life the difference can be very big.

 

[specter]

Well one thing is some are faster metabolizer then others, a certain polymorfism can make it so you "burn" through the ester faster then other people, that shows especially in blood samples. Like i was put on TRT on Nebido and my body burnt thru that shit like it was payed to. But as a rule of thumb ester half life is pretty well known.

 

[FrenchBench22]

yes mate clearly. takes a 3 second search to see every post on it have conflicting info.

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There are several reasons that can result in inconsistent results for "halflife."

The terminal half-life and the elimination half-life are two separate things. One measures how long it takes to achieve 50% elimination after peak, the other measures how long to achieve 50% after the final "straight line" slope is achieved (the 4th/5th halflife typically).

These two are drastically different, and the terminal can be more influenced by the type of metabolism pharmacokinetics (single compartment vs 2-compartment 2CPK or multicompartmemt model).

The 3D shape and mass of a molecule also influences its metabolism and excretion, so test phenylpropionate and nandrolone phenylpropionate don't actually have the exact same half-lives based on solely their esters. Nandrolone has I believe a smaller molar mass than testosterone, so it would in theory clear faster, but when attached to phenylpropionate ester chain NPP Is reportedly slower than TPP. Another example of test enanthate and tren enanthate. I think there are studies showing TE with an elimination half-life as fast as 4 days, and TrE something like 7 days.

And completely separate from the chemistry of molecules, every human has different biochemistry that'll influence how fast/slow we metabolize drugs. Enzymes, vascularization of administered tissue, metabolic health, genetics, etc. So two guys that are both 30 years old 180cm 100kg 10% body fat and identical twins can metabolize 200mg Test Enanthate differently depending on lifestyle, diet, sleep, etc. Create a study with hundreds or thousands of people, the results will be all over the place.

Then the studies become the issue. The testing methodology, equipment used, other parameters that can influence testing results, etc. Just the other day I saw a study about halotestin having a half-life of 8 hours, but most studies say it's 2 hours. The methodology for determining the half-life in the 8 hour study didn't use just blood levels of halo, but also factored in how much metabolites were excreted in urine and the density/rate of excretion. Which again can be heavily influenced by that person's liver/kidney health, hydration status, stimulant use, general electrolyte balance, diuresis tendencies, bladder capacity, stress, etc.

I do not think it's possible to say "this molecule's half life is x hours," because it can vary so much. But I do think it's safe to say averages [within standardized testing parameters] can exist. Like we can all agree test prop peaks and clears much faster than test undecanoate.

 

[mexbeast]

There are several reasons that can result in inconsistent results for "halflife."

The terminal half-life and the elimination half-life are two separate things. One measures how long it takes to achieve 50% elimination after peak, the other measures how long to achieve 50% after the final "straight line" slope is achieved (the 4th/5th halflife typically).

These two are drastically different, and the terminal can be more influenced by the type of metabolism pharmacokinetics (single compartment vs 2-compartment 2CPK or multicompartmemt model).

The 3D shape and mass of a molecule also influences its metabolism and excretion, so test phenylpropionate and nandrolone phenylpropionate don't actually have the exact same half-lives based on solely their esters. Nandrolone has I believe a smaller molar mass than testosterone, so it would in theory clear faster, but when attached to phenylpropionate ester chain NPP Is reportedly slower than TPP. Another example of test enanthate and tren enanthate. I think there are studies showing TE with an elimination half-life as fast as 4 days, and TrE something like 7 days.

And completely separate from the chemistry of molecules, every human has different biochemistry that'll influence how fast/slow we metabolize drugs. Enzymes, vascularization of administered tissue, metabolic health, genetics, etc. So two guys that are both 30 years old 180cm 100kg 10% body fat and identical twins can metabolize 200mg Test Enanthate differently depending on lifestyle, diet, sleep, etc. Create a study with hundreds or thousands of people, the results will be all over the place.

Then the studies become the issue. The testing methodology, equipment used, other parameters that can influence testing results, etc. Just the other day I saw a study about halotestin having a half-life of 8 hours, but most studies say it's 2 hours. The methodology for determining the half-life in the 8 hour study didn't use just blood levels of halo, but also factored in how much metabolites were excreted in urine and the density/rate of excretion. Which again can be heavily influenced by that person's liver/kidney health, hydration status, stimulant use, general electrolyte balance, diuresis tendencies, bladder capacity, stress, etc.

I do not think it's possible to say "this molecule's half life is x hours," because it can vary so much. But I do think it's safe to say averages [within standardized testing parameters] can exist. Like we can all agree test prop peaks and clears much faster than test undecanoate.

Best explanation right here!

 

[cage99]

Here’s what I’ve used… Seems to be accurate for how I metabolize things.

Terminal Half Lives:
Testosterone Propionate: 0.8 days
Testosterone Pheny|propionate: 1.5 days
Testosterone Isocaproate: 4.0 days
Testosterone Enanthate: 4.5 days
Testosterone Cypionate: 5.0 days
Testosterone Decanoate: 7.5 days
Testosterone Undecanoate: 20.9 days
Trenbolone Acetate: 1.0 days
Trenbolone Enanthate: 4.5 days
Masteron Propionate: 0.8 days Masteron Enanthate: 4.5 days
Nandrolone Pheny|propionate: 1.5 days
Nandrolone Decanoate: 7.5 days
Equipoise: 14.0 days
Primobolan Oral: 5 hours
Primobolan Injectable: 4.5 days
Halotestin: 7 hours
Anadrol: 14 hours
Dianabol: 5 hours
Turinabol: 16 hours
Winstrol Oral: 8 hours
Winstrol Injectable: 1.0 days
Anavar: 10 hours
Superdrol: 10 hours


Cage

 

[pimpman]

yes mate clearly. takes a 3 second search to see every post on it have conflicting info.

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I was just joking with you mate

 

[LK3]

your test levels are not only due to half life.
different muscles get better absorption then others.
with some esters you get a big spike in initial levels and then some die off faster then others.
maybe your shot could crash en depot. that will changes things too.
often real is life is not linear.

 

[hawkmoon]

Pharmacokinetic outcomes are heavily influenced by specific enzymatic pathways and genetic polymorphisms.

My personal physiological response serves as a direct case study for these variables.
Enzymatic Activity and Ester Preference
Phosphodiesterase 7B (PDE7B) is critical for the hydrolysis of certain esters.

I have observed a diminished response to Testosterone Enanthate compared to Testosterone Cypionate, suggesting a potential inefficiency in my specific PDE7B-mediated cleavage of the enanthate ester.
Carboxylesterase 1 (CES1) Function
CES1 is a primary driver in managing esterified compounds.

Regarding the rs71647871 SNP, I carry the CC genotype, which typically denotes "normal" or "wild-type" function. While my baseline esterase activity is stable, it does not account for the specific cleavage delays I experience with certain compounds.

Cleavage Velocity and Excretion
The rate of ester cleavage and subsequent hormonal clearance is further dictated by:

rs7774640 (Cleavage Speed): I carry the GG variation, which is associated with the slowest cleavage rate (compared to the rapid A/A genotype).

rs7436962 (Testosterone Excretion): I carry the AA genotype, which results in the most rapid excretion of testosterone.

Summary of Individual Pharmacokinetics
In my specific case, the data suggests a "bottleneck" effect: I cleave esters slowly (GG at rs7774640) but excrete the liberated testosterone rapidly (AA at rs7436962). This combination, particularly when using Enanthate, creates a significant deviation from "paper" half-lives.

This underscores the reality that standardized half-life charts are merely averages; individual genetic profiles dictate the actual metabolic reality.