Active Half lives of AAS and Esters (Stolen from OSB)

[Dk]

I always find myself going over to OSB to look at this chart, so i figured might as well have it here

"Active Half-life of Steroids and Esters

An important consideration when planning a steroid cycle, in particular the timing of dosing to be administered, is the active half-life of the drug being employed. The half-life may be defined as the time (t) the level is half of the starting level of a given compound; at time 2t, the level is a quarter of the starting level, and at time 3t, the level is an eighth of the starting level, and so on.

This information is vital in the timing of the dosing when attempting to achieve a more stable blood concentration, which leads to greater overall results and maintenance of gains. Some fluctuations of concentration levels are acceptable, and are also mostly unavoidable, but should be kept to a minimum.


Oral steroids

Drug Active half-life
Anadrol / Anapolan50 (oxymetholone) 8 to 9 hours
Anavar (oxandrolone) 9 hours
Dianabol (methandrostenolone, methandienone) 4.5 to 6 hours
Methyltestosterone 4 days
Winstrol (stanozolol)
(tablets or depot taken orally) 9 hours


Depot steroids

Drug Active half-life
Deca-durabolin (Nandrolone decanate) 15 days
Equipoise 14 days
Finaject (trenbolone acetate) 3 days
Primobolan (methenolone enanthate) 10.5 days
Sustanon or Omnadren 15 to 18 days
Testosterone Cypionate 12 days
Testosterone Enanthate 10.5 days
Testosterone Propionate 4.5 days
Testosterone Suspension 1 day
* Winstrol (stanozolol) 1 day



Steroid esters

Drug Active half-life
Formate 1.5 days
Acetate 3 days
Propionate 4.5 days
Phenylpropionate 4.5 days
Butyrate 6 days
Valerate 7.5 days
Hexanoate 9 days
Caproate 9 days
Isocaproate 9 days
Heptanoate 10.5 days
Enanthate 10.5 days
Octanoate 12 days
Cypionate 12 days
Nonanoate 13.5 days
Decanoate 15 days
Undecanoate 16.5 days



Ancillaries

Drug Active half-life
Arimidex 3 days
Clenbuterol 1.5 days
Clomid 5 days
Cytadren 6 hours
Ephedrine 6 hours
T3 10 hours


A practical example is if one was to inject 100mg of testosterone propionate and allow blood levels to peak. In 4.5 days time (half-life duration from the above tables) and providing no other injections had taken place, the level would be reduced to 50mg. Again, a further 4.5 days down the line and levels would have dropped to 25mg, and the value keeps halving every 4.5 days."

[purelife]

sweet thnx for the info

[faller]

Needs to be sticky for quick reference.

[pinhead]

good info to have around

[nitrous]

Needs to be sticky for quick reference.

agreed

[Dk]

bump then

[Namelessone]

Agreed, make this a sticky.

Thanks for the info!

[Body By Balco]

Delete it...its garbage (no disrespect to the poster)


It uses for the injectable esters a bogus rule of thumb of 1.5 days of half life for every carbon in the ester. Who made this fairy tale up and how it still perpetuates itsefl is FAR beyond me.

The 1.5 rule has ZERO science, that I can find, to back it up. I'll begin to poke holes in it with some actual science.......

Both examples relate to Nandrolone Decanoate


J Steroid Biochem. 1985 May;22(5):623-9.Links
Pharmacokinetics of 19-nortestosterone esters in normal men.Belkien L, Schürmeyer T, Hano R, Gunnarsson PO, Nieschlag E.
A reliable method for the isolation of 19-nortestosterone (NT), testosterone (T) and dihydrotestosterone (DHT) by high-performance liquid chromatography (HPLC) and quantitation of the individual steroids by radioimmunoassays is described. The method was used to measure serum concentrations of NT, T and DHT in a pharmacokinetic study and in a clinical trial for male fertility control. Following intramuscular injection of either 50 mg 19-nortestosterone-3-(p-hexoxyphenyl)-propionate (NP) or 50 mg 19-nortestosterone-decanoate (ND) serum NT increased rapidly to maximal concentrations of 4.6 +/- 3.2 and 2.0 +/- 1.3 nmol/l (+/-SD), respectively, in the 6 volunteers. The half-life time was 8 days for ND and 21 days for NP. Based on these findings a clinical trial with NP was performed. NP was given to 5 healthy men in doses of 100 mg/week for the first 3 weeks followed by 200 mg/week for 10 further weeks. Serum NT levels increased gradually and maximal concentrations were reached in the 13th treatment week (20.2 +/- 3.4 nmol/l). Measurable amounts of NT were detectable for 19 weeks after the last injection. The study shows that NT accumulates under this treatment regime and wider spacing of the injection intervals may be possible in future trials.


1: Acta Endocrinol Suppl (Copenh). 1985;271:19-30.Links
Pharmacokinetic parameters of nandrolone (19-nortestosterone) after intramuscular administration of nandrolone decanoate (Deca-Durabolin) to healthy volunteers.Wijnand HP, Bosch AM, Donker CW.
Nandrolone decanoate (Deca-Durabolin) was injected intramuscularly into healthy volunteers. One group of females received one injection of 100 mg and three groups of males received one injection of 200 mg, two repeat injections of 100 mg or four repeat injections of 50 mg respectively. The serum levels of nandrolone (19-nortestosterone) were determined by radioimmunoassay and used to estimate pharmacokinetic parameters. The following pharmacokinetic parameters were found: a mean half-life of 6 days for the release of the ester from the muscular injection depot into the general circulation; a mean half-life of 4.3 h for the combined processes of hydrolysis of nandrolone decanoate and of distribution and elimination of nandrolone; a mean nandrolone serum clearance of 1.55 1 X h-1 X kg-1. The half-life of hydrolysis of nandrolone decanoate in serum was of the order of one hour or less. The data are consistent with linear kinetics.






I'll likely leave it at this, but TRUST me, those half life approximations are WAYYYYY to long.

[Dk]

Delete it...its garbage (no disrespect to the poster)


It uses for the injectable esters a bogus rule of thumb of 1.5 days of half life for every carbon in the ester. Who made this fairy tale up and how it still perpetuates itsefl is FAR beyond me.

The 1.5 rule has ZERO science, that I can find, to back it up. I'll begin to poke holes in it with some actual science.......

Both examples relate to Nandrolone Decanoate


J Steroid Biochem. 1985 May;22(5):623-9.Links
Pharmacokinetics of 19-nortestosterone esters in normal men.Belkien L, Schürmeyer T, Hano R, Gunnarsson PO, Nieschlag E.
A reliable method for the isolation of 19-nortestosterone (NT), testosterone (T) and dihydrotestosterone (DHT) by high-performance liquid chromatography (HPLC) and quantitation of the individual steroids by radioimmunoassays is described. The method was used to measure serum concentrations of NT, T and DHT in a pharmacokinetic study and in a clinical trial for male fertility control. Following intramuscular injection of either 50 mg 19-nortestosterone-3-(p-hexoxyphenyl)-propionate (NP) or 50 mg 19-nortestosterone-decanoate (ND) serum NT increased rapidly to maximal concentrations of 4.6 +/- 3.2 and 2.0 +/- 1.3 nmol/l (+/-SD), respectively, in the 6 volunteers. The half-life time was 8 days for ND and 21 days for NP. Based on these findings a clinical trial with NP was performed. NP was given to 5 healthy men in doses of 100 mg/week for the first 3 weeks followed by 200 mg/week for 10 further weeks. Serum NT levels increased gradually and maximal concentrations were reached in the 13th treatment week (20.2 +/- 3.4 nmol/l). Measurable amounts of NT were detectable for 19 weeks after the last injection. The study shows that NT accumulates under this treatment regime and wider spacing of the injection intervals may be possible in future trials.


1: Acta Endocrinol Suppl (Copenh). 1985;271:19-30.Links
Pharmacokinetic parameters of nandrolone (19-nortestosterone) after intramuscular administration of nandrolone decanoate (Deca-Durabolin) to healthy volunteers.Wijnand HP, Bosch AM, Donker CW.
Nandrolone decanoate (Deca-Durabolin) was injected intramuscularly into healthy volunteers. One group of females received one injection of 100 mg and three groups of males received one injection of 200 mg, two repeat injections of 100 mg or four repeat injections of 50 mg respectively. The serum levels of nandrolone (19-nortestosterone) were determined by radioimmunoassay and used to estimate pharmacokinetic parameters. The following pharmacokinetic parameters were found: a mean half-life of 6 days for the release of the ester from the muscular injection depot into the general circulation; a mean half-life of 4.3 h for the combined processes of hydrolysis of nandrolone decanoate and of distribution and elimination of nandrolone; a mean nandrolone serum clearance of 1.55 1 X h-1 X kg-1. The half-life of hydrolysis of nandrolone decanoate in serum was of the order of one hour or less. The data are consistent with linear kinetics.






I'll likely leave it at this, but TRUST me, those half life approximations are WAYYYYY to long.

mind fixing it then? haha, because i use this chart alot

[Body By Balco]

mind fixing it then? haha, because i use this chart alot



For linear esters (straight carbon chains) approximate with 0.7 X the number of carbons in the ester. Cyclical esters (cypionate for example which is cyclopentylpropionate) are metabolised differently and there are no easy approximations based on structure. Having said that, cyp and enan esters are still relatively close in thier pharmacokinetics.


As well having said ALL of that, more frequent injections of small doses, be it ED or EOD REGARDLESS of the ester, is best. You will reduce you need for SERMs and AIs, experience less side effects, and grow consistently well obtaining more bang for your dollar spent.

[pinhead]

Ah...BBB. We missed you. Welcome back :) You're posts always make me concentrate and actually have to think. Thank you.

[O-Train]

For linear esters (straight carbon chains) approximate with 0.7 X the number of carbons in the ester. Cyclical esters (cypionate for example which is cyclopentylpropionate) are metabolised differently and there are no easy approximations based on structure. Having said that, cyp and enan esters are still relatively close in thier pharmacokinetics.


As well having said ALL of that, more frequent injections of small doses, be it ED or EOD REGARDLESS of the ester, is best. You will reduce you need for SERMs and AIs, experience less side effects, and grow consistently well obtaining more bang for your dollar spent.

Ok this is purely a hypothetical question because I'm just curious about stuff. Let's say you wanted to take Test E 500mg. So first shot is 500mg and t1/2 is about 5 days. So every 2.5 days you pin 250mg? Or would you still do ED/EOD?

[varking]

thanks for the great post

[faller]

I don't know about you guys but this just opened up a whole can of worms for me. http://i118.photobucket.com/albums/o113/faller11/smilies/confused.gif

[Body By Balco]

Ok this is purely a hypothetical question because I'm just curious about stuff. Let's say you wanted to take Test E 500mg. So first shot is 500mg and t1/2 is about 5 days. So every 2.5 days you pin 250mg? Or would you still do ED/EOD?




In theory take 75mg ED. Find a nice little 1cc tuberculin slip tip syringe (not an insulin rig) and the dosing will be easier, or take 150 EOD as it is likely more practical given this dosing scenario. [On the assumption that the steroid is concentrated at 250mg/ml] You'll only be slightly more than 500mg per week.

Obtaining parenteral oils that are of suffciently low viscosity to enable passage through a 25g needle or preferably a 27g (there are 27g, 1.25 inch BD needles available), makes frequent injections less of an issue. Warming the oil to body temperature helps with flow and viscosity as well. It is easier it inject 1cc of oil from a 1cc syringe than it is through a 3cc syringe. It's all about surface area and pressure. Ever try to push oil through a 60cc syringe? Your thumb exerts the same force regragless of the syringe, it's the surface area of the plunger that changes. Less surface area = more applied force to a given area of fluind to get it moving.



250mg every 2.5 days is also reasonable. The only small issue is to keep track of injections since one is injecting on a different day every time.

Mon AM
Wed PM
Sat AM
Mon PM
Thus AM.......

[Big D]

thats some great info BBB, thank you

[icey_boi]

what is the half life of injected winny? it must be longer than oral because it crystalizes in your muscle or somthing i think. i know it does something once its in you so that it takes hours to disolve dosnt it? i thought i read somthing like that once...?

[Dk]

what is the half life of injected winny? it must be longer than oral because it crystalizes in your muscle or somthing i think. i know it does something once its in you so that it takes hours to disolve dosnt it? i thought i read somthing like that once...?

tabs 9 hours.

depot 1 day

well according to that chart anyway.

[Blitz-Test]

Always inject in the PM, and to get your oil at body temp keep it in your ass crack for the day...

[icey_boi]

do you by chance know what the diff is in bio-availability? from tabs to injection? like how much of it actualy absorbed. eg.. say injection would be like 95% and pills are 82% or somthing.

[icey_boi]

Always inject in the PM, and to get your oil at body temp keep it in your ass crack for the day...

WTF....

[Dk]

do you by chance know what the diff is in bio-availability? from tabs to injection? like how much of it actualy absorbed. eg.. say injection would be like 95% and pills are 82% or somthing.

i always thought it was all the same. Since winny can be absorbed and survive through stomach acids i always just assumed it got into ya the same, whether injection or orally taken.

[Blitz-Test]

do you by chance know what the diff is in bio-availability? from tabs to injection? like how much of it actualy absorbed. eg.. say injection would be like 95% and pills are 82% or somthing.

heard something like

75mg injected is 100mg orally

[HoliTheCat]

Well **** me. Good to see this info again/still. Too many people still ride the once/twice a week injection train.


In theory take 75mg ED. Find a nice little 1cc tuberculin slip tip syringe (not an insulin rig) and the dosing will be easier, or take 150 EOD as it is likely more practical given this dosing scenario. [On the assumption that the steroid is concentrated at 250mg/ml] You'll only be slightly more than 500mg per week.

Obtaining parenteral oils that are of suffciently low viscosity to enable passage through a 25g needle or preferably a 27g (there are 27g, 1.25 inch BD needles available), makes frequent injections less of an issue. Warming the oil to body temperature helps with flow and viscosity as well. It is easier it inject 1cc of oil from a 1cc syringe than it is through a 3cc syringe. It's all about surface area and pressure. Ever try to push oil through a 60cc syringe? Your thumb exerts the same force regragless of the syringe, it's the surface area of the plunger that changes. Less surface area = more applied force to a given area of fluind to get it moving.



250mg every 2.5 days is also reasonable. The only small issue is to keep track of injections since one is injecting on a different day every time.

Mon AM
Wed PM
Sat AM
Mon PM
Thus AM.......