Active Half-life of Steroids and Esters

[FUZO]

TweetActive 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.

This article covers the half-life's of the most commonly used steroids, esters and ancillary compounds.

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


*Winstrol depot does not actually possess a classical half-life because it is un-esterified. Instead, the microcrystals dissolve slowly. Once they have all dissolved levels of the drug fall very rapidly. It is still an important consideration, and we have included it with a half-life of one 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.

[Double]

Tweetgood post. some of those are hard to find out from older books regarding AAS

[JohnnyB]

TweetThose are being posted every where but they are not the half-life what I don't understand is the "active half-life" is it the active life or the half life. the half-lives I alway seen are shorted then those.

JohnnyB

[HungarianBeast]

TweetHmmm...sound like a good subject to do a little researh on.... Thanks JB.

Those are being posted every where but they are not the half-life what I don't understand is the "active half-life" is it the active life or the half life. the half-lives I alway seen are shorted then those.

JohnnyB

[JohnnyB]

TweetIf you hit the drug profiles in my sig you'll see the active life is the same as these that are listed as half-life. I'd be willing to bet these originally came from Mick Hart out of the UK.

JohnnyB

[pigmeat]

TweetJohnnyB is right...

[firstenrgy]

TweetIt seems year after year the half-life of the esthers get longer and longer. How is this? 4 years ago the posted half-life on the boards for cyp was 5-6 days. I've always taken the info as fact and the only one I looked up was Winstrol. It had a 48 hour half-life in animals when injected. It was an Upjohn study.
firstenrgy

[pigmeat]

Tweet

It seems year after year the half-life of the esthers get longer and longer. How is this? 4 years ago the posted half-life on the boards for cyp was 5-6 days. I've always taken the info as fact and the only one I looked up was Winstrol. It had a 48 hour half-life in animals when injected. It was an Upjohn study.
firstenrgy

You must not have read Johnnyb's response.....Those are the ACTIVE LIFE......which would make you correct...cyp active life=12 days, which makes the HALF LIFE 5-6 days.

Somewhere in the past someone on the boards got the two confused, and it has been taken as gospel by some.

[JohnnyB]

Tweet

It seems year after year the half-life of the esthers get longer and longer. How is this? 4 years ago the posted half-life on the boards for cyp was 5-6 days. I've always taken the info as fact and the only one I looked up was Winstrol. It had a 48 hour half-life in animals when injected. It was an Upjohn study.
firstenrgy

That is the half-life of cyp, the bros in the UK are the ones doing the changing of the half-lifes, but if you notice he doesn't call them "half-life" he calls then "active half-life", which is porbably his way of saying active life. They do say things different over there.

Okay after doing a little bit more reading while typing this post I realized that these "active half-lifes" are in the middle of the half-life and the active-life, that why they are called "active half-life", so they're not the half-life or the active-life, they're the active half-life.

Damn why do people have to make things more confusing then they already are?

JohnnyB

[firstenrgy]

TweetAhhhh, thanks for the heads up bro's
firstenrgy

[HungarianBeast]

Tweet

Damn why do people have to make things more confusing then they already are?

JohnnyB

I agree!

So, do you have a table of actual half lives. I need them for a spreadsheet I built.

[Tux]

TweetHere's one I've never been able to find. Hexahydrobenzylcarbonate. The ester attached to the old parabolan. I've heard it's shorter than enth but fairly close. Anyone know the active or half-life of para?