Active Half-Life of Steroids

[RonnyT]

To explain in short:
in the chart approx. 20 days
testosterone undecanoate in tea seed oil had a half life of 21 days
testosterone undecanoate in castor oil had a half life of 34 days

This study was done in respect to MENT. They want means that stay stable for a long time and injection intervals as long as possible. Thats also why long ago Sustanon was created for hormone replacement.

[RonnyT]

Not to want to know better but completely unscientific. You can find these charts all over the net. It could be true, providing all these active ingredients where compounded in the same oil -solvents - co-solvents -preservatives. Look at this study and I have many more a university in Sweden does very good research to optimal carriers/pharmacokenetics/drugdelivery

Objective:
In the search for long-acting testosterone preparations suited for substitution therapy of hypogonadal men, testosterone undecanoate (TU) dissolved in either tea seed oil or castor oil was investigated.
Design:
* In study I, 1000 mg TU in tea seed oil (125 mg/ml) were injected in equal parts into the gluteal muscles of seven hypogonadal men.
* In study II, 1000mg TU in castor oil (250 mg/ml) were injected
into one gluteal muscle of 14 patients.
Results:
In comparison with published data on testosterone enanthate, most widely used for i.m. injections, the kinetic profiles of both TU preparations showed extended half-lives and serum levels not exceeding the upper limit of normal.
The TU-castor oil preparation had a longer half-life than TU in tea
seed oil 34 vs 21 days
European Journal of Endocrinology 140 414–419

[goanywhere]

Very useful info.

I agree - and interesting.

[sixteentons]

Very useful info.

[dr.Stack]

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
Steroid esters

The half-life applies to the ester regardless of hormone attached, for example trenbolone enanthate and primobolan (methenolone enanthate) will act very similarly to testosterone enanthate in terms of release rate.

Drug Active half-life

Suspension within 1 hour
Acetate 1 day
Propionate 1 day
Phenylpropionate 1-2 days
Butyrate 2-3 days
Valerate 3 days
Hexanoate 3 days
Caproate 4-5 days
Isocaproate 4-5 days
Heptanoate 5-6 days
Enanthate 5-6 days
Octanoate 6-7 days
Cypionate 6-7 days
Nonanoate 7 days
Decanoate 7-8 days
Undeclenate 8-9 days
Undecanoate Approx 20 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