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.
author unknown
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.
author unknown