Anyone new to steroids may be wondering what Steroid half life means, even some experienced steroid users may also be wondering what half-lives means. So here in simple terms you can read and hopefully understand all about steroid half life’s and what this term means.
Basically every drug has a half life, steroids included. If for example, you were to inject 1000mg of testosterone cypionate once weekly, for 10 weeks, how would you know when you were “off”? Would you be “off” when you had finished your last dose? You would be able to calculate this from the half life of testosterone cypionate. The half life of testosterone cypionate is around 12 days. This means that 12 days from your last shot of 1000mg of testosterone cypionate (Time to start PCT? You decide.), your blood levels of testosterone cypionate will contain 500mg of the steroid. Another 12 days from then, i.e. 24 days from last dose, your blood levels will contain 250mg of the steroid. This amount then keeps halving every 12 days. At 48 days (almost 2 months) from your last dose, your blood levels will still contain 67.5mg of testosterone cypionate.
Therefore you can clearly see that when you finish your cycle, even though you are not putting any steroids into your body, you may think that you are now “off”, however you still have, and will still have for some time after your last dose, “active” blood levels of the steroid. Therefore you can plan what to use, how long for, and how long off your cycle, based on these half life’s.
Below a list of 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
Winstrol (stanozolol) (tablets or depot taken orally) 9 hours
Depot steroids Drug Active half-life
Deca-durabolin (Nandrolone decanate) 14 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 2 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
T3 10 hours
Active Life versus Half Life
The confusion comes from the 2 terms being used synonymously when they should not be. “Half-life is not a reference for the total time a drug will be found active in the body. It may take several half-lives before the drug is completely inactive.”
Half-life: The period of time required for the concentration or amount of drug in the body to be reduced to exactly one-half of a given concentration or amount.
Example: The half-life of anavar is 9 hours+/- (9 hours after oral administration of 50 mg of anavar, 25mg is still present in the body).
Active life: Refers to the period in which the amount of a drug in the body is enough that it will still produce the desired effects for which it was administered. Or conversely, inhibit natural recovery of normal bodily function. It is dose dependent.
Example: The active life of 1,000mg of testosterone decanoate would be more than one month. At day 30 after injection, 250mg or more of this drug would still be present in the body.