Active Half-life of Steroids and Esters


1.What is steroid half life?

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.
Half-life is 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.
For example:
When 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.


2.A list of half-life’s of the most commonly used steroids, esters and ancillary compounds.

Oral steroids Drug Active half-life:

Anadrol (oxymetholone):8-9 hours

Anavar (oxandrolone):9 hours

Dianabol (methandrostenolone, methandienone):4.5-6 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

trenbolone acetate:3 days

Primobolan (methenolone enanthate):10.5 days

Sustanon: 15-18 days

Testosterone Cypionate:10-12 days

Testosterone Enanthate:7-10.5 days

Testosterone Propionate:4.5 days

Testosterone Suspension:1 day

Winstrol, injectable (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