Calculating Half Life


Getting ripped
Does anyone have a formula used to calculate the total amount of steroid esters in the blood after X weeks of injections?
Calculating is easy.

The hard part would probably be deciding the half-life of anything as it always seems to be very debatable.
Well lets take Deca for an example. Lets give it a half life of 15 days. If I want to calculate how much that has "left the system" in 1 week. And I would have shot 200mg the week before. Would the calculation be as follows??:

200/2=100mg in 15 days
100/15=6, per day
6,66..*7=46,66mg.. after 7 days
My point it actually possible to calculate the amount Deca leaving the system per day OR does it have to be per every 15 days??
Those roid calculators calculate the theoretical amount of Anabolic Androgenic Steroids (AAS) de-esterifed, not plasma Anabolic Androgenic Steroids (AAS) levels.

BTW, the half life of Deca is about 6 days.
6 days?
I don't really know what to believe about steroids half life. Everyone says differently.
I used to think it's 15 days also, don't trust those profiles & half life lists...

Acta Endocrinol Suppl (Copenh) 1985;271:19-30 Related Articles, Links

Pharmacokinetic parameters of nandrolone (19-nortestosterone) after intramuscular administration of nandrolone decanoate (Deca-Durabolin) to healthy volunteers.

Wijnand HP, Bosch AM, Donker CW.

Nandrolone decanoate (Deca-Durabolin) was injected intramuscularly into healthy volunteers. One group of females received one injection of 100 mg and three groups of males received one injection of 200 mg, two repeat injections of 100 mg or four repeat injections of 50 mg respectively. The serum levels of nandrolone (19-nortestosterone) were determined by radioimmunoassay and used to estimate pharmacokinetic parameters. The following pharmacokinetic parameters were found: a mean half-life of 6 days for the release of the ester from the muscular injection depot into the general circulation; a mean half-life of 4.3 h for the combined processes of hydrolysis of nandrolone decanoate and of distribution and elimination of nandrolone; a mean nandrolone serum clearance of 1.55 1 X h-1 X kg-1. The half-life of hydrolysis of nandrolone decanoate in serum was of the order of one hour or less. The data are consistent with linear kinetics.
half-life is going to change on a number of factors:

where's the injection?

differences in oil used.

initial dosage amount (increasing dosage will delay the initial peak which then delays the half-life)