Presser

Admin
Staff member
Administrator
Moderator
MuscleChemistry.com Pharmacokinetics

I will Explain how the half-life of a drug works and then list the various SERM's used During Post Steroid Cycle Therpay and eaches Half-Life For our MuscleChemistry members who arent all too familiar with how this works, so they can better understand what dosage is best and more importantly when to take certain PCT meds whether that is Daily (ED aka Every Day) Or Every Other Day (EOD). Understanding Peak Plasma Concentrations and Rates of Elimination Is Important!

All of this can be translated the same for other drugs, Steroids, or medicines! I just think PCT Post Steroid Cycle Therpay Drug Coverage Is Most Important, more so than the hormones used in your actual steroid cycles, as what good are all those gains made if you arent smart enough to keep them, or what good was that steroid cycle if afterwards you find that you have physical health issues, permenant shut down of exogenous testosterone, or estrogen related side effects causing acne, mood swings, and unwanted breast tissue.

In days to come I will also try covering the following:

Absorbtion Rates

Bioavailability

Clearance



HALF-LIFE Translation : "Time it takes for the plasma concentration or the amount of drug in the body to be reduced by 50%."

Half-Life Delineation, Explanation, Translation, and Interpretation For My Brothers of
MuscleChemistry Nation!

Y.T. Presser


By definition, the plasma concentration of a drug is halved after one elimination half-life. Therefore, in each succeeding half-life, less drug is eliminated. After one half-life the amount of drug remaining in the body is 50% after two half-lives 25%, etc. After 4 half-lives the amount of drug (6.25%) is considered to be negligible regarding its therapeutic effects.

The half-life of a drug depends on its clearance and volume of distribution. The elimination half-life is considered to be independent of the amount of drug in the body.

Clinical implications

Half-life determines the length of the drug effect.

It also indicates whether accumulation of the drug will occur under a multiple dosage regimen and it is essential to decide on the appropriate dosing interval.

Related termsElimination rate constant (λ): Fractional rate of drug removal from the body. This rate is constant in first-order kinetics and is independent of drug concentration in the body. λ is the slope of the plasma concentration-time line (on a logarithmic y scale).

Apparent half-life (t1/2):

In some cases, such as for controlled-release preparations, the rate of decline of the drug plasma concentration is not due to elimination alone. Other factors such as absorption rate or distribution rate influence plasma concentration decay.

In such conditions, the observed half-life is called apparent half-life.

Assessment

ad0d2687c5e6359a8cfa80def172a057.png

Vd = volume of distribution
CL = clearance
λ = elimination rate constant = CL/Vd
 
Last edited:
So what PCT drug would anyone like to start out with?

Nolvadex aka Tamoxifen comes to mind and is also the reason behind this in the first place due to the confusion over why or how is it you have ben taught that nolvadex should be taken daily when its half-life is listed at 5 days. (Yes I know some lists have it at 5-7) but for our (bodybuilders) reason for its use, it better to use the shorter half-life.

I am also good with anyone else here who wants to jump in and help run these SERM half-lifes down for our Members
 
Back
Top