This is incorrect. Below is the full mathematical explanation of what happens with IM injection of AAS esters:
HALF-LIFE, ESTERS AND FRONT-LOADING
HALF-LIFE
When you inject AAS some of that gear will enter the bloodstream and some will be absorbed into your body fat (some may also crystallize at the injection site but that’s not important to this discussion). The portion that gets absorbed into your body fat will then slowly be released into your bloodstream over time.
The portion of the gear that gets absorbed into the body fat (and the rate at which it is re-released) is determined by its ratio of oil solubility to water solubility. The measure of this release rate is quantified as half-life. Half-life is defined as the time period at which half the compound has entered the blood and half still remains in the body fat.
Let’s take trenbolone acetate as an example. It has a half-life of 3 days, so if you were to take a single injection of 100 mg. After 3 days 50 mg would remain in your body fat. After 6 days 25 mg would remain; after 9 days 12.5 mg would remain, etc.
ESTERIFICATION
Most injectible gear has been esterified. The suffix “ate” at the end of the compound’s name indicates an ester. Testosterone enanthATE, trenbolone acetATE, nandrolone decoanATE are all examples. Esterification simply means that a hydrocarbon molecule has been attached to the steroid through an ester bond. In the case of testosterone enanthate, the enanthate ester has been attached to testosterone at the C17 atom.
Esterification is simply a method to control the time release of the steroid. The longer the ester attached to the base steroid, the more oil soluble it becomes and the longer its half-life will be.
Attaching an ester actually renders the steroid inactive. However, the bloodstream contains esterase enzymes that will break apart the ester bonds and return the steroid to its active form.
This mechanism is what causes many people on these boards to state that “test is test”. Neither test prop nor test enanthate, nor any other testosterone ester is active. The all get converted to free testosterone in the blood before they can activate any anabolic or androgenic receptors. However, many people will report that they get fewer side effects from test prop that test enanthate, etc. If this is true it must be due to some less understood mechanism.
FRONT-LOADING
Let’s go back to our example of trenbolone acetate. Let’s say you decide to dose 150 mg of tren every 3 days for an average dosage of 50 mg/day. On day 1 you inject the 150 mg. Three days later, 75 mg is still stored in your body fat so your average dose was only 25 mg/day. After your next injection, the 150 mg is added to the 75 mg already stored, so 225 mg will be in your body and you will absorb 112.5 mg over the next 3 days for an average dosage of 37.5 mg/day.
With each successive injection, the amount of tren in your body approaches 300 mg at which point you will reach equilibrium and the full 150 mg you inject will be absorbed into your bloodstream in 3 days.
This gradual buildup of gear in your body fat is why it takes some time for injectible AAS to “kick in” (especially long half-life AAS).
But suppose you inject 300 mg of tren on day 1? In this case you will start out absorbing 150 mg in 3 days and you will be at equilibrium from day 1. This is the concept of front loading.
However, it gets a little more complicated. Suppose you wanted to dose 400 mg/week of deca. With its half-life of about 14 days you’re taking in 800 mg over a one half-life period so you’d have to inject 1.6 grams on day 1 to start out at equilibrium.
I don’t know about you, but I’m not injecting that much of any gear all at once, regardless of the half-life. Here’s why:
Published half-lives are based on the effect on the average population (in many cases they’re calculated and not actually measured). Some people have faster metabolisms than others so in some people the half-life will be shorter, in others it will be longer. Besides, AAS are taken by athletes; it is known that an intense workout can speed-up your metabolism for up to 48 hours afterward. Therefore, you should expect that the half-life will be shorter for you than for the average person. All this adds up to too much margin for error to inject such a ridiculously high dosage.
Here’s another complication; injecting gear at a frequency equal to its half-life will result in +/- 25% swings in blood level for that compound. In our example above dosing 300 mg of trenbolone acetate on day 1; your bloodstream would actually see about 62 mg of tren on day 1, 49 mg on day 2, and 39 mg on day 3…not quite a steady 50 mg/day.
To even out blood absorption levels, dosing more frequently is recommended. In the deca example above I mentioned dosing 400 mg/wk. Injecting at a frequency of ½ the half-life like this will result in blood levels remaining within +/- 16%. Also, doubling the dosage for the first 2 injections (800 mg) in this case will bring you to equilibrium at the 2nd injection (one week’s time) and results in a much more comfortable dosage range.
Similarly, injecting a compound at a frequency of 1/3 its half-life will keep blood levels at +/- 9%. In this case you front-load by doubling the dosage of the first 3 injections and you will be at equilibrium by the 3rd injection. At ¼ the half-life you’d double the dosage for the first 4 injections, etc.