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by , 03-17-2010 at 04:32 AM (883 Views)
The definition of half-life in regards to biology and pharmacology is simply the time required by the body, tissue, or organ to metabolize or inactivate half the amount of a substance taken in (Taber’s Cyclopedic Medical Dictionary). These principles are used for all medications, not just AAS. I’m going to break this down to the simplest form I can so bare with me because it may get a little confusing.

The key thing to remember when it comes to half-life’s is that they will always be reduced by half of what’s remaining on a proportional and timely basis.

I’m going to use Testosterone Cypionate as my example in this demonstration since it is a commonly used AAS for beginners and pros alike.
Testosterone Cypionate half-life is 8 days

500mg Test Cyp every 8 days
Day 1 – 500mg (remember that the bioavailability at this point is 0 because it takes 8 days to metabolize 250mg, and this will be true for every dose that follows)

Day 9 – 500mg (remember what was stated on day 1), so at this point you have 250mg remaining in the body from day 1 because your body has used 250mg over the past 8 days)

Day 17 – 500mg, at this point you have 250 from Day 9 and 125 from day 1 (don’t confuse yourself here, the body does not process 250mg every 8 days, it simply reduces the remaining by half every 8 days)

Day 25 – 500mg, at this point you have 250mg from Day 17, 125 from Day 9, and now just 62.5 remaining from day 1

Day 33 – 500mg, at this point you have 250mg from Day 25, 125 from Day 17, 62.5 from Day 9, and 31.7 from day 1.

The easy way to keep going on with this formula is to take the smallest number (31.7 in this case) and reduce it by half, then add it to your existing numbers for the total, and then repeat.

The total looks like this:
The first 8 days your body will metabolize 250mg
The second 8 days your body will metabolize half of the remaining 250 (125) and half of the 500 (250) administered on day 9 for a total of 375.
The third 8 days your body will metabolize 250, 125, and 62.5 for a total of 437.5. This is one reason it takes a couple of weeks to start noticing the effects of this drug.
To keep figuring out the bioavailability just keep reducing your smallest number by half and adding it to the total as described earlier.

Here is a chart demonstrating the bioavailability and how long it takes to even reach that 500mg per 8 day mark. For this demonstration we will use 8 days for 1 wk.
Wk 1 – 250mg
Wk 2 – 375mg
Wk 3 – 437.5mg
Wk 4 – 469.2mg
Wk 5 – 485mg
Wk 6 – 492.9mg
Wk 7 – 496.8mg
Wk 8 – 498.7mg
And so on….

So what does all this mean? Well for one it brings up a very important issue of frontloading. To frontload, you simply double your weekly dose just for that first week. It would look like this:
Wk 1 – 1000mg Cyp
Wk 2 – 500mg Cyp
Wk 3 – 500mg Cyp
And continue on at the normal 500mg/wk

The way this works is simple, during week 1 your body will metabolize 500mg of the first dose leaving you with 500 remaining. The second week your body will metabolize 250mg from the first dose and also 250 from the second dose for a total of 500. Now do you see how beneficial frontloading really is? You will stay constant at 500mg/wk throughout your cycle instead of tapering up by not frontloading.

All that has been described in this post is hypothetically based on the principles of half-life’s. Nevertheless, this should give you a general idea of how much your body is using in any one given week. This holds true for every AAS and medication there is, after all that’s what medication administration is based on so don’t argue with me about this, argue with science and the millions of doctors who actually get paid to come up with this stuff.

Also, on a side note, I’ve noticed quite a few boards that vary on half-lifes for certain AAS such as Cyp, most state the half-life as being around 10 days. I’m in no way saying this is wrong but I tend to get and base as much information as possible on medical articles and websites. I have found the half-life of cyp to be 8 days both in a nursing book and also on drug.com. The only catch to this is that some, in fact most AAS are not evaluated, published, or even talked about in the medical field so your on your own on that one.

This text is a re-written version of frontloading written by THE BIG 1, it in no way infringes copyright.
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