Half-life

**chaos_theory** · 01-23-2007, 02:20 PM

Could somebody please give me a detailed explanation of how you can effectively work out the half-life of an ester, there is just too much conflicting information. Here is an example:
.................................Formula........M. Weight.....Half-Life
Propionic Acid............C3H6O2.............74............. 3 days
Phenylpropionic Acid...C9H10O2..........150...........5 days?
Isocaproic Acid............C6H12O2.........116..............?
Cypionic Acid...............C8H14O2.........132.........16 days
Enanthoic Acid.............C7H12O...........130.........15 days

I can't understand why the half-life of Phenylpropionic Acid would be so close to Propionic Acid when the molecular weight is double the amount, also it has 3 times the amount of carbon atoms.

Is my thinking incorrect is neither the molecular weight or carbon atoms used when calculating the half-life, could somebody please enlighten me on this subject.

**chaos_theory** · 01-23-2007, 03:26 PM

..bump..

**mkrulic** · 01-23-2007, 03:49 PM

I think there are more chemists in the anabolic lab section. good q tho

**chaos_theory** · 01-24-2007, 02:52 PM

Originally Posted by mkrulic

I think there are more chemists in the anabolic lab section. good q tho

Thanks for the heads up I might try my post in that section

**tranzit** · 01-24-2007, 02:58 PM

Half life of drugs in the world of steroids is a funny conversation. Alot of people worry about the half life of sust or somthing like that.. its rediculas becouse all of the esters in that compound have diffrent half lifes. So your going to shoot sust twice a day becouse it has prop in it to keep the blood levels stable... ohh but wait.. the decconate can last what 15 days... before it fades. So make sure your not worrying about drugs that are rediculas to try and keep stable. As all your doing is throwing your money down the drain.
*DISSCLAIMER* I am not saying that half life and stable blood levels are not important but just not in everything you take.

**armbar83** · 01-24-2007, 04:25 PM

ive had organic chem so ill take a shot. even though phenylprop has alot more carbons, its still prop with a phenyl group attached. all the extra carbons/hydrogens/weight are wrapped up in the side chain phenyl group so the chain is not as long as it should be for its weight. i dont know but i would assume that isocap has a much shorter half life than enanthate for this same reason. the isogroup doesnt add to the length of the chain, it branches off. im not looking at a book or anything, just assuming from general chem knowledge.

**armbar83** · 01-24-2007, 04:28 PM

i dont know that you can effectively "work it out" its alot more complex than the number of carbons and what it weighs. the isomerism, functional groups, side chains, ect. all play a role in its half life.

**chaos_theory** · 01-25-2007, 06:05 PM

Originally Posted by armbar83

ive had organic chem so ill take a shot. even though phenylprop has alot more carbons, its still prop with a phenyl group attached. all the extra carbons/hydrogens/weight are wrapped up in the side chain phenyl group so the chain is not as long as it should be for its weight. i dont know but i would assume that isocap has a much shorter half life than enanthate for this same reason. the isogroup doesnt add to the length of the chain, it branches off. im not looking at a book or anything, just assuming from general chem knowledge.

Thanks for the informative reply, nice to see an educated guess with a logical reason.