Steroid Half Lives, Formulas, Confused...

[SomeRandomGuy]

So most places you'll check will show you the half life table for steroids. But from these numbers you can't know what the level of active mg in your body is at any given day.

I read this:

Now let's get to the interesting part. How to easily calculate blood levels of most any drug. First take a look at the formula used. The first is D-(D)(1/2)^((T-DT)/H). This calculates blood levels before the half-life. To calculate the half-life and after, the following formula is used (D)(1/2)^((T-DT)/H). The variables used are as follows:

D - Dosage in milligrams

T - The day you want to know the blood levels for

DT - The day the drug was taken

H - The Half life in days



For more precision, DT and H could be multiplied by 24, which would give you hourly levels instead of daily levels. T would become hours instead of days. Here is how you'd use them; first let's look at the day after a 200mg injection of Testosterone Propionate.

200 - (200)(1/2)^((2-1)/3.5)

= 200 - (200)(1/2)^1/3.5

= 200 - (200)(0.820)

= 200 - 164

= 36



Now let's look at the fifth day after the injection.

(200)(1/2)^((5-1)/3.5)

= (200)(1/2)^4/3.5

= (200)(0.453)

= 90.6

Here's me trying out an 500mg Enanthate Ester injection with the formula:

500 - (500)(1/2)^((2-1)/10.5)

500 - (500)(1/2)^1/10.5

500 - (500)(0.5167)

500 - 258.35

= 241.65mg 1 day


500 - (500)(1/2)^((7-1)/10.5)

500 - (500)(1/2)^6/10.5

500 - (500)(0.6720)

500 - 336

= 164mg 6 days


So at the drug's half life and beyond you don't need to subtract D right?


(500)(1/2)^((10.5-1)/10.5)

(500)(1/2)^9.5/10.5

(500)(0.5341)

267

= 233mg 10.5 days ?!


Now I went through step by step and checked the guy who wrote this formula's equations, and they seem to work. They even make sense. Why don't mine? Did I do the formula wrong, or does it just not work?

He goes on in the thread to reference roidcalc.com, which he says you can use if you have a problem with formulas, etc...

If you put info into roidcalc.com, it will not give you numbers remotely close to the numbers obtained by these formulas.

Just for example, I put in 200mg in the field under "Virormone/
Testovis/
Testopin", that's Propionate.

Let's recall what he had for Day 2 and Day 5 (36mg & 90.6mg).

Well when I punch 'Calculate', I get:
Day 2 I get 39mg. (OK so this one is close, 36-39...) On day 5 I get 14mg.

If you uncheck the box that says 'View active mg/day' you get:
Day 2: 134mg, Day 5: 48mg.

What do they mean by active and (I assume inactive) mg/day of AAS? Some is active and the rest is still deposited in your glute?

Lolz, on a sidenote I found that if you want to frontload Deca Durabolin (using roidcalc), just click on View Active mg/Day, then type 5000mg into the Deca field. You're starting out on Day 1 with 448mg and it tapers down slowly from there. So if you want to have an instant 400mg Deca, just shoot 5g of it in one shot.

Anyhow, the numbers don't match up, and it all adds up to a whole bunch of I have no f'n clue.

Anyone in the light on this? I'd like to know what the active mg of steroid was at any given day. If you could point me to a thread that'd be ok too.

[zoltans4]

i can't answer your question directly because your post was a bit hard to follow on what was his and what was yours and where you are going wrong, but I do know pharmacology.
I can tell you that is doesn't really matter that much and will be wrong because a day is 24 hours and there is alot of fluctuation going on.
Biomedically we are interested in blood levels sustained on an AVERAGE to get therapeutic results. This is WHY half lives exist and give the basis for when you dose. all of these are affected by the ADME scheme which can also change person to person and therefore why dosages are person dependant and start low and work up.
Honestly it is easier if you simply take out some graph paper and put time on the bottom and blood levels on the side. Your graph will then look like a stock exchange as it goes up and down as levels peak (but continues up at the begining) then sorta roller coasters while you stay on your dose. This graph is simple and can be done with the half lives and without crazy math.
if your obsessed with the math, please clarify where your problem is so i can look closer.

[SomeRandomGuy]

i can't answer your question directly because your post was a bit hard to follow on what was his and what was yours and where you are going wrong, but I do know pharmacology.
I can tell you that is doesn't really matter that much and will be wrong because a day is 24 hours and there is alot of fluctuation going on.
Biomedically we are interested in blood levels sustained on an AVERAGE to get therapeutic results. This is WHY half lives exist and give the basis for when you dose. all of these are affected by the ADME scheme which can also change person to person and therefore why dosages are person dependant and start low and work up.
Honestly it is easier if you simply take out some graph paper and put time on the bottom and blood levels on the side. Your graph will then look like a stock exchange as it goes up and down as levels peak (but continues up at the begining) then sorta roller coasters while you stay on your dose. This graph is simple and can be done with the half lives and without crazy math.
if your obsessed with the math, please clarify where your problem is so i can look closer.

I fixed the quote so you can see what was his and what was mine above. How would you go about creating a graph of blood levels/active mg if you can't generate the data for it somehow? The results I got from trying out the 500mg Enanthate don't seem to jive. First it goes down, then back up at day 10.5? It's a pretty simple equation, I don't think I did it wrong. Shouldn't you have half of the initial dose in mg left on the aas' half life day? Meaning if I take 500mg Enanthate, and my half life is 10.5 days, then I'd have 250 halfway through day 10. And it was my understanding that the mg tapered up till the half life day?

Thx for the input, I remember my endocrinologist saying something about test levels fluxuating daily. Seems like if you have an injection in you, though, wouldn't that mean it's more sustained than your own natural test?

[zoltans4]

well, i am defiantly more versed in orals than injections. But if you have a 10.5 day half life you would theoretically have 250mg left over from the initial 500, but depending on how your body processes (this is where these esters can be doing something else im not aware of, we didn't learn steroids in school, lol) the peak blood levels should be closer to about 5 days.

[SomeRandomGuy]

well, i am defiantly more versed in orals than injections. But if you have a 10.5 day half life you would theoretically have 250mg left over from the initial 500, but depending on how your body processes (this is where these esters can be doing something else im not aware of, we didn't learn steroids in school, lol) the peak blood levels should be closer to about 5 days.

Makes you wonder why it takes 4-5 weeks for long chain esters to kick in. Seems like there'd be enough to see something sooner than that.

Another related question; if you want to frontload a regimen of 500mg/wk test, you'd use 1g the first injection, right? Well let's say that your dose is 250mg/ml and you don't want to shoot 4ml at once. Could you go 500mg 2x for that first week, then go 250mgx2 thereafter? See that's why I want to know the formula so I can build graphs in excel, etc...

[zoltans4]

your math here seems incorrect:

Here's me trying out an 500mg Enanthate Ester injection with the formula:

500 - (500)(1/2)^((2-1)/10.5)

500 - (500)(1/2)^1/10.5

500 - (500)(0.5167) I get like .936 here

500 - 258.35

= 241.65mg 1 day therefore my answer is 31.9 or something

it is 3am, double check me that I double checked you.

[zoltans4]

Makes you wonder why it takes 4-5 weeks for long chain esters to kick in. Seems like there'd be enough to see something sooner than that.

Another related question; if you want to frontload a regimen of 500mg/wk test, you'd use 1g the first injection, right? Well let's say that your dose is 250mg/ml and you don't want to shoot 4ml at once. Could you go 500mg 2x for that first week, then go 250mgx2 thereafter? See that's why I want to know the formula so I can build graphs in excel, etc...

check my math.
after you do all of this math, and load into exel (which i would like to see, cool idea) you will see what I meant about guesstamating averages and plotting it on graph paper, its easier than the math makes it seem.

[zoltans4]

more importantly how is it you are going to put this into exel through the weeks?
you have to do almost 52 days of math per cycle and add the next cycle on top of your numbers. it takes 5 half lives for a drug considered 0 or not doing anything

so
week 1
injection1
day
1 2 3 4 5 6 7 8 9 10 11 12 13 14........
injection 2
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18......

this is a big stack that will add up with these long esters. for the rest of the population we could care less and rely on theory. if you want to be mathmatical about it, you have alot of work to do it CORRECT. you could half ass it, but thats alot of work to have something tell you what you could do in your head reallly

[SomeRandomGuy]

more importantly how is it you are going to put this into exel through the weeks?
you have to do almost 52 days of math per cycle and add the next cycle on top of your numbers. it takes 5 half lives for a drug considered 0 or not doing anything

so
week 1
injection1
day
1 2 3 4 5 6 7 8 9 10 11 12 13 14........
injection 2
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18......

this is a big stack that will add up with these long esters. for the rest of the population we could care less and rely on theory. if you want to be mathmatical about it, you have alot of work to do it CORRECT. you could half ass it, but thats alot of work to have something tell you what you could do in your head reallly

Yeah, eventually you get overlap with multiple injections. If you could know formulaically what the active blood level mg of steroid was on any given day, however, I think even the overlap wouldn't be an issue. You'd just calculate for each injection seperately, then add the decaying half life of the previous injection. Problem is, anywhere you go online, they only care about what the drug is at it's half life day. How much is active in between? Which also makes me not understand why it takes so long for the effect (increased protein synthesis) to occur, (4-5 weeks). I guess noone cares, so I'll have to keep searching.

[zoltans4]

its because of long lasting esters and breakdown for longer life. Remember this stuff isn't made for body builders it is TRT and made for people to inject less. Things like that are big business in the pharma industry. It was probably a big money maker when a long laster ester first hit for TRT....
longer to breakdown, longer to increase blood levels but over time able to keep stable blood levels. less doctor appointments for him to shoot you - save money.

so as you can see it takes about 20 days for a full 500mg to start averaging in the blood or so, then over that week of those levels with high test you start getting gains and feeling it, theres your 4 weeks.