T Nation

Thyroid Optimization W/T4


Hi to all,
i have free access to a nice quantities of T4...
so i would like to use it to optimize my metabolism

i have read on AR book intrestinf stuff, but yet i have no clear idea of which kind of cycle set up...
my target is to reduce drastically body fat...( i would like to lose about 10kg of fat.. ) offcourse i m dieting
any experience to share?


I would suggest against using T4, and instead suggest using T3. T4 can be referred to as the inactive form of T3. T3 is the active thyroid hormone that will elicit metabolism changes.
T4 is converted to T3 via the 5'-deiodinase enzyme and the process is slow, with the half life of T4 being about one week. T3 has a half life of about a day. So the use of T4 is hard to control, as it will take longer for the effects to take place, it will take longer for your body to normalize once you cease taking the drug, and you will have to take a larger dose of T4 as opposed to T3.

Also, (and I don't know this for sure), but I think you will also have to increase the dose of T4 as you progress through the cycle because the thyroid feedback loop will limit the amount of T4 that can be converted to T3.

Besides that side information, I have no suggestions on how to use T4 because I have never used it, and won't use it. I have used (and only will use) T3.


i know.. but.. well T4 is free... so by now i would like to use it cause it so cheap (well it' s free...)

how much larger? i have read of rate of 1/4... is this true?

and about half-life... T4 has a longer one so it is not just the case to consider that time in the tapering down phase?

i would to use t3 too.. but by now it is harder to find for me.. instead i have very large amount of free t4...


Your metablosim is optimized through thousands of millions of years of evolution.

If you're going to mess with it.. take it real slow and increase gradually.

Don't fuck with the thyroid too much.


ok, mom :wink:


If you start taking exogenous thyroid hormone, then endogenous production will stop. Basically taking T4 will suppress your bodies natural production.

Thyroid balance is a tricky topic. The thryroid gland is very complex and has many functions in the body, not just metabolism. Disrupting a normal thyroid's function is not a good idea.

The very fact that you're posting on a web forum means that you shouldn't be messing with T4.

If you want to increase your metabolism and fat loss, then get your fat ass off to the gym.


ok, i know that.
but as read in AR book and other resources that "suppression" is often over-rated...

by that point of view neitheir messig with IGF, testo and so on is a good idea....

qhat i mean is that every therapy is a breack of a natural equilibrium...

which are the need of a forum if it is not possible to ask?

really.. i dont understand.

i have read many books, i have done personal research, talked to other ppl.. than i have thought to ask here, where i know there are many experienced guy...

i workout quite every day, i'm eating clean and i'm doing all the hard job... i think i have reached nice goal with my training and just want to improve faster. where is the problem?

i'm not the classic stupid american fat teen posting here to find the magic to be lean for the beach :slightly_smiling:

other than that i need to lose weight a bit faster to be in weight category to compete (not as bber or pler)


I love how no one with experience with either T3 or T4 helps out. Someone who has used T4 should help, unless no one has.
Like I said, I have only used T3, but I will try to help with your T4 use.
It it seems that T4 will max out at 300mcg/day. I would probably taper up to 300mcg and then taper down. Maybe something like this for a 6-week plan(but remember that I don't know what I am talking about):

Days 1,2: 60mcgs
Days 3,4: 120mcgs
Days 5-11: 240mcgs
Days 11-16 : 300mcgs
Days 17-19: 225mcgs
Days 20-22: 150mcgs
Days 23-28 : 120mcgs
Days 29-33 : 75 mcgs
Days 34-42 : 37.5mcgs

This gives a long and slow taper down, which might be best given the 7-11 day half life of T4.

Something else to think about:
"There have been a number of studies that have shown that during reduced caloric intake, and/or when carbohydrate intake is reduced dramatically, levels of deiodinase decline, hindering the conversion of T4 to the physiologically active T3(1). So, if you are dieting (which would necessarily mean you have a reduced caloric intake and/or reduced carbohydrate levels), then you have less deiodinase enzyme (still with me?) and thus, that T4 you are taking in hopes of getting it to convert to T3, is not getting converted."-Anthony Roberts

So my advice to you: I don't care if it is free, don't use it. I have been given free T4 before, and I didn't use it. If I am going to screw around with my thyroid, I am going to make sure that I get results (using T3). And that can't be gauranteed with T4.


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thx guys i'll make my research and experience than i'll post the results.. :slight_smile:


Note that my advice doesn't apply if you are using GH with thyroid meds. You need to use T4 and Not T3 if you want an enhanced anabolic effect from GH. T3 will stunt the anabolic effect of GH, though not it's fat-burning ability.


hi to all,
just a little "update" to my results.
by now i am at the second week at 300mcg.
i have no side effects, i have no losing in muscle mass, no reduced performance.

and i have lost about 3kg (a bit less..) largely in the current week.

T4 is working really good for me, and i'm just thinking to the "future" plan for a chem enancement of cadav :stuck_out_tongue:


I would just like to add that nobody really has thought of the risks of combining these powerfull hormones related to cellular aging, and the developement/ changing of any malignancies/or benign tumors you may have lurking somewhere in your body that you don't know about yet.

It seems like a lot to risk.


i really don't bother about aging effects..
and for tumors related risk, well also AAS and HGH can be a dangerous addon to a critical lurking situation...

a lot of problems "may" arise from drugs "body enhancement". Also a lot of problem "may" arise from the simplest workout...


Yea, you tell that song and dance to the 44 y.o. guy who just sat in Emerge all day last week with hemoptosis, with his loving family, only to find out at the end of the day he's got lung cancer. -He's wishing he didn't smoke a pack and a half a day for 30 years now. The whole, 'I could get struck as I walked across the street at anytime argument... so therefore I'll eat drink and be merry" doesn't wash once reality kisses you in the ass!


Oh to be young and immortal...


You need to do some research.

Nobody has "really thought" about this? It's common medical practice to combine T4 and GH in growth retarted children, as well as patients with other problems. It's a very common practice, and has not only been well documented, it's been well researched.

For everyone here who has read the article I wrote (notably, I wrote it in co-operation with a Doctor, who is listed as an author of the piece along with me)- read it, and check all the references. You'll find P22's comments above to be absurdly and grossly misinformed.


Yes....to turn back time...LOL



in december 05 my father get a throat cancer. it was a really bad news.. i think you can understand. But my father was an heavy smocker and he say "well, i'm waiting for that.."

by now (for luck or god.. i dont bother) the cancer was defeated by the radio and chem cycle.

i dont smoke, i dont drink.However in the middle of may 03 i had a a big car "crash" (my friend, whom driving feel asleep..) i lose the use of one eye. the only one i have full working. I was completely blind for 2-3 months than slowly start to see a little better. In the middle i've lost my girl.. thinks that happens...

i have learn just 1 little stupid think: don't worry. Life is a river.. it flow on it's way.. you can choose how to travel the river. But the direction where you'll go is a choice of the river only...

i know, this my way of living... i dont suggest to other neither want that other understand.. but.. well i think that way is better than other for me.


i'm not immortal.. so why bother for the indevitable?