Explain to me why T3 is absorbed orally, please!

**Atomini** · 12-24-2007, 11:32 AM

Triiodothyronine is a protein hormone. It can be absorbed orally.

HGH is a protein hormone. It must be injected, otherwise it is broken down into amino acids in the stomach if ingested.

Am I missing something here? Why can T3, even though it is a protein hormone, be absorbed through the digestive tract? Because it's a protein hormone, shouldn't it NOT be able to be absorbed orally due to the fact the body would treat it just as if it was chicken?

Can someone answer this please?

**pr0digy9daniel** · 12-24-2007, 12:55 PM

I beleive T3 is only one or two amino acids joined together, with some Iodide atoms in the molecuee. I am not sure on the exact specifics, although I dont think its a large macromolecule like insulin or HGH... Someone correct me though...

**magic32** · 12-28-2007, 11:08 AM

Originally Posted by Atomini

Triiodothyronine is a protein hormone. It can be absorbed orally.
HGH is a protein hormone. It must be injected, otherwise it is broken down into amino acids in the stomach if ingested.

Am I missing something here? Why can T3, even though it is a protein hormone, be absorbed through the digestive tract? Because it's a protein hormone, shouldn't it NOT be able to be absorbed orally due to the fact the body would treat it just as if it was chicken?

Can someone answer this please?

I like your questions, their always poignant.

Firstly, though taken orally, neither T3 nor chicken are absorbed orally, but rather intestinally.

Secondly, this intestinal route only permits preliminary absorption, e.g. access to the bloodstream. The actual absorption occurs at the appropriate level, as dictated by the nature/composition of the absorbed element, i.e. the cell walls of various or specific tissues, or diverse receptors (adenosine, androgen, beta, dopamine, histamine, etc.)

The function of the thyroid gland is to take iodine, found in many foods, and convert it into thyroid hormones: thyroxine (T4) and triiodothyronine (T3). Thyroid cells are the only cells in the body that can absorb iodine, thus ensuring constant production w/o competition. It then combines iodine w/L-tyrosine to make T3 and T4. Both hormones are then released into the blood stream and transported throughout the body where they control metabolism, e.g. the conversion of oxygen and calories into energy. Every cell in the body depends upon thyroid hormones for regulation of their metabolism, with the normal thyroid gland producing about an 80:20 ratio of T4 to T3 respectively. However, T3 possesses about four times the hormone "strength" of T4. Our synthetic addition of Cytomel , and other variants, serves to increase the aforementioned percentages to better achieve the natural end result.

Pharmacokinetically speaking, since Cytomel is not firmly bound to serum protein it is readily available to bodily tissues and is almost totally absorbed (95%) within four hours.

CYTOMEL INFO: http://www.kingpharm.com/kingpharm/u...mel_Web_PI.pdf

**Indymuscleguy** · 12-28-2007, 12:05 PM

Great info here! Now, if one doesn't have a functioning thyroid and is on 175mcg of T-4 and 10mcg of T-3, then how does one convert or better yet, increase T-3 to increase metabolism? I see guys on here using 30-50mcg per day, with a functioning thyroid. Mine is gone to to an overactive thyroid disease called 'Graves Disease'. My TSH was 0 or zero and once the thyroid was treated, my TSH went as high as 95. Ninety-Five...yes! Now my TSH is 0.48.

**edit: I realize that the doseage of T-3 is somewhat dependent on BMI and/or body weight. As a reference I'm 5'11" and 180lbs.

I am looking into an appropriate and safe doseage when I do my next cycle. I have lost muscle size as expected. I have not been cleared to workout since I developed not only Graves diseas of the thyroid, but also Graves Opthamia and Increased intra occular pressure. I had a bi-lateral orbital decompression surgery to save my sight. I am much better but still not cleard to workout!!!

Any ideas>

Thoughts, suggestions?

**pr0digy9daniel** · 12-28-2007, 01:05 PM

I take 125mcg of cytomel and my thyroid is perfectly functioning. Magic explained things well. However, I think the actual reason T3 is absorbed is because its a relatively small molecule which binds with receptors easily, as opposed to a really large protein which is broken down by protease enzymes.

**Indymuscleguy** · 12-28-2007, 01:29 PM

That seems aggressive, however this is all new to me. What's your weight? How long do you run then rest?

**Atomini** · 12-28-2007, 02:54 PM

You know what, I spoke to my uncle who is a bio-chemist and he explained it perfectly to me.

T3 is actually NOT a protein hormone. It's actually classified as an Iodiniated Amino Acid. Meaning, it's chemical structure is composed of 3 Iodines attached to ONE amino acid. Therefore, as some of you have already said, it's structure is simple enough and small enough that the body's digestive enzymes won't rip it apart. It'll just pass through into the bloodstream and off it goes to do it's job.

**Jay-Ace** · 12-28-2007, 04:25 PM

Originally Posted by Atomini

You know what, I spoke to my uncle who is a bio-chemist and he explained it perfectly to me.

T3 is actually NOT a protein hormone. It's actually classified as an Iodiniated Amino Acid. Meaning, it's chemical structure is composed of 3 Iodines attached to ONE amino acid. Therefore, as some of you have already said, it's structure is simple enough and small enough that the body's digestive enzymes won't rip it apart. It'll just pass through into the bloodstream and off it goes to do it's job.

Yup you had mislead yourself a little with your thinking of it as a "protein" hormone... It is in fact a Peptide Hormone as you quite rightly said it is only formed of 1 amino acid.

As the various GI enzymes, classified as Protease, proteolyse the various proteins contained in your diet via hydrolysis the T3 is unaffected....

Wow that was fun!!

**Indymuscleguy** · 12-29-2007, 08:17 AM

Bump...Again, those who don't have a thyroid and taking 175mcg of T-4 (which ~1/3 is converted to T-3) and in additon is taking 20mcg of T-3, that equates to ~60mcg per day from the T-4 plus th 20mcg of T-3 is 80mcg of T-3 each day.

Does the above correct and should I suppliment with more T-3. I gained 20lbs when the Thyroid was obliterated by the Iodine treatment, but after ~5 months I am down to 175-180. My normal weight is ~160 off cycle and on-cycle is ~180-185.

My goal is to get down to the 165-170 mark on a clean/leaning cycle.

Thoughts/coments?