# Cytomel~T3



## heavyiron (Dec 9, 2009)

*Cytomel*

*(liothyronine sodium)*

Cytomel is a synthetic T3 hormone. As you may already know, most natural T3 is not produced directly by your thyroid gland, but rather is converted from the T4 thyroid hormone. (8)

*Cytomel T3 Weight Loss*

Natural T3 is a regulator of the oxidative metabolism of energy producing substrates (food or stored substrates like fat, muscle, and glycogen) by the mitochondria. The mitochondria, as you will recall from your high school biology class, are usually referred to as the "cell´s powerhouses" because they produce ATP. Taking Cytomel (supplemental T3) greatly increases the uptake of nutrients into the mitochondria and also their oxidation rate (i.e. the rate at which they are burned for energy), by increasing the activities of the enzymes involved in the oxidative metabolic pathway. Everything is working harder, in other words, and more fuel is needed to supplement this increased work rate. Therefore, as you can guess, taking supplemental Cytomel will increase your body´s energy demands. And if you are in a hypocaloric state, you will begin burning even fatter primarily due to an increase in ATP. This increased ATP causes an increase in overall metabolic activity. (8)(9)This is exactly what we want, and is why we would be taking thyroid hormones like Cytomel in the first place. If you aren´t taking anabolic steroids with your Cytomel, however, your body may start to eat away muscle to provide energy for you to function. Remember mitochondria/ATP aren´t very picky, but they are very efficient. What I mean by this is that they will use whatever is on hand to generate energy for your body to continue functioning, fat, protein, glucose; it doesn´t matter to ATP, as long as there´s something to give them energy. Taking this drug will increase their need to find something to burn to create this energy. Ergo, if we aren´t taking anabolic steroids while taking our T3, we may lose too much muscle, especially while dieting. 

Thus we can see that there are many advantages to using Cytomel to optimize our metabolic rate. It will also increase your body´s ability to synthesize protein, but from what I´ve seen personally, it acts as a catabolic when it isn´t administered with anabolic steroids. It is often the last thing added into a precontest diet, as it has a reputation for getting rid of the last few percentages of bodyfat& the "sticky fat" as it´s called in bodybuilding, the fat that just doesn´t want to leave you in the last few weeks of dieting. I think this is a poor use for this drug, and that it should be the first thing added into a diet to lose fat, as it will optimize your metabolic rate, which should be done at the outset of a diet, not after the calorie restriction has diminished your thyroid output and you are adding it in simply to replace what was lost.

*Cytomel Side Effects*

Unfortunately, in all of the studies I´ve seen, T3 also increased growth hormone production. (5)(6) As we all know, GH is also a strongly lipolytic compound, and this is another mechanism by which T3 may exert its effects, although I suspect this would only be a small percentage of its overall effects. This being the case, it has always been somewhat problematic to me to note that when GH and T3 are used together, the increased nitrogen retention normally found with GH use is negated. (7). If you were only using T3 and GH this may be a problem, but as I´ve already stated, you are going to need some anabolic agents if you are using T3. And as you have read previously, I recommend the veritable anabolic/lipolytic orgy of Insulin, T3, Anabolic Steroids, GH, and insulin, for 100% maximum results in minimal time.

On the brighter side, and of special note to dieters, administration of T3 has been shown to upregulate the beta 2 receptors in fat tissue. As you know clenbuterol and similar compounds downregulate this receptor, so using T3 with your clen will help stave off or reverse this downregulation. (1)(2)(3)(4). I would still recommend taking your benadryl every third week, though.

*Going off cytomel*

Finally, I would like to address the issue of recovery of your natural thyroid function after you stop taking cytomel. The horror stories of people on permanent thyroid replacement just aren´t true. I remember a few years ago, the rumor was circulating that the current Ms.Fitness had permanently shut off her thyroid gland, and was now fat and on thyroid hormone permanently. This is just another horror story based in nothing but conjecture and rumor, the studies I´ve looked at have shown people recovering their thyroid hormone relatively quickly (within months, at most) after going off of several YEARS (!) of thyroid replacement therapy (10)(11). I speculate that you can optimize your metabolic rate with Cytomel for 9-10 months a year, and just normalize yourself for 2-3 months (perhaps the winter, when you are mostly covered up), and then go right back on. Some people in the studies I read were on T3 for 30 years and recovered their natural thyroid function within short order. I think we can safely spend an athletic career using Cytomel 9-10 months out of the year, and just taking those few months off to normalize ourselves. Is this aggressive? Yes. Is this unsafe? NO.

*References:* 

1. Catecholamines inhibit Ca(2+)-dependent proteolysis in rat skeletal muscle through beta(2)-adrenoceptors and cAMP. Navegantes LC, Resano NM, Migliorini RH, Kettelhut IC Am J Physiol Endocrinol Metab 2001 Sep;281(3):E449-54 

2. Regulation of human adipocyte gene expression by thyroid hormone J Clin Endocrinol Metab 2002 Feb;87(2):630-4 Viguerie N, Millet L, Avizou S, Vidal H, Larrouy D, Langin D. 

3. Alpha 2- and beta-adrenergic receptor binding and action in gluteal adipocytes from patients with hypothyroidism and hyperthyroidism Metabolism 1987 Nov;36(11):1031-9 Richelsen B, Sorensen NS 

4. Regulation of beta 1- and beta 3-adrenergic agonist-stimulated lipolytic response in hyperthyroid and hypothyroid rat white adipocytes Br J Pharmacol 2000 Feb;129(3):448-56. Germack R, Starzec A, Perret GY 

5. Role of thyroid hormone in the control of growth hormone gene expression Braz J Med Biol Res 1994 May;27(5):1269-72. Volpato CB, Nunes MT. 

6. Low-dose T(3) improves the bed rest model of simulated weightlessness in men and women. Am J Physiol 1999 Aug;277(2 Pt 1):E370-9 Lovejoy JC, Smith SR, Zachwieja JJ, Bray GA, Windhauser MM, Wickersham PJ, Veldhuis JD, Tulley R, de la Bretonne JA. 

7. Effects of long-term growth hormone (GH) and triiodothyronine (T3) administration on functional hepatic nitrogen clearance in normal man. Wolthers T, Grofte T, Moller N, Vilstrup H, Jorgensen. J Hepatol 1996 Mar;24(3):313-9 

8. Human Anatomy and Physiology, 6th Edition. John w. Hole jr. 

9. Physicians Desk Reference 

10. Recovery of pituitary thyrotropic function after withdrawal of prolonged thyroid-suppression therapy. N Engl J Med 1975 Oct 2;293(14):681-4 Vagenakis AG, Braverman LE, Azizi F, Portinay GI, Ingbar SH. 

11. Patterns off recovery of the hypothalamic-pituitary-thyroid axis in patients taken of chronic thyroid therapy. J Clin Endocrinol Metab 1975 Jul;41(1):70-80 Krugman LG, Hershman JM, Chopra IJ, Levine GA, Pekary E, Geffner DL, Chua Teco GN


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## heavyiron (Dec 9, 2009)

What I found interesting about this profile of T3 was the fact that recovery after years of use happened within a few weeks of cessation of T3. On the net there are tons of people saying you may permanentaly shut down your thyroid with prolonged use of T3 but science says the opposite.



*Recovery of pituitary thyrotropic function after withdrawal of prolonged thyroid-suppression therapy. *

Vagenakis AG, Braverman LE, Azizi F, Portinay GI, Ingbar SH.

The pattern of thyrotropin secretion was analyzed in seven euthyroid women, before and after withdrawal of long-term thyroid hormone, by serial measurements of thyroid 131l uptake, serum thyroxine, tri-iodothyronine, and thyrotropin concentrations, and the response to thyrotropin-releasing hormone. During exogenous hormone administration, 131l uptake was suppressed, and serum thyrotropin concentrations before and after administration of thyrotropin-releasing hormone were undetectable. After withdrawal of exogenous hormone, thyrotropin secretory function was transiently impaired, as indicated by undetectable basal thyrotropin concentrations together with absence of response to thyrotropin-releasing hormone, and subsequently by normal values of basal thyrotropin concentration and normal responses to releasing hormone while serum thyroxine and tri-iodothyronine concentrations were subnormal. Decreased thyrotropin reserve persisted for two to five weeks. Detectable values of serum thyrotropin (less than 1.2 muU per milliliter) and a normal 131l uptake usually occurred concurrently in two to three weeks. Serum thyroxine concentration returned to normal at least four weeks after hormone withdrawal.

PMID: 808728 [PubMed - indexed for MEDLINE]


*Patterns off recovery of the hypothalamic-pituitary-thyroid axis in patients taken of chronic thyroid therapy. *

Krugman LG, Hershman JM, Chopra IJ, Levine GA, Pekary E, Geffner DL, Chua Teco GN.

To determine the patterns of recovery of the hypothalamic-pituitary-thyroid axis following long-term thyroid hormone therapy, TRH tests were performed on 8 euthyroid nongoitrous patients, 5 euthyroid goitrous patients, and 5 hypothyroid patients while they were taking full doses of thyroid hormone and 3, 7, 10, 14, 17, 21, 28, 35, 42, 49, and 56 days after stopping it. Serum TSH, T3, and T4 were measured before and at multiple intervals over a 4-h period after giving 500 mug TRH iv. In euthyroid non-goitrous patients, the mean duration of suppressed TSH response to TRH (maximum deltaTSH less than 8 muU/ml) was 12 +/- 4 (SE) days after stopping thyroid hormone and the mean time to recovery of normal TSH response to TRH (maximum deltaTSH greater than 8 muU/ml) was 16 +/- 5 days. None of the euthyroid nongoitrous patients ever hyperresponded to TRH; their average maximal deltaTSH was 24.5 +/- 2.2 muU/ml. Serum T4 fell below normal in 4 euthyroid non-goitrous patients, reaching lowest values at 4 to 28 days. While serum T4 was low, deltaTSH was subnormal. Normal increments of T4 and T3 after TRH occurred at 19 +/- 5 and 22 +/- 6 days, respectively. In the 5 goitrous patients, patterns of recovery of pituitary and thyroid function assessed by the same parameters were much less consistent. In the 5 hypothyroid patients, the mean duration of suppressed basal TSH and suppressed deltaTSH was 13 +/- 3 days; mean time to attain a supranormal basal TSH (greater than 8 muU/ml) was 16 +/- 4 days and to reach a supranormal deltaTSH (greater than 38 muU/ml) after TRH was 29 +/- 8 days. Following prolonged thyroid therapy in euthyroid patients, recovery of normal TSH responsiveness to TRH preceded recovery of the normal T3 and T4 response to TRH by 3 to 6 days. Basal serum TSH may be used to differentiate euthyroid from hypothyroid patients 35 days after withdrawal of thyroid therapy; the response to TRH does not improve this differentiation.

PMID: 807596 [PubMed - indexed for MEDLINE]


Related articles
[The hypothalamic-Pituitary thyroid axis: studies on the regulatory role of thyrotropin releasing hormone (TRH) (author's transl)] Nippon Naibunpi Gakkai Zasshi. 1976 Sep 20; 52(9):908-25. 
[Nippon Naibunpi Gakkai Zasshi. 1976]
The TSH response to thyrotropin-releasing hormone (TRH) in young adult men: intra-individual variation and relation to basal serum TSH and thyroid hormones. J Clin Endocrinol Metab. 1976 May; 42(5):809-16. 
[J Clin Endocrinol Metab. 1976]
Effect of prolonged oral administration of TRH on plasma levels of thyrotrophin and prolactin in normal individuals and in patients with primary hypothyroidism. Acta Endocrinol (Copenh). 1977 Aug; 85(4):744-52. 
[Acta Endocrinol (Copenh). 1977]
ReviewThyrotrophin releasing hormone--TSH. Clin Endocrinol Metab. 1977 Mar; 6(1):83-100. 
[Clin Endocrinol Metab. 1977]
Review[Lithium and thyroid function. Significance of the TRH test in the diagnosis of lithium-induced thyroid dysfunction] Encephale. 1979; 5(2):171-88. 
[Encephale. 1979]


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## VictorZ06 (Dec 10, 2009)

heavyiron. said:


> What I found interesting about this profile of T3 was the fact that recovery after years of use happened within a few weeks of cessation of T3. On the net there are tons of people saying you may permanentaly shut down your thyroid with prolonged use of T3 but science says the opposite.



Yeah, lots of new research has shed a different light on how to use this stuff.  

For a while now, most people who used it, would use it for short periods of time tapering up and down with doses (pyramid).  I've read new and more recent studies that claim that you won't "shock" your thyroid if you cut it cold turkey, thus no need to run short cycles or taper the doses up/down.

/V


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## WFC2010 (Dec 10, 2009)

i always use maxx 40mcg t3 a day


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## b1ggjoe (Dec 12, 2009)

Guys,

Do you think that HGH & T3 should not be used together...or do you think that together they can be synergistic?


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## VictorZ06 (Dec 12, 2009)

b1ggjoe said:


> Guys,
> 
> Do you think that HGH & T3 should not be used together...or do you think that together they can be synergistic?



Like I said in the other thread, HGH and T3 make for a great combo depending on what your goals are.  I like to run T3/Clen/HGH post cycle because T3 not only chews up fat, it eats muscle mass as well.

/V


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## b1ggjoe (Dec 13, 2009)

This post by 'Heavy Iron' is a great post!!


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## b1ggjoe (Dec 13, 2009)

Thanks Victor!!


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## heavyiron (Dec 15, 2009)

VictorZ06 said:


> Yeah, lots of new research has shed a different light on how to use this stuff.
> 
> For a while now, most people who used it, would use it for short periods of time tapering up and down with doses (pyramid). I've read new and more recent studies that claim that you won't "shock" your thyroid if you cut it cold turkey, thus no need to run short cycles or taper the doses up/down.
> 
> /V


Yup, I can jump on 50mcg's daily and jump off with zero problems.


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