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We often see a a lot of questions about thyroid hormones but I suspect there's not much understanding of exactly what these very powerful hormones can do other than greatly accelerate fat loss. So lets learn a bit more about this subject before we start searching the Internet for supplies for our next cutting cycle.
The thyroid is a little gland in the neck which creates the Adam's Apple bulge. It secrets hormones that manipulate the rate at which the body produces energy from nutrients. The thyroid makes several hormones, not just T3 which is the one we most frequently hear about.
The thyroid "cycle" starts with secretion of TSH (thyroid stimulating hormone) by the pituitary gland which tells the thyroid to release specific amounts of a hormone into the body.
The thyroid hormones include:
T4 (2 x diiodotyrosine)
T3 (triiodothyronine)
T2 (diiodothyronine)
T1
In response to the TSH mentioned above, the thyroid produces T4. Your thyroid converts T4 into T3 for release into the body. Of all the thyroid hormones, T3 is the most powerful for fat loss purposes, which is why it's the one we more often hear about. T3 metabolizes the beejezus out of stored body fat, but is also pretty damn hard on skeletal muscle too, meaning it is quite catabolic. You could lose as many as 3 pounds of muscle for every 5 pounds of fat that T3 mobilizes. This is one of the many reasons you want to take as little as possible of T3 in order to achieve your fat loss goals. More is worse, not better
Your thyroid can also use T3 to make T2. T2 is less powerful at eating up stored bodyfat, but it's also substantially less catabolic, which probably makes it a better choice for someone who wants to ensure they don't lose any hard earned muscle while trying to cut. Lastly, the thyroid can make T1 from T2, but it is substantially less powerful at mobilizing fat, so you probably won't ever see anyone selling it.
Now just like when you take steroids and suppress your own natural production of LH and Test, running T3 or T2 will suppress your body's production of TSH. T4 will suppress it the most, T3 less so, and T2 the least. (another reason I'd say T2 is a better choice) This means that when you cycle off you will have a pathologically low amount of thyroid hormone in your body for some period of time. How long? Not sure anyone could answer that given the number of unknowable variables, but certainly the pre-existing health of your thyroid, the specific drug you took, and the length of your cycle are huge factors. So the possibility of a fat gain rebound effect after cycle certainly exists.
These hormones have other profound effects on the body too, of which you definitely should be aware.
* Increased oxygen consumption (metabolic rate)
* Increased thermogenesis (heat production)
* Increased number of red blood cells
* Increased lypolysis (fat burning)
* Increased liver glycogen breakdown
* Increased liver glucose production
* Increased intestinal glucose absorption
* Increased protein turnover
* Decreased cholesterol levels
And some potentially harmful stuff you need to monitor which may completely preclude use of any of these hormones if you have pre-existing health problems.
* Increased heart rate and heart contractility
* Increased free radical production
* Increased potential for bone loss
* Increased cortisol levels
* Increased sex hormone binding globulin
The thyroid is a little gland in the neck which creates the Adam's Apple bulge. It secrets hormones that manipulate the rate at which the body produces energy from nutrients. The thyroid makes several hormones, not just T3 which is the one we most frequently hear about.
The thyroid "cycle" starts with secretion of TSH (thyroid stimulating hormone) by the pituitary gland which tells the thyroid to release specific amounts of a hormone into the body.
The thyroid hormones include:
T4 (2 x diiodotyrosine)
T3 (triiodothyronine)
T2 (diiodothyronine)
T1
In response to the TSH mentioned above, the thyroid produces T4. Your thyroid converts T4 into T3 for release into the body. Of all the thyroid hormones, T3 is the most powerful for fat loss purposes, which is why it's the one we more often hear about. T3 metabolizes the beejezus out of stored body fat, but is also pretty damn hard on skeletal muscle too, meaning it is quite catabolic. You could lose as many as 3 pounds of muscle for every 5 pounds of fat that T3 mobilizes. This is one of the many reasons you want to take as little as possible of T3 in order to achieve your fat loss goals. More is worse, not better
Your thyroid can also use T3 to make T2. T2 is less powerful at eating up stored bodyfat, but it's also substantially less catabolic, which probably makes it a better choice for someone who wants to ensure they don't lose any hard earned muscle while trying to cut. Lastly, the thyroid can make T1 from T2, but it is substantially less powerful at mobilizing fat, so you probably won't ever see anyone selling it.
Now just like when you take steroids and suppress your own natural production of LH and Test, running T3 or T2 will suppress your body's production of TSH. T4 will suppress it the most, T3 less so, and T2 the least. (another reason I'd say T2 is a better choice) This means that when you cycle off you will have a pathologically low amount of thyroid hormone in your body for some period of time. How long? Not sure anyone could answer that given the number of unknowable variables, but certainly the pre-existing health of your thyroid, the specific drug you took, and the length of your cycle are huge factors. So the possibility of a fat gain rebound effect after cycle certainly exists.
These hormones have other profound effects on the body too, of which you definitely should be aware.
* Increased oxygen consumption (metabolic rate)
* Increased thermogenesis (heat production)
* Increased number of red blood cells
* Increased lypolysis (fat burning)
* Increased liver glycogen breakdown
* Increased liver glucose production
* Increased intestinal glucose absorption
* Increased protein turnover
* Decreased cholesterol levels
And some potentially harmful stuff you need to monitor which may completely preclude use of any of these hormones if you have pre-existing health problems.
* Increased heart rate and heart contractility
* Increased free radical production
* Increased potential for bone loss
* Increased cortisol levels
* Increased sex hormone binding globulin
