Preventing TSH downregulation?

[TruffleGnocchi]

I've read a study that measured T3 and TSH contentrations. Subjects were given 50mcg. Peak was 2.5H, halflife around 6H. But TSH remained downregulated and only completely recovered after I think 70H.

T3 has to be one of the best molecules to have in stock. Are there ways to combat TSH downregulation when taking exogenous T3?

 

[mgrabs]

I've read a study that measured T3 and TSH contentrations. Subjects were given 50mcg. Peak was 2.5H, halflife around 6H. But TSH remained downregulated and only completely recovered after I think 70H.

T3 has to be one of the best molecules to have in stock. Are there ways to combat TSH downregulation when taking exogenous T3?

Are you saying t3 & tsh down regulates on t3 therapy?

 

[TruffleGnocchi]

Are you saying t3 & tsh down regulates on t3 therapy?

Single Dose T3 Administration: Kinetics and Effects on Biochemical and Physiologic Parameters

TABLE

I spoke too soon. It doesn't look that bad, only a small decrease in T3 compared to where it started, they stopped measuring after 96H unfortunately.

Looking at only this, TSH level continued to drop until 12-24H, but T3 continued to decline until 72-96H (towards what it was before and very slightly lower).
It took 48H after 50mcg T3 single dose for T3 level to decline back to what it was before the dose, but TSH at 24H was still only 1/3 and at 48H at 2/3 of what it was before, so 33% lower. Then TSH started to normalize or increase after that, but T3 kept falling a bit. At 96H TSH still around 15% down. That T3 continued fall could have been statistically insignificant, since it fluctuated like this also before T3 was given, but the levels of T3 and TSH seem more related on measurements before administration.

I wonder what happens with long-term T3 administration, and how long it takes for T3 production to get back to previous levels if stopping then, or if the body's ability to control its T3 is reduced. After 48H T3 was at 120, even though TSH was still 0.9, maybe could be a good thing, but I'm thinking about testicles shrinking when not stimulated enough because of exogenous androgen administration. Hope my thyroid doesnt athrophy from lack of need of endogenous production. It grows when not enough iodine to make T3. Maybe the lower TSH levels could sensitise the TSH receptors and actually help endogenous production eventually sometime after not taking T3 exogenously

Table 2​

Thyroid parameters prior to and after administration of 50 mcg T3

 

[sunny]

You would never want to take a bolus of 50 mcg of T3 in a single dose. If supplementing, it should be taken intermittently thru the day. Preferably in doses not more than 10 mcg at a time, probably 4-6 mcg would be best.

 

[mgrabs]

Single Dose T3 Administration: Kinetics and Effects on Biochemical and Physiologic Parameters

TABLE

I spoke too soon. It doesn't look that bad, only a small decrease in T3 compared to where it started, they stopped measuring after 96H unfortunately.

Looking at only this, TSH level continued to drop until 12-24H, but T3 continued to decline until 72-96H (towards what it was before and very slightly lower).
It took 48H after 50mcg T3 single dose for T3 level to decline back to what it was before the dose, but TSH at 24H was still only 1/3 and at 48H at 2/3 of what it was before, so 33% lower. Then TSH started to normalize or increase after that, but T3 kept falling a bit. At 96H TSH still around 15% down. That T3 continued fall could have been statistically insignificant, since it fluctuated like this also before T3 was given, but the levels of T3 and TSH seem more related on measurements before administration.

I wonder what happens with long-term T3 administration, and how long it takes for T3 production to get back to previous levels if stopping then, or if the body's ability to control its T3 is reduced. After 48H T3 was at 120, even though TSH was still 0.9, maybe could be a good thing, but I'm thinking about testicles shrinking when not stimulated enough because of exogenous androgen administration. Hope my thyroid doesnt athrophy from lack of need of endogenous production. It grows when not enough iodine to make T3. Maybe the lower TSH levels could sensitise the TSH receptors and actually help endogenous production eventually sometime after not taking T3 exogenously

Table 2​

Thyroid parameters prior to and after administration of 50 mcg T3

interesting. Nice find. Are you currently taking T4/T3?

 

[TruffleGnocchi]

I take around 3-12mg T3 or smaller doses multiple times, with around 20-30mg T4, as some mentioned it was good on this forum