Thyroid UK
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hormone levels on Thyroid-S compared to other brands of NDT

I was wondering if anyone here has tried both Thyroid-S and some other brand(s) of NDT, and noticed a difference in FT levels...?

I am asking because on Thyroid-S, my FTs tend to be rather low...or rather, my FT4 levels are really low (just above the normal lower limit), while my FT3 levels are midrange, 24 hours after latest dose. I recently read an article where it was stated that Thyroid-S (this article compared it to the two other Thai brands of NDT, Thiroyd and TR TMan) contains a substance causing it to release hormones more slowly into the bloodstream, and this in turn would result in a more stable delivery of thyroid hormones over several hours. I guess this could be interpreted to mean that FT3 levels won't peak and then fall just as rapidly.

It is possibly a good thing that FT3 levels are not out of range when you go to the lab, as that tends to cause most doctors to freak out. However, like any other drug containing T3 (and I have tried both synthetic combo drug Novothyral as well as Armour and Erfa), Thyroid-S suppresses my TSH completely (<0.01). That must mean that it is working on some level (at least that is my understanding...).

I am curious if anyone else has experienced this and, if so, how do you feel on Thyroid-S compared to other brands?

4 Replies

Thyroid S and Erfa are boTh manufactured to have a longer shelf life and need more breaking down than other ndt's. Will add a link in a moment.....

I cannot break down the thyroid S and it makes me feel hypothyroid. I do fine with Thyroid, or naturethroid....


Here is the link.

Here is the relevant paragraph

“Here is your data…

Since the data for Thyroid-S was not encouraging last time I did a little extra work to sort this out. There are 2 sets of data.

The first, Digestion Only, is what I did last time. Digestion, dilute and analyze. It worked fine for Thiroyd, but did not work as well for Thyroid-S. Just like last time.The second, is a methanol extraction of the digest. Digest, extraction, dilute and analyze. This worked great for Thiroyd and ThyroidS. There must be something in the Thyroid-S tablet that is holding onto the T3/T4. The methanol was needed to set it free.The reported concentrations are in relation to a single pill of Cynoplus, so the data must be taken in context.Overall I think you can be happy with both of your products.”


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I have actually been wondering if whatever substance in Thyroid-S makes it less absorbable actually prevents my FT3 levels from peaking, something that always happens on brands of NDT without cellulose. Personally, I feel better when that does not happen, but I guess it's highly individual. For some strange reason, I feel good on Thyroid-S, although my FTs are not nearly as high as on other NDT drugs such as Erfa or even Thiroyd. Has anyone else experienced the same thing?


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