So I started a new iteration keeping my NDT at 0.75 grain, and Up the T4 to 75mcg, for a Total theoretical T4 impact of 123 mcg, and a T4/T3 ratio of 15:1. Biochemical abnormalities include low/low-normal T4 and high/high-normal T3 concentrations, a subnormal T4/T3 ratio, variably reduced reverse T3, raised muscle creatine kinase and mild anaemia. There is no correct or ideal ratio of FT4:FT3.If all doctors insisted on a simplistic 4:1 ratio of T4 to T3,  this would effectively force many thyroid patients to be in permanent ill-health!This argument is supported by a vast amount of patient experience.All you can do is to assess how the thyroid patient responds to the thyroid medication. But they actually are not. We already discussed the importance of T3 and how it does pretty much all of the heavy lifting when it comes to thyroid function in your body. Then, TSH will fall again if or when T4 rises too high. You can test for reverse T3 with a simple blood test. Kabadi, U. M., & Cech, R. (1997). His three books cover all of this.Is it Possible to Predict T3 Dosage When Changing Thyroid Medication to T3?Like this post? The peripheral conversion of thyroxine into triiodothyronine (T3) and reverse triiodothyronine (rT3) (PhD, University of Amsterdam). Go to page 5 in this thesis and you will see the diagram, which I also ethically reproduce on my blog within fair use copyright law for the purposes of critique and review.As far as I’m aware, nobody since 1979 has updated this information and compiled it in a single article that includes T4, T3, RT3 and gives “ranges” as numbers, so I’m giving you the latest research results!In Wiersinga’s diagram, he outlined that T3 secretion from a human thyroid gland ranges from 5.9 to 11.1 nmol/day, and T4 secretion approximately 116 nmol per day.Interestingly, he doesn’t give a range for T4 secretion, but he does for everything else.The T3 T4 ratio (expressed with T3 first) on his diagram ranges from 5.1 to 9.6% of total gland hormone production.If you invert the T3:T4 and express it as a T4:T3 ratio (not counting, for now, the smaller amounts of RT3 secreted by the thyroid), you get a range from “19.6 to 1” to “10.41 to 1.”Now let’s calculate his version of the 20% – 80% ratio.

Normal thyroxine and elevated thyrotropin concentrations: evolving hypothyroidism or persistent euthyroidism with reset thyrostat. Bypassing T4 to T3 Conversion with T3 Medication.

With the “free T3″/RT3 ratio, healthy ratios will be 20 or higher. Where the two tests disagree, it is desirable to calculate a Free T4 Index (FT4I) from the total T4 and Percent Uptake results, to determine how far alterations in circulating thyroid hormone carrier proteins.A high T4 level accompanied by a low Percent Uptake level suggests an increase in the concentration of thyroid hormone-binding proteins.

17. Have human bodies evolved a lot since then? If they need to switch, the T4 probably is not working well, which makes it harder to get an idea. This conversion process matters if you have a thyroid, if you don't have a thyroid, if you have Hashimoto's, if you have thyroid nodules, if you have thyroid cancer and so on. In part 1 of this series, “The foundations of synthetic T3-T4 therapy in the 1990s,” I examined Escobar-Morreale’s inaugural study of T4 monotherapy in the rat. I am struggling to lose weight and at a loss what to do next. You see this in the healthy control populations in studies of the HPT axis. Your two lab results can come in different units of measure, making it hard for the “math-challenged” to know how to convert the measurements into the same units in order to find the ratio. Laurberg, P. (1984).

Why? 5. Biochemical abnormalities include low/low-normal T4 and high/high-normal T3 concentrations, a subnormal T4/T3 ratio, variably reduced reverse T3, raised muscle creatine kinase and mild anaemia.