Research Studies: Use of Ranges is Flawed, rT3 is Active, TSH should NOT Guide Treatment

I have collected the references of various important research papers together into this blog post.

This is a fairly recent and terrific piece of research that clearly places FT3 centre place as the most useful lab test measure, as it correlates to symptoms more than the others. In addition to this, the research shows that in T4-monotherapy many patients did not find symptomatic relief until FT3 was elevated in the range and TSH suppressed

This is a quite a complex article but well worth the read as it talks about the need for a new diagnostic and treatment approach

Here is another relevant article on why the current paradigm of T4 monotherapy is flawed - this time by Dr Toft:

The way TSH is currently used is wrong, the way people are treated as if they are all the same is wrong, and simply being 'in range' on levothyroxine monotherapy is not going to guarantee a good outcome. Thyroid patients already know that we are all individuals, and many of us require either some T3 with T4, or all T3 in a few cases. We also know that we should not be managed by simplistic measures like TSH. The next piece of research is undoubtedly one of the most important studies done in the last ten years or so (perhaps 30 years). It finally begins to be more clear that TSH is one of the least useful tools in assessing thyroid hormone levels and whether someone is actually getting enough T3 in the cells. It states clearly that TSH should be downgraded to a merely supporting role, and that the role of free thyroid hormones are more important. It also states that other/new biological markers are actually required to assess if thyroid hormones are actually sufficient and working well for the individual. There is still huge work to be done, but this research is pointing the way and it says what we thyroid patients have known for a very long time:

This is an older research paper but showsn that reverse T3 (rT3) is a T3 blocker and not an inactive metabolite:

Here is a new piece of research that further supports our experience that T4 monotherapy using Levothyroxine is problematic and cannot re-create our previously healthy levels of FT4 and FT3. The study in rats at present actually found that T4 monotherapy resulted in lower than required FT3 levels. This was corrected with continuous release of both T4 and T3 medication in an appropriate ratio:

A new research paper has been published by Rudolf Hoermann, John E.M. Midgley and Johannes W. Dietrich. It is published in the Clinical Endocrinology Journal. Some of the take away conclusions are that "in some people no amount of T4 will regain normal FT3 levels" and that "...gurus now admit that some people cannot handle T4 and regain health". The links to the abstract and to download the full paper are: and

Here is a new 20 year observational piece of research. It dismisses the incorrect views that T3 has adverse effects on the bones and heart! It confirms that T3 has no adverse effects on heart and bones. This disproves some of the major reasons that doctors use to avoid prescribing T3 - risk to the heart and to bone loss are the two most common reasons used to avoid prescribing T3 to patients, although many of us suspect that cost is the unsaid reason behind non-prescribing of T3:

Another fantastic research article that is putting the knife into TSH as a truly unhelpful diagnostic test of whether thyroid patients are being properly treated. At last it appears that medical research is telling us what we have know for years:

Getting TSH into the reference range is no guarantee of good health. Here are some research papers that begin to show how simplistically and poorly TSH is being used today by most doctors. These medical research papers are complex but for those that want to read them they will show that the TSH is not something that should be relied upon in the way it is being done at the present time: and and and

Best wishes,


(Updated in February 2019)