I have worked with thousands of thyroid patients over the past fifteen years. In my Recovering with T3 book back in 2011, when the first edition was released, I made it very clear that I believed that it took between 40 and 80 mcg of Liothyronine (T3) to correct hypothyroidism in most thyroid patients who were using T3-Only. A few patients may need a little less and some need more than this. This was based on endocrinology texts and also on a lot of my experience with working with thyroid patients who needed to use T3 in order to recover from hypothyroidism. I still stand by this view.
Here is an article by Dr Tania S Smith of Thyroid Patients Canada. The article refers to various studies that suggest a typical replacement dose of T3 that is very close to the 40 – 80 mcg range that I have mentioned. One study that Dr Smith cites concludes that a full replacement dose of T3 is 50 – 100 mcg, and another concludes that 50 – 120 is required to achieve a euthyroid state. These numbers are totally consistent with the information that I provide in my Recovering with T3 book.
The title of the article, and much of the content, is about the equivalency of T3 to T4 medication. It is clear from the research studies that there is not a fixed mathematical equivalence. We are not robots, and as human beings we vary considerably in our ability to convert from T4 to T3. However, the past studies referred to suggest that in many cases it requires 25 – 35 mcg of T3 to replace 100 mcg of T4 medication. There will of course be some people that might need more or less T3. In all cases, only the use of the patient’s clinical presentation (symptoms and signs) would actually reveal if the individual is on the correct dosage and is effectively euthyroid.
I thought the article was very well written and interesting. I think that you will too.
Here is the link:
https://thyroidpatients.ca/2019/09/19/no-25-mcg-of-t3-liothyronine-isnt-equivalent-to-100-mcg-t4/
In a recent blog post I have discussed why multi-dosing with T3 is the most effective and safest way to deliver the total daily dose of T3 medication. I include this link because it is so relevant to this post. The two articles form a useful pair of blog posts. Together, they cover:
1) How much T3 is usually required to provide a full replacement T3 dose (this blog post).
and
2) Why 3-4 multi-doses of T3 is often the best way for thyroid patients to take that full replacement dose of T3.
Here is the link to the blog post on multi-dosing of T3:
https://paulrobinsonthyroid.com/why-t3-or-liothyronine-is-usually-taken-in-multi-doses-per-day/
Best wishes,
Paul
Isn’t it difficult to take T3 in three doses and avoid food at the same time? How would you do this? I am currently doing twice daily doses, once in early morning and once around 3 pm. It seems to help, but I don’t know how I could do it three times per day and avoid food.
Hi Debbie,
T3 is not the same as T4 or NDT. T3 can even be taken with food – so easily does it absorb.
So, no, food is a non-issue with T3.
Best wishes, Paul
Hi Paul,
Do you think that bodyweight comes into account? I am 106kg at 6’2” and have been using 25mcg T3 only per day, split into 2 divided doses of 12.5mcg in the am and pm. Wondering if I should increase to 37.5mcg or 50mcg. I carry a lot of muscle mass and am single-digit bodyfat. Can’t use T4 as it raises my rT3 through the roof and worsens my symptoms.
Hi David,
Usually not. At least it isn’t obvious to me in all the people I have worked with.
Often the individual’s issues are just that – individual. They need a solution geared for them.
If you have read either Recovering with T3 (which you should) or The Thyroid Patient’s Manual then you’ll see that a typical full replacement dose of T3 is between 40 and 80 mcgs per day – usually split into 3 doses. That is for full replacement. If you thyroid gland is working or partly working and all you are trying to do is to increase FT3 a little then you may get away with less.
However, 25 mcg us far from a replacement doses of T3. I would be working towards 3 doses and using the Recovering with T3 book protocol to manage the change towards this.
Best wishes, Paul
Hi Paul,
Done as instructed. I am now taking 12.5mcg of T3, 4 x per day for a total of 50mcg. Taking it every 4 – 4.5 hours and I feel significantly better. Much more energy and focus, improved moved and my metabolism has ramped up. I also feel less hungry and my blood pressure has lowered. This hormone is an absolute miracle.
Thank you very much for all the work that you do. This has drastically improved my life.