More on Circadian Dose Size and Timing Adjustments

I have been having lots of discussions recently with people who wanted to know how much to increase the circadian dose when taken at one and a half hours before getting up before moving the circadian dose earlier in time. I hope this blog post helps to clarify this.

In the Circadian T3 Method (CT3M) the adjustment of circadian dose timing and dose size are both necessary.

A change to the time the circadian dose is taken provides a gentle change of FT3 level to the pituitary, in order to help it to provide the adrenal glands with the right level of ACTH. A later T3 dose ensures slightly less FT3 arrives inside the pituitary cells and usually produces a lower response from the adrenal glands. An earlier T3 dose allows slightly more FT3 may produce a larger response.

A change to the size of the circadian dose can produce very large effects as even small increases of 2.5 micrograms of T3 containing medication can increase FT3 levels in the cells.

Ideally, only enough T3 containing medication will be used but it will be taken early enough in the cycle of adrenal hormone production that it will fully support the pituitary and the adrenal glands.

The CT3M process begins by finding the smallest circadian dose size that has some positive effect on symptoms or signs taken at one and a half hours before getting up.

This initial circadian dose does not have to fully resolve symptoms – it only needs to have some detectable benefit.

Once the initial circadian dose is large enough to produce some effect then timing changes to the dose provide a smoother change in adrenal function. Adjusting the time of the circadian dose is the fine-tuning dial on cortisol in the CT3M.

Hence it is better to find the smallest circadian dose that appears to have some positive effect at one and a half hours before getting up, and then adjust the time of the dose to find the optimal time to take it. Only once the optimal time is found should the circadian dose be increased to discover the best dose size.

If the circadian dose is increased too much when taken at one and a half hours before getting up then when the circadian dose is taken earlier it can be far too potent.

Consequently, thyroid patients have found that using a circadian dose of 10, 12.5 or 15 micrograms at one and half hours before getting up is often a good starting point before adjusting the circadian dose in time. If this initial circadian dose size is slightly effective, titrating it back in time is an ideal way to proceed.

The initial circadian dose size does not need to resolve all symptoms it only needs to be seen to have some positive effects. Hence only a small increase in this starting circadian may be necessary from a starting dose of 10 micrograms of T3 containing medication. Some sensitive thyroid patients may need to begin with an even lower dose of T3 medication than 10 micrograms.

As already stated, increasing the circadian dose by even 2.5 micrograms can produce a very strong result. Consequently, adjusting the size of the circadian dose may be viewed as the rough-tuning dial on our cortisol level in the CT3M.

The optimal time to take the circadian dose is frequently somewhere between two and a half and four hours before the individual gets up in the morning, although there are exceptions to this with some people doing well at only one and a half hours before rising. Once the ideal time has been found to take the circadian dose then the circadian dose size may be increased further. After this further fine-tuning of both time and size of the circadian dose may be performed if needed based on symptoms and signs.

Therefore within the CT3M both time and dose size adjustments are required to tailor the necessary T3 support for good cortisol production.

Best wishes,


(Updated in January 2019)

Paul Robinson

Paul Robinson is a British author and thyroid patient advocate. The focus of his books and work is on helping patients recover from hypothyroidism. Paul has accumulated a wealth of knowledge on thyroid and adrenal dysfunction and their treatment. His three books cover all of this.

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