Dosing T3 and Checking in with Blood Tests

[Clara4741]

I have noticed on the forum that people have mentioned above taking T3 8-12 hours prior to doing a Blood Test to check in on the TSH, FT4, FT3 whilst find optimal dose. Please can someone explain the significance of this? I usually do a Fasting Blood Test around 9:15am (have been on Metavive to date) but have just added T3 so want to be clear how I prepare for my Blood Tests going forwards. Currently I taking the T3 with the Metavive on an empty stomach on waking - so am way off the timeframe of 8-12 hours before as I have seen people post.

I would also be grateful if people doing the combo and adding T3 could indicate how long they wait before increasing the T3. Obviously you know pretty soon if you are having any hyper symptoms but I am thinking about other symptoms like hair loss and weight which I am waiting to see progress with.

Many thanks in advance.

[SeasideSusie Remembering]

Clara4741

General advice about timing of thyroid meds prior to blood tests:

* Book the first appointment of the morning, or with private tests at home no later than 9am. This is because TSH is highest early morning and lowers throughout the day. If we are looking for a diagnosis of hypothyroidism, or looking for an increase in dose or to avoid a reduction then we need TSH to be as high as possible.

* Fast overnight - have your evening meal/supper as normal the night before but delay breakfast on the day of the test and drink water only until after the blood draw. Eating may lower TSH, caffeine containing drinks affect TSH.

* If taking thyroid hormone replacement, last dose of Levo should be 24 hours before blood draw, if taking NDT or T3 then last dose should be 8-12 hours before blood draw. Adjust timing the day before if necessary. Take your thyroid meds after the blood draw. Taking your dose too close to the blood draw will give false high results, leaving any longer gap will give false low results.

* If you take Biotin or a B Complex containing Biotin (B7), leave this off for 7 days before any blood test. This is because if Biotin is used in the testing procedure it will give false results (Medichecks definitely use Biotin, they have confirmed this and the amount of time to leave the supplement off).

These are patient to patient tips which we don't discuss with doctors or phlebotomists.

T3 has a short half life and it starts to become undetectable in the blood after 12 hours. So testing after that time gives a false low.

I would also be grateful if people doing the combo and adding T3 could indicate how long they wait before increasing the T3.

As you have been taking Metavive, what were your test results for TSH, FT4 and FT3 before you added T3? You need to know if you just need a little extra T3 or if you are very low in your FT3 level.

Have you started with just 1/4 of a T3 tablet added to your Metavive?

Depending on what your FT3 level was before you added T3, if it wasn't very low then I'd wait 6 weeks from adding the T3 then retest your levels. That will tell you if you have room to add a second 1/4 of a tablet.

Hair loss can be due to certain vitamin deficiencies:

hubpages.com/health/16-Vita...

[Clara4741 in reply to SeasideSusie]

Hi SeasideSusie,

Thanks for the info recap. I was on Metavive 60mg when my Medichecks Blood Test was done on the 18th June 2019. My results were: TSH 1.06, FT4 11.800, FT3 3.04. Over the years prior to taking any Metavive my FT3 was always around 3.0 then when I started experimenting with Metavive it never got much above 3 either until I let the dosing go right up (which suppressed my TSH a lot, not what I wanted to do ideally) but even then I only achieved a FT3 of 4.25. Then shortly after I went Thyrotoxic. I know I have poor conversion and am working on many different aspects of my health to sort this out. Some of these also add to the issue of the hair loss. I should add that all the usual Vitamins & Minerals your recommend on your forum are now optimised. I have also recently had a Full Thyroid Panel done with RT3. This was done when I had to come off the Metavive altogether for a couple of weeks but my FT3 went to 2.61 then and the Reverse T3 was 14 and the FT3:rT3 Ration was 12.14. I am using Functional Medicine Optimal Ranges for my reference points and Free T4 is 15-23 (never got near 15), Free T3 is 5-7 (never reached 5), Reverse T3 is 11-18 and FT3:rT3 Ratio 20 ideally or above. So after a long period of trialling Metavive and never being able to optimise my dose without going hyper, even with decent Iron Levels, I concluded I needed to add some T3.

I started on a quarter of a tablet (25mg per tablet) so 6.25mg. Then after about one week of feeling sleep quality was much better and energy better as a result of waking more refreshed I upped it to 12.5mg per day. After 9 days of feeling okay on that I upped it to 19.5mg and this is my second day of being on it. I am very familiar with dosing Metavive but less so with T3 hence my question, as all my reference points are for T3 only which is helpful but not quite the same. I was planning to retest my Bloods when in a few weeks time as I am going on my symptoms in conjunction with these obviously. I know everyone is different and there is no right answer for all but I am quite in tune with my body and so thought I would give it some time to see how I do. I am generally quite sensitive to dosing so figure with T3 I will know straight away if it is too much. I have been Hypothyroid for quite a while now and need to get out of this state but the Thyroid Hormone hasn't been getting into my cells despite going onto Metavive over nearly the last two years. I am hoping that the T3 will help.