I have changed from Levothyroxine only to Levothyroxine T4 50mcg daily. and Liothyonine. T3. 15mcg AM and 10mcg PM. I would normally take the AM dose of T3 at 7am with the T4 at 6am. I am due a thyroid blood test at 12.30pm.
Should I still take the T4 at 6am and T3 at 7am or adjust to take it after the blood test?
Advice please.
1839
We always advise the following time gaps:
Levo - last dose 24 hours before the blood draw
T3 - 8-12 hours before the blood draw, splitting dose and adjusting time the day before if necessary.
As your test is at 12.30pm then on the day before the test I would suggest the following:
* Delay your Levo and T3 until around noon - 1pm (one hour before food or two hours after), you can take both at the same time.
* Take your second dose of T3 no earlier than midnight, that will just scrape close to the 8-12 hour window.
Hi SeasideSuzie, Many thanks, a complication on your advice is that the blood draw is tomorrow at 12.30, so I am past the window for delaying it today. I should have asked advice before, sorry about that. what would you suggest in view of this please?
1839
Rearrange your blood draw?
If that's not practical then take your second dose of T3 no earlier than midnight tonight.
You will just get a false low FT4 result because of the time you took your Levo this morning but your FT3 result should be very near it's normal circulating amount.
Delay tomorrow's Levo and first dose of T3 until after the blood draw.
Hi, Many thanks, not practical to re arrange the blood draw so will do as you suggest
A bit off topic but one of your comments caught my attention and I'd appreciate your thoughts - is there such a thing as a "normal circulating amount" of T3 for someone on T3? My suspicion is that it must fluctuate significantly from one dose to the next because of the short half life and also the rate at which it's used up (which, in turn, is presumably governed by the activities undertaken by the individual at any particular time). For that reason, I would be surprised if the "normal" range used in blood tests is appropriate for someone taking T3. If you have any literature references that go into this, I'd be very interested.
Tcpace
The half life of T3 is 24 hours.
My response is based on the fact that T3 peaks in the blood 2-4 hours after ingestion so that's when you'd get the highest result recorded when tested, so by leaving 8-12 hours the peak will have passed and the level will be dropping to it's normal level.
My adjustment to T3 is fairly new, with the peak being 2-4 hours would there be an argument for splitting the daily dose to three times daily as opposed to twice like I am on? I have experienced a dip in energy after 5/6 hours. My Endo is working on my daily dose to get it right, but wondered if 3x dose should be considered.
1839
Everyone is individual in their needs. Some people are fine taking their T3 in one dose, others split it onto two doses, some taking three doses evenly spaced throughout the day. You have to experiment and find what's best for you.
Thankyou
I started the hypothyroid battle when I was told by an endo in hospital (after an accident), that I had a thyroid problem. At the time my TSH was over 5. I went to my doc and got a test but had in the afternoon - it showed 3.4 - No treatment needed. I persisted and got another test which I had done in the early morning. It showed TSH about 6, I eventually got Levo and my last test during another slight crisis was at midday. ( That was 1.45 after the meds) and that is OK with me at the moment. Moral of the tale. If possible get the tests done early morning - I have the luxury of living in France where I can go to the lab for the test from 7:30am. (The lab always asks if I have taken the levo) Best of luck.
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