When to take second dose T3 prior to blood test?

[Piglet1956]

I have a blood test to check levels next week. I take Levo in the morning around 6am along with 5 mcg Lio and then another 5mcg Lio around 6pm in the evening. Would some kind person please remind me when I should take my evening dose of Lio the night before a 8:40am blood test. Thank you.

[SlowDragon Administrator]

ideally you would take levothyroxine 8-9am morning before test

9pm would be about perfect for last T3 dose

[Piglet1956 in reply to SlowDragon]

Thank you SlowDragon. I couldn’t remember if it was 8 or 12 hours prior to blood draw.

[SeasideSusie Remembering in reply to Piglet1956]

Piglet1956

8-12 hours is what we advise, whatever in that window is most convenient for you. For example, if your test is at 9am then you could take your last dose between 9pm the night before and 1am, your bedtime could be the deciding factor. I tend to go straight down the middle and leave 10 hours.

[Piglet1956 in reply to SeasideSusie]

Thanks for your reply. What you say makes sense and probably explains why I had 8 or 12 hours in my head

[Joyya in reply to SlowDragon]

Rather than start a new post, I am going to ask my question here. I am having TSH, fT4 and fT3 tested next Monday morning at 7 AM. I am currently taking Synthroid 75 mcg along with a Cytomel 5mcg at 4:30 AM and a second Cytomel 5 mcg at noon. Do I understand correctly that I *do* take my Synthroid the morning of the test, but not the Cytomel? Last time I had the test (also at 7 AM) I didn't take any meds until after. If we are comparing results, would it make the most sense to also not take meds until afterwards this time, too?

Thanks!

[SlowDragon Administrator in reply to Joyya]

last dose levothyroxine 24 hours before test ….so 7am day before test

Last dose T3 approx 8-12 hours before test…..you might split noon 5mcg dose ….taking 2.5mcg at noon and 2.5mcg at 7pm day before test

[Joyya in reply to SlowDragon]

thanks! What would be the benefit of splitting the noon dose and taking the other half at 7 PM? How would it affect test results?

[SlowDragon Administrator in reply to Joyya]

Many members split T3 as 3 doses every day

Rather than moving whole 5mcg dose from noon to 7pm (if you have 5mcg pill ) cut in half and take half at noon and half at 7pm

[McPammy]

I continue to take my lio at my normal times the day prior to my blood draw which is 7.30am then 3pm. I spilt my levothyroxine also 12.30 then 5pm. I don’t take any medication on the blood draw day prior to the appointment time. I normally make my blood draw appointment for 9am and take my lio directly afterwards. I like to see how low my T3 level is on a morning day to day basis before ingestion. I recently had a face to face consultation with my NHS endocrinologist. He was very pleased indeed that my levels are in range and importantly to him that my TSH is in range. He said he has no issues with prolonged prescription for liothyronine, mainly to do with my TSH being in range. Importantly though to me that I do feel very well and energised.

[Piglet1956 in reply to McPammy]

Thanks McPammy. That’s very helpful. I’m glad you’re feeling well and you’re endo is supportive.