Reverse T3 Medication Question

[HypoCrazy]

hi there

Does anyone have any advice as to how many hours beforehand we should take T4 and T3 medication before a Reverse T3 test? Anything else to avoid beforehand or if I need to fast? Many thanks in advance 😃

[tattybogle]

i'm not aware of any research showing affect on ReverseT3 of time of last dose levo or T3 . so it's anyone's guess what/ if any , difference it may make to the result.

[HypoCrazy in reply to tattybogle]

thank you xx

[SlowDragon Administrator]

we don’t generally recommend Reverse T3 test

It’s extremely expensive (has to be sent to USA to process) and doesn’t tell you much

More important to test TSH, Ft4 and Ft3 together plus vitamin D, folate, ferritin and B12

What were most recent results

How much levothyroxine are you taking

Do you always get same brand at each prescription

What vitamin supplements are you taking

As you have Hashimoto’s are you on gluten free and/or dairy free diet

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

[HypoCrazy in reply to SlowDragon]

thank you Slow. I’ve already bought the test so do you think I’d be ok taking my last doses at any time the day before? I’m assuming I won’t need to fast x

[SlowDragon Administrator in reply to HypoCrazy]

What else is being tested?

[HypoCrazy in reply to SlowDragon]

It's just rt3, a Blue Horizon test 👍

[helvella Administrator]

If you have bought an rT3 test from a reputable source, they should back up their offering by telling you what might affect the results - such as taking thyroid hormones. Contact them. And let us know what they say, please!

It would appear illogical to stop taking T4, whatever else, as it is the T4 that gets converted into rT3. From simple thoughts, without scientific backup, I'd have thought that stopping T4 would tend to produce a lower rT3 result.

tattybogle

[HypoCrazy in reply to helvella]

It's a Blue Horizon test and comes with no advice sadly, but thank you for yours it makes a lot of sense! 😀