Advice needed

[Kittymeowmeow42]

Hey! I’ve just had my bloods done recently and my GP has noted both my TSH and T4 were both low. He’s suggested increasing my Levo dose to 75mg. I take this alongside 50mg of T3. What does it mean when both are low?

[Hennerton]

Nobody can tell you unless you post the actual figures with the reference ranges. Doctors say all kinds of odd things, as mostly they do not understand the blood tests themselves. For both to be low is odd. Ask for free T4, free T3 and TSH. I doubt if the lab did T3 so he cannot really say what is necessary but whatever he did is a better start than nothing...

[Jazzw]

Honestly? Not a lot when you take T3. FT4 and TSH are often very low when you take T3 and the FT3 result is the one to look at to know whether you’re on enough thyroid hormone replacement.

What was your FT3 result? Was it high in range?

[shaws Administrator]

Of course your TSH and T4 will be low. After all you are taking a combination of T4/T3 when the blood tests were introduced along with levothyroxine alone i.e. T4.

Taking 50mcg of T3 - equal 'in its effect' to 200mcg of levothyroxine your TSH and T4 will be low.

The doctor should concentrate more upon any clinical symptoms you have and relief of them.

How 'do you feel' on your combination - are your symptoms resolved or nearly resolved.

Researchers have shown that combinations of T4/T3 should be 3:1 or 4:1 and works well for the patient.

[Batty1 in reply to shaws]

Shaws, do you have a breakdown list of what each mg of T3 equals to T4 meds? Your the first post I actually seen with 50mg t3 =200 levo.

[SilverAvocado in reply to Batty1]

There are very different estimates of the different potencies of T4 and T3, in journal articles I have seen suggestions that T3 is up to 10x more potent than T4!

I think about 3x-5x is more reasonable. I've aways used 4x in my dosing, but I've noticed recently that 3x has become more popular on the forum (I am a bit worried my memory is letting me down on that one, I know the forum consensus has not been the same as mine, but I might be remembering it wrong and its 5x rather than 3x. Sorry, not very helpful!!)

In case that isn't clear:

Using the assumption I've dosed on, that T3 is 4x as potent, would mean 5mcg of T3 is roughly equivalent to 20mcg of T4.

Using what I think is more popular on the forum, that T3 is 3x as potent, would mean 5mcg of T3 is roughly equivalent to 15mcg of T4.

Oops, I pressed SEND too soon... I'll continue below.

[SilverAvocado in reply to SilverAvocado]

Using these equivalencies you can, e.g. estimate the rough equivalent dose of a grain of NDT:

If one grain contains 38mg of T4 and 9mcg of T3.

Then the roughly equivalent T4 would be: 38mcg + (9mcgx4) = 38mcg + 36mcg = 74mcg of T4

And the roughly equivalent T3 would be: (38mcg / 4) + 9mcg = 9.5 mcg + 9mcg = 18.5 mcg of T3

This is using my own preferred potency estimate of T3 being 4x more potent than T4. You can see that if you assume 3x or 5x or something else you end up with a bit of a different estimate.

It's important to remember that there is no true equivalency. If your body can't make good use of T4 then no amount of T4 will be equivalent to a little bit of T3. Or if you get a bad reaction to one of them, or need whatever is different in NDT to feel well, or all the tiny differences in everyone's gut function, remaining thyroid function, conversion effectiveness, HPA axis, etc, etc, etc.

These are just estimates we can use to juggle a dose or swap things across, but they should always be treated with caution.

One other little wrinkle, I think doctors tend to see T3 as greater in potency, and patients tend to see it as lower in potency. A cynical mind might say this is so doctors can get away with giving tiny T3 doses or stealth reducing patient's doses when they add in T3.

[shaws Administrator in reply to Batty1]

I have read that 25mcg of T3 equals (in its effect - approx) 100 mcg of levothyroxine. If you're in the UK, NHS T3 is 20mcg I understand.

[Batty1 in reply to shaws]

You wouldn't happen to know what it is for 5mg ? I cant find anything.

[SlowDragon Administrator]

Does your GP actually know you are self medicating T3?

On almost any dose of T3, TSH will be extremely low. As you are taking 50mcg T3 that's pretty much a full replacement dose

Are you currently taking any Levothyroxine?

Most important result is FT3

What was FT3 result?

What about vitamin levels?

For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also important to test vitamin D, folate, ferritin and B12

When were vitamin levels last tested?

What vitamin supplements do you currently take?

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and fasting. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

Last Levothyroxine dose should be 24 hours prior to test, (taking delayed dose immediately after blood draw).

when also on T3, make sure to take last dose 8-12 hours prior to test, even if this means adjusting time or splitting of dose day before test

Is this how you do your tests?

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or all vitamins

thyroiduk.org.uk/tuk/testin...

Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have special offers, Medichecks usually have offers on Thursdays, Blue Horizon its more random