Dose guide of levothyroxine : If my weight 63kg... - Thyroid UK

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Dose guide of levothyroxine

tamina786 profile image
28 Replies

If my weight 63kg how much levothyroxine I need

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tamina786
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28 Replies
Lalatoot profile image
Lalatoot

It depends on how you take your levo and what your blood results are.

greygoose profile image
greygoose

Doesn't matter how much you weigh, the protocol is - or should be - starting low (50 mcg) and increasing by 25 mcg every six weeks until you get to the dose you feel well on.

Dose by weight is for people who've had a TT, as a starting dose. It is then adjusted up or down, after six weeks, as needed. It's not a reliable way of dosing for people who still have their thyroid.

tamina786 profile image
tamina786 in reply togreygoose

I had near total thyroidectomy so how should dose my self cause GPS are making hyper then hypo

greygoose profile image
greygoose in reply totamina786

So, I'm guessing that they are dosing by the TSH?

They can't make you hyper, but they can over-medicate you. To avoid that, you need your FT3 tested. You are only over-medicated if your FT3 is over-range. That is the most important number.

What were your last results (with ranges)? How much levo are you taking?

tamina786 profile image
tamina786 in reply togreygoose

Tsh 0.01 t4 12

Lalatoot profile image
Lalatoot in reply totamina786

Tamina It is FT3 that is the most important result. It is FT3 that your cells use and it is too much or too little of it that gives us many of our symptoms.

To be able to adjust your dose or to see where problems are you really need to have TSH, FT4 and FT3 blood tests done at the same time. Your last dose of levo should be 24 hours before your test.

You need to have vitamins tested too as they need to be at the best levels for the medication to work.

SeasideSusie profile image
SeasideSusieRemembering in reply totamina786

As requested by Greygoose, reference ranges are needed tamina786 to be able to interpret your results. They vary from lab to lab so we must have the ranges that come with your results. If you have online access to your results you should be able to see the ranges as well, if you don't have online access then ask the receptionist at your surgery for a print out, the ranges will be on that.

greygoose profile image
greygoose in reply totamina786

How much levo are you taking?

Rosie2m profile image
Rosie2m

If I am correct (and I may not be) the new nice guidelines suggest starting levo at a dosage of 1.6microgram per kg of body weight, rounded to the nearest 25microgram and then adjusted accordingly following test results, as I say I could be wrong as this is all very new to me x

Carysta profile image
Carysta in reply toRosie2m

I have read this too

helvella profile image
helvellaAdministrator in reply toRosie2m

They do. And, in my opinion, it is one of the things they get wrong.

If I were dosed at that amount, I would be substantially over-dosed.

My take is that there is a fundamental misunderstanding - by the guideline writers.

1.6 micrograms per kilogram might be around what most people need in order to be a full repacement dose - for example, after a total thyroidectomy. But if we have any remaining thyroid function, we do not need that much. And if we do not absorb the levothyroxine, we might well need more.

So starting everyone on 1.6 micrograms per kilogram is inappropriate.

Rosie2m profile image
Rosie2m in reply tohelvella

I agree, I don’t think I would need what my dose would work out to using that method either, I’d be happy to just have a slight increase but these guidelines do mean I have something in my arsenal to help with my argument if they try to fob me off again ;) x

helvella profile image
helvellaAdministrator in reply toRosie2m

That is a rational approach.

So don't expect it to work. :-)

Rosie2m profile image
Rosie2m in reply tohelvella

True! I’m just hanging on to threads of hope here lol x

AlasdairM profile image
AlasdairM in reply tohelvella

As a ball-park 'starting guide', remember it's lean body mass, not total weight - an estimate of percentage body fat needs to be subtracted from your scales' reading - fat cells are inactive. Even a lean healthy person may be 15% body fat - not all fat is bad 😊

helvella profile image
helvellaAdministrator in reply toAlasdairM

That is, indeed, what has in the past been said. But there is nothing in the NICE NG145 guidleines which says that. (Unless I missed it!)

AlasdairM profile image
AlasdairM in reply tohelvella

NICE guidelines are a poor source of explanation, being for 'informed' medics. It is what two different consultants did for me (10 and 8 years ago) - they had scales with metal contacts under your feet to estimate fat %.

For me, I don't convert well, guide gives number 12.5mcg less than I need to function properly.

Batty1 profile image
Batty1

I never understood the weight thing for T4 meds I read it all over the place but not once has any Endo dosed me based on my weight .

helvella profile image
helvellaAdministrator in reply toBatty1

Once people are on a dose, almost any dose, it would seem more sensible to adjust on the basis of a combination of how well the person feels and blood tests - not some "look it up in a table" basis.

Referring back to this mythical standard dose can help to identify people who are taking much higher or lower doses - which could have some use.

Batty1 profile image
Batty1 in reply tohelvella

I have read about it but my Endos never used that method for dosing me which might explain some things

vocalEK profile image
vocalEK in reply tohelvella

If you had Type 1 Diabetes, the endos would not dream of setting your insulin dose based on a "standard" dose or by weight.

Eliotf profile image
Eliotf

Most of your dosage is how you feel, then add the blood tests of all tests: tsh, ft3, t3, ft4, t4. Grey goose has very good knowledge

Eddie83 profile image
Eddie83

The rule of thumb is that the "full replacement" dose of levo is roughly 1.5-1.7 mcg/kg body weight. So if you are an easy-to-treat patient, your daily levo dose should be in the range 94-107mcg. However, depending on other factors (do you have Hashi's? is your T4->T3 conversion poor? do you have critical nutritional deficiencies? etc.), you could need something other than the levo "full replacement" dose. Keep in mind that the dose you need is the one that makes you feel well, and not the one that the doctor dictates to you as the result of a lab test.

tamina786 profile image
tamina786 in reply toEddie83

Hey so if I weigh 63kg what amount of levothyroxine I will need because no one is getting my dose right from 75 levothyroxine to 100 then even adding t3 but I'm not getting no luck and an so unwell please if you need to know is it by weight or lean weight

Eddie83 profile image
Eddie83 in reply totamina786

If you have used levo in the 94-107 mcg range, and added T3 but still don't feel well, chances are you have other problems. Thyroid treatment is a minefield for many patients, because there are so many problems that contribute to thyroid replacement not working. Do you have the TPO or TG antibodies that prove you have Hashimoto's? Has your doctor ever actually measured FT3 to see if you are converting? Has your doctor ever determined if your FT3/rT3 ratio is high enough to show you are not generating excess rT3? What do you know about your nutritional status ... have you had any measurable nutrients such as B6, B12, D3 checked to see if they are in range? Are you taking small doses of selenium (which supports conversion enzymes)? Can you identify what your symptoms are when you are on replacement that is not working? Do you know if you have any food allergies or intolerances? Will your doctor even consider T3-only treatment, even if only temporary, to see if T4->T3 conversion is the problem? Is your doctor one of those ignorant types who only uses TSH for diagnosis and treatment? It has been my experience that patients who recover from thyroid problems the quickest, often private-pay to see functional medicine docs or naturopaths. It is sad, but most GPs, and even many endos, don't have the training and experience to treat thyroid patients who have "edge" cases. In my case, it took me 21 years (yes, twenty-one years) to get to a state of feeling fairly well, AFTER I got off the gluten that was poisoning my system. It shouldn't take that long, but unless you can get access to a practitioner, or helpers on a health board like this one, who actually know what they are doing ... it might take that long.

Eddie83 profile image
Eddie83

OOPS! I didn't realize you are a Graves patient. I have no direct experience with Graves, and much of what I said is not applicable to you! This board deals mainly with hypothyroidism. Given that there are hundreds of youtube videos about Graves, it seems to me there is probably a specialty board somewhere which deals with the problems caused by TSI antibodies. What is your antibody score?

tamina786 profile image
tamina786 in reply toEddie83

I had graves disease but had near total thyroidectomy

Eddie83 profile image
Eddie83 in reply totamina786

So far as I know, thyroidectomy does not get rid of Grave's antibodies. If Graves is like Hashi's, just the presence of antibodies can prevent people from feeling well. Have you had a recent TSI test to determine antibody level?

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