Levothyroxine worry

[Goldengirl69]

Hello all, I've been underdosed for years on Levothyroxine. If its OK, can anyone tell me what dose they are on. So I can get a rough idea , as doctors are neglecting me. Also can you tell me ur height and. Weight. I'm in dark place , and really need help . This would help lots .thankyou .

[TiggerMe Ambassador]

As a rough guide 1.6mcg x weight in Kgs = dose T4

[Goldengirl69 in reply to TiggerMe]

Hi Tiggerme, Thanks. But I'm no good at this maths. My weight is 13 stone , can u tell me Possibly what that would be .

[Sparklingsunshine in reply to Goldengirl69]

13 stone in kilos is 82.5 roughly, times that by 1.6mcg and you get a figure of 132. So if dosing by weight you would be aiming for 132mcg of Levo daily. However dosing by weight is only a very rough approximation.

There are many variables, if you are pre or post menopause, how well you absorb Levo, gut function, your vitamin and mineral status, any other medications that might interfere with how well Levo works. Or any other medical conditions you might have. We need what we need to allow us to feel decent.

[helvella Administrator]

I'll be very blunt here - with the intent of helping (not criticising).

You cannot determine levothyroxine requirement by weight. Or weight and height.

Yes - there are formulas which seem to say you can. But there are several reasons you cannot.

For one thing, no-one can be sure how much levothyroxine they absorb. Maybe you absorb 60%? Or 70%? Or 80%? - of whatever you take. That makes it quite a wide range.

For another thing, maybe you absorb one make better than another?

And maybe one batch is slightly more potent than another.

Weight (and height) can be used to provide an estimate of what you might need if you suddenly lost your thyroid. But it is only a best guess of where to start.

And you can look at a formula and get an idea that a dose is suspiciously low or questionably high. But that only really says you need to check things like blood tests. Not adjust your dose based on a formula.

Best thing you can do is post blood test results you have. And, if affordable, consider getting a private test (which might include more elements than the typical NHS "TSH-only" approach).

helvella's calculation document and spreadsheet can be can be found by following this link:

helvella - Estimation of Levothyroxine Dosing in Adults

A discussion about the use of formulas to estimate levothyroxine dosing. Includes link to a downloadable spreadsheet which calculates several of these.

helvella.blogspot.com/p/hel...

[jgelliss in reply to helvella]

Thank you Helvella for validating my feelings. According to my weight I should be on a lower T4 dose. But I feel my best on a higher T4 dose with a small T3 added to the T4 mix. I had TT and Dr's can never dose me the right way for "me". Eighther I was over or under dosed. I learned from my thyroid journey that I was the best rat lab for myself. You know what you feel and that's cellular results. Lab results are just results of the moment the labs where done. Cellular is by far more telling. Unfortunately there is no tests for cellular. That's why we have to trust ourselves what we feel is what we feel .

[TiggerMe Ambassador]

Have you got some recent results you can share? It's also important to have good levels of B12, Folate, Ferritin and Vit D for T4 to be effective

[Goldengirl69 in reply to TiggerMe]

Sorry no, the doctors are disgusting here. They don't care. I asked for my results a few years ago , lots of times to be ignored. The receptionist said she will do them every time and never did. 😪😪I keep meaning to get it done private . But I've been so ill. I hope to soon. Thanks x

[HealthStarDust]

I can offer no advice, but I just want to add I am sorry you are going through this.

I would caution weight and height calculations is not a guaranteed way of assuming what your dose would be. No two exact person will be on the same dose. It’s what happening inside the body, which we know surprisingly little of when it comes to thyroid, is what matters when taking thyroid replacement. When my dose was been based on weight I have been overmedicated.

It’s very much trial and error. But, know I share you desperation in answers and trying an approach that works.

[McPammy]

best thing is get your bloods checked. Then you can take an informed decision on your daily dose.

[greygoose]

Knowing what other people take won't help you in the slightest. Because we're all so different. And we all have different needs. Which is why the protocol for dosing was laid out - although doctors tend to have little idea how that works!

With all hormones we have to start low and increase slowly. With levo that means a starter dose of 50 mcg - 25 mcg if over 65, although that's a rubbish idea! - and increases of not more than 25 mcg every six weeks minimum. And continue like that until symptoms are gone and the patient feels well.

But very few doctors actually do it like that because of their reliance on TSH - which is totally unreliable! The most important number is the FT3, but even that is not always in accord with symptoms and is only a very rough guide. And some people actually need it slightly over-range, which terrifies doctors. In fact, T3 itself terrifies doctors because they don't know what it is.

So, how much levo are you taking now? And when did you last have full thyroid testing: TSH, FT4, FT3, TPO antibodies, Tg antibodies, vit D, vit B12, folate and ferritin?

Oh, and just for the record, myself I'm taking 50 mcg T3 only at the moment. And I have no idea how much I weigh (don't care!) nor even how tall I am - but short! lol And if anybody suggested I should dose by weight s/he'd get the rough edge of my tongue. I haven't had a blood test since 2014 and I dose by symptoms (self-treating) and I'm doing fine, thank you very much! Far better than when I was being dictated to and underdosed by a doctor! But, as you can see, I'm far from typical, so knowing about me is of no help to anyone. You have to find out what you need through trial and error. And, if necessary, give it to yourself and no-longer depend on a doctors gruding charity.

I'll shut up now.

[jgelliss in reply to greygoose]

👏👏👏👏👏👏