Thyroid UK
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How long for levo decrease to reflect in bloods

Hi really sorry for all the posts lately just feeling stressed and a bit lost.

As I posted earlier I increased my meds for 1 week from 88.5mcg(alternate 75/100) to 100mcg after getting blood results that showed I needed it. I assumed my gp would increase it any way and I couldn't get in to see her for a week. She then refused to increase it until I've seen an endo which is a 16 week wait. I reduced back down and took 75mcg yesterday (felt like crap all day and napped straight after work) and haven't yet decided if I'm going to take 75 or 100 tonight.

I'm thinking about going to see an endo in the department I've been referred to privately as she can fit me in within 4 weeks.

However I'm worried if I do it too soon my bloods will reflect the increase dose and not be accurate.

I know with a dose increase its usually 4-6 weeks so do you think it won't have made a difference yet? Or should I wait 4-6 weeks?

Thanks for all your help

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However I'm worried if I do it too soon my bloods will reflect the increase dose and not be accurate.

Yes they will, they will be accurate for the dose you're taking.

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Thank you

But from when?

I took 88.5mcg (alternate 100/75) from 26th Jan to Monday 12th March.

Had the blood test then took 100mcg from Tuesday 13th March - Monday 19th March. Then took 75mcg yesterday.

I now have to go back to taking 75/100mcg alternately until my endocrinology appointment.

So will the temporary increase to 100mcg have effected my bloods already?

I need them to show my levels on 88.5mcg for the endo blood tests so she can recommend my gp to increase because that's what my gp is keeping me on. If she sees my levels from the 100mcg when I'm on 88.5 she wont think I need the increase x

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I very much doubt it will, no. Such a tiny increase for such a short time. The TSH doesn't respond that quickly, and that's all they ever really look at. When are you planning to have these tests?

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Thank you. It would depend if I decide go private or not.

If I do my appointment will be in 4 weeks so will do the test in about 3.

If I don't I've got atleast another 9 weeks to wait possibly another 16

I was just asking to help make my decision because if I had to wait another 6 weeks again before retesting then there possibly wouldn't be much point going private

I don't want to spend the next 9-16 weeks getting worse on an inadequate dose but then don't want to spend £200-£350 on someone to just say yes increase Levo now because it isn't exactly specialist. Not like I'm going to be considered for t3 or anything because I'm not on a high enough Levo dose yet x

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OK, difficult decision. And, I honestly don't know why your GP couldn't put your dose up. It's not exactly rocket science! But your labs should be ok in three weeks, despite the brief increase in dose. So, you don't really need to use that to make your decision.

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Thank you that's exactly what I needed to know :)

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It takes two weeks to show the change of dose in the bloods. Hope that helps

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Hi ...first time I have posted on this brilliant site. Yes the levels of thyroxine should stay stored for up to 2 1/2 weeks

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Thank you. So if I was only on the increased dose for a week will it not show?

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You won’t get an accurate result as it takes at least two weeks. Two weeks is enough though so don’t worry too much.

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Also, if you feel you need to increase the dose the best thing to do is to make sure you take all your supplements at the right time in the day for example take zinc and selenium an hour after you levo and then four hours later take calcium and iron. These will help the levo which is T4 to absorb better and also convert to T3. Which is what it supposed to do.

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How long have you been on thyroxine?

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Welcome :) Have been on thyroxine since March 17 started on 25mcg and gradually increased to 88.5mcg. Then had the one week of increase to 100mcg but have to come back down to 88.5mcg until an endocrinologist approves the increase back to 100mcg x

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The rule of thumb is to hold on a steady dose for 6 weeks, and then take a blood test.

You're talking about 6 days on a slightly higher dose, and then a blood test 3 weeks later? I'd say that won't make a huge difference, and in fact you don't need a completely accurate test anyway, because your numbers are already very far from ideal. I'd say it would take a few doses to raise them.

Seeing your situation laid out as you did in the original post, I'd be tempted to wait for the longer away Endo appointment, increase to 100 mcg yourself, take the new blood test with that dose, and go in to discuss that one. You will likely still be undernedicated, and will be going in with the question of whether you can stay on that dose OR raise it further. You'll be one step further along, and hopefully the Endo will raise you further. There's a small chance the Endo will be terrible, and not want you to stay on 100. But there's a chance the Endo will be terrible anyway!

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You can also go in and say you feel tons better with the raise!

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Thank you! I would prefer to do this but unfortunately my gp won't give me any more medication so I wouldn't be able to increase to 100 without trying it.

I've found a recommended endo who can fit me in next week. So maybe o could use the same bloods I had done on 13th March?

I could then keep my longer nhs end referral for possibly another increase from 100mcg.

Ideally though I want to have my nhs ultrasound before I go. So I'm considering waiting for that?

My PCOS ultrasound took 11 days from day of referral to results with my gp.

But this time she did say it would take about 2 weeks for them to get the results. Either she was just preparing me for worst case scenario or it's more specialist and takes longer? X

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I'm afraid I don't know anything about how to balance it all with PCOS testing.

It is possible to buy your own Levo to top up, but that moves into the world of self medicating.

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