Thyroid Function Test following weight loss

A few months ago I was diagnosed prediabetic. I was over weight and on 125gm of Levo to control Hypothyroid. I decided to lose weight to control prediabetic. I lost 23kg over 4 months. This week I had my blood test and my readings were:

TSH :< 0.05 (range:0.35 - 5.5)

Free T4: 24.7 (range: 9-22.7)

Free T3: 7.6 (range: 3.5 - 6.5)

Four months ago, the results were fine.

The doctor has recommended that I should lower my dosage of Levo from 125gm to 100mg for a month and followed by reduction to 75mg.

is this right course of action?

17 Replies

  • You are lighter now, so need a lower dose to achieve the same result.

    Well done you!

  • I can't help feeling that that might be too much of a reduction. If it were me, l would want to reduce to 100 for six weeks, then test before reducing again. Because, if it is too much, you might have trouble getting him to increase it again.

    Do you have Hashis?

  • Thanks for the suggestion about not reducing levo too much.

    No I don't have Hashish.

  • OK :)

  • Hashis. ie autoimmune antibodies. Not Hashish!!

  • Lol. I know. :)

    Just to clarify, I don't have either!!

  • Ahsank Personally I would have thought a reduction in meds then wait 6-8 weeks and retest before deciding whether to adjust meds again. And as you're only slightly over range I would want to try a 12.5mcg reduction rather than 25mcg.

    Very well done on your weight loss.

  • I'd do as both @greygoose and @SeasideSusie suggest, reduce slightly at first and see how you feel. Doctors are apt to take more notice of the blood tests than the patient's clinical symptoms. Doctors are only interested in keeping the TSH in a range even if its at the top when our aim is around 1.

    You have had great success in your weight loss so it is more important you feel well than dropping dose so much that you'll have other clinical symptoms.

    If you do as SeasideSusie suggests and if you feel well don't be persuaded to lower it again as your frees are just outside the range.

  • Thanks. The reason I posted in the first place is because I had doubts with what was suggested by the doctor. Not too bothered with T4 and T3 reading slight on higher side of the range but having TSH so low is something that is concerning me as to what long term effect it might have on me.

  • The Thyroid Stimulating Hormone i.e. the TSH is from the pituitary gland and its job is to rise if thyroid hormones are reducing to such an extent. Doctors frighten us with wrong information in that we'll have a heart attack etc if TSH is very low but people who've had their thyroid gland removed completely are given doses to suppress their TSH and they don't come to any harm.

    Doctors who practiced before the blood tests and thyroid hormones, prescribed NDT until patient was well. No blood tests no ranges - only Natural Dessicated Thyroid Hormones. No heart attacks or other problems. About ten years later after the blood tests etc were introduce new diseases were named i.e. CFS, and Fibro and ME.

  • I have had a similar experience though only lost 15kg and was diagnosed diabetic not prediabetic. My TSH was also 0.05. I was on 125 mg Levothyroxine. First reduction was to 100mg every other day with 125 on the alt day. Went up to 0.09 in 6 weeks. Then reduced to 100mg every day. Retest this week(6 weeks later) shows TSH now at 0.6. So in range but currently feeling symptomatic of undermedication! My GP didn't test T3/T4

  • The TSH is useless as we can have a very low but some doctors are happy somewhere in the range, even the top and that doesn't help us one bit. We need it around 1 or lower.

    The normal test is usually TSH and T4. I have no idea why they don't test FT4 and FT3 at least occasionally.

    We had quite a few doctors who agreed with Dr Derry, as well as many patients.

  • I would get a test after first reduction that might well be your preferred level and see how your body is reacting to that. May be if then some mileage in dropping down again then try alternating them for a while first.

    Very well done on the weight loss!

  • Hi Ahsank. I have also been told I'm prediabetic (also have Hashimoto). Has the weight loss had an effect in your prediabetes diagnosis.

  • Yes, the weight loss appears to have reversed it.

    The reading for the average 2-3 months (HbA1c) test in August was 47 mmol but now is 40. The normal range is upto 42. So still at the high end but within the normal range.

  • Thanks that's good news and well done, it's not easy to lose weight when you're hypo. I plan to get on with the weight loss and exercise in the new year.

  • Give up sugar, bread, pasta, rice and potatoes. It will help with the weight loss.

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