Thyroid UK
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Hypo thyroid Drugs raise Blood Sugar by 10-20 points


I have noticed that Hypo thyroid fixing drugs like Levothyroxine, Thyronorm etc raise the fasting, random and post prandial blood sugars as much as 10-20 points.

I had to stop all thyroid medication due to my personal testing of the sugar levels raising and reminding high for a long time ( Insulin resistance). Try to stay away from Thyroid medications as long as you can.



8 Replies

Welcome to the forum, Jayerramilli.

If someone is hypothyroid and has insulin resistance they will require treatment for both. When diabetes or hypothyroid medication are adjusted both blood sugar levels and thyroid levels should be checked in case further adjustment is required.


I don't think I have insulin resistance as my fasting sugar is 85 and HbA1c is 5.2 .Thyroid drugs cause elevation in Blood Sugar and the doctors and pharmaceutical companies need to tell the patients that. I have blood work reports to prove this. If I dont take levothyroxine my fasting BS is 85, If I take it it is 95- 100. Why does thyroid drug raise BS like that and why dont the Dr;s and pharma companies tell us that?

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If you Google "Levothyroxine + diabetic" or "Levothyroxine + Blood sugar levels" you'll see that it is common knowledge that Levothyroxine can raise blood sugar levels.

The Levothyroxine patient information leaflets I've read advise diabetic patients and patients using insulin to consult their GPs when taking Levothyroxine.

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If a thyroid medicine like Levothyroxine can push the blood sugar levels to abnormal levels and make a non diabetic person, diabetic just by taking a thyroid medicine, shouldn't the doctors tell the patients that before giving it? and then they want you to take the medicine for life, so thereby making a normal person diabetic because of this medicine!


I was always wondering this as I am sure my NDT have some sort of sugar or glucose binding in them. I take them at night but my blood sugar is always slightly over on my fasting result in the mornings.


When diagnosed hypo I was told I was not diabetic, twelve months later I was. Three months after that by diet I was back to the start point. Now due tests and have put weight back .......

So I had put my weight and eating habits as the cause of my Type 2 diabetes .I still think it is the case but perhaps the levo took me nearer .


Well, people with high TSH need to monitor their blood sugar levels and Lipids ( Triglycerides ). You should also keep checking your Blood sugar using the personal Blood Glucose meter. Before starting the drug my FBS was 85 which is perfectly normal and after taking the medicine it shot to 95. I stopped the med and now its back to normal limits. Can we report this to the FDA or some health agency? I cannot believe a non diabetic becoming diabetic because of thyroid medication!

No doubt once you have high TSH ( mine is 8.5 ) you need to cutdown sugars, carbs and work out atleast 40 minutes each day!


My TSH was 101 when diagnosed.Last June below 1 .Have cut carbs ,especially cakes and scones .But at 72 my work outs are confined to a three mile walk most days and occasionally up to six miles. Mind you I was never in to work outs.


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