Hi all, I’m diagnosed hypothyroid with TSH 3.65, normal free T3 but low free T4. I’m on 100mg of thyroxine but I feel that I have been gaining weight despite initially losing some when I started thyroxine. Also, I have insulin resistance and might need to start on metformin.
Any advice?
Without supplying ranges, it's hard to be specific, but generally a TSH of 1 or below, seems to be the aim. On 100mcg thyroxine, I wouldn't be at all happy with a TSH of 3.65. Both FT3 and FT4 are usually better in the upper quadrant of their ranges. "Normal" free T3 is too vague, I'm afraid.
If you DO begin metformin, many medics forget/don't know that it affects the pituitary/hypothalamus axis and can make the TSH appear suppressed.
It's (even more) essential to dose levothyroxine by the free T4 and free T3 and NOT the TSH level, when a patient is taking metformin.
If you are gaining weight, maybe your freeT3 and FreeT4 levels are not optimal for you. And I would want my TSH much closer to 1.
Thank you for taking time to reply. My FT4 is low. FT3 is normal.
Do you suggest that I ask for an increase in thyroxine? I’m just concerned that I’m not converting well and that this dosage is resulting in higher reverse T3, which can mimic hypothyroid.
Thank you.
A low FT4 would suggest that you could tolerate an increase in levo. That should also bring down your TSH.My understanding of reverse t3 is when you have high FT4 which isn't being converted to T3, but your FT4 is low, so I wouldn't have thought you needed to worry about reverse t3.
That makes sense. Thank you for explaining.
By the way, I just realised I need to clarify something - my TSH was 3.65 and my FT4 was low. I also tested positive for insulin resistance. I have then been put on thyroxine of 100mg but I’m not sure if it’s working. I feel like I’m gaining and not losing weight. My feet are cold too and my memory seems to be less sharp. My doctor (GP) told me he might add metformin for the insulin resistance.
I will be having a new round of tests soon and will see if my TSH, FT3 and FT4 have changed.
Looking at previous posts
Probably not in U.K.?
Please add country in profile
Extremely low vitamin D in previous post
Low ferritin too
Presumably now on vitamin D supplements
Retest twice year
Work on increasing iron rich foods in diet for low ferritin
Have you had B12 and folate tested
How long have you been on 100mcg levothyroxine
Did you get thyroid antibodies tested to confirm autoimmune thyroid disease also called Hashimoto’s
Have you had coeliac blood test done
Are you now on strictly gluten free diet
For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested.
Also EXTREMELY important to test vitamin D, folate, ferritin and B12
Low vitamin levels are extremely common, especially with autoimmune thyroid disease (Hashimoto’s or Ord’s thyroiditis)
Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .
Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).
This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)
Is this how you do your tests?
About 90% of all primary hypothyroidism in Uk is due to Hashimoto’s. Low vitamin levels are particularly common with Hashimoto’s. Gluten intolerance is often a hidden issue to.
Link about thyroid blood tests
thyroiduk.org/getting-a-dia...
Link about Hashimoto’s
thyroiduk.org/hypothyroid-b...
List of hypothyroid symptoms
Do you have PCOS ?
I have insulin resistance 
Common to have insulin resistance with PCOS
helloclue.com/articles/cycl...
Vast majority of primary hypothyroidism is autoimmune thyroid disease also called Hashimoto’s
PCOS and Hashimoto’s often go together
pcosdiva.com/2015/08/got-pc...
Thank you but I don’t have PCOS though, nor do I have Hashimoto’s. I do have hypothyroidism and insulin resistance (maybe pre-diabetes)
Hi I hope my information is helpful. On you second point, it is totally possible to reverse your insulin resistance with a diet change and many have done this successfully,do not feel resigned to taking medication for life unless you want to of course. Low carb/Keto diets very successful at turning this around. Recommend a consultation with Roderick Lane who is a Naturopathic Dr and an expert in Endocrine issue .
Thank you!
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