Low free T4, TSH and T3 mid range: Should I... - Thyroid UK

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Low free T4, TSH and T3 mid range

Should I increase Synthroid (50mg) and T3 (15mg)?

I can post exact results soon … at the Doctors office now and hoping to guide her in the right direction.

10 Replies


You've not given us sufficient information. If you feel well there is no need to increase dose but if you are still symptomatic then there may be scope for increasing dose. Most people feel well with FT3 in the upper third of range.

in reply to Clutter

Thank you. I’m sorry for not posting all the pertinent info. I was in a bit of a panic sitting in the doctors office.

Clutter profile image
Clutter in reply to


No need to apologise. I was just advising why we couldn't help much without more information. Free T3 is low in range so you could increase Liothyronine to 20mcg or 25mcg. It will suppress your TSH though.

VitD is optimal 50-60 ng/ml. I would supplement 5,000iu D3 for 6 weeks and then reduce to 5,000iu alternate days and retest in March. VitD should be taken 4 hours away from thyroid meds.

B12 and folate are good.

I can't see why your GP wants to check pituitary. Most people feel well when FT3 is in the upper third of range.

in reply to Clutter

Honestly, I think she is just puzzled by the numbers and trying to cover her bases. I have only gotten the Liothyronine added to my prescription because of the information I have received on this site.

I feel fortunate that this doctor will at least entertain the notion of adding Liothyronine. Up til now, all other doctors would not … Levothyroxine only 🙄

My sincere apologies. I should have waited to do this properly.

I am currently taking 50 mg of Synthroid and 15 mg of Liothyronine.

I feel just “okay”. I have gained weight (10lbs.) and certainly not the energy levels I would hope to have.

Here are my latest results:

Free T4: 0.69 (0.82-1.77 ng/dL)

TSH: 0.149 (0.450-4.500 ulU/mL)

Free T3: 2.9 (2.0-4.4 pg/mL)

Vitamin D: 36.3 (30.0-100.0 ng/mL)

Folate: 12.9 (>3.0 ng/mL)

B12: 1059 (211-946 pg/mL)

Doctor recommended that we run some pituitary blood work to see if there is a possibility that it might be the problem.

greygoose profile image
greygoose in reply to

You're under-medicated. Why would he think the pituitary was the problem? He just needs to increase the T3.

in reply to greygoose

Thank you for your response. She (the doctor) thought that because all numbers were low or at the low end of the range that it could be pituitary related. She did not change anything dosage-wise until we complete this blood work - which I will do tomorrow. Honestly, I trust the information provided on this site more than any doctor I have had in the past.

greygoose profile image
greygoose in reply to

It would have been a pituitary problem if, before diagnosis, your TSH had been low, and your Frees low. But, once you start on thyroid hormone replacement - especially taking T3 - the TSH is low because you're taking thyroid hormone replacement - especially taking T3. She's got things a bit upside-down and the wrong way round. You just need and increase in T3.

in reply to greygoose

Thank you for the explanation. Every tidbit helps me learn more.

greygoose profile image
greygoose in reply to

You're welcome. :)

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