Free t3 levels: Hi, This is my first post, been... - Thyroid UK

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Free t3 levels



This is my first post, been lurking for awhile reading and trying to learn. Im going I can bet some help figuring out if my free t3 level is optimal.

My last free t3 was back in April 2017.

Free t3 289 Ref range 222-383

free t4 1.1 Ref range 0.8-1.6

I can't seem to lose weight at my current dose. I take 137/150 levoxyl and 10mcg cytomel.

Cutting calories didn't work as I learned awhile ago and exercising just makes me fatigued. I had rai 19 years ago with some working thyroid left. 3 years Ago i think my thyroid fianlly gave out what little I had left.

I saw my doctor yesterday and had argued I needed to count calories and raising my free t3 is it the answer. I need some



16 Replies

You doctor has to learn what burns calories, not count them. Tell him this:

Calorie counting doesn’t work in the long term because calories have different metabolic influence depending on their source. Nutrients also have varying thermic effects that affect their caloric impact.

One of the keys to long-term weight management is healthy metabolism and mitochondrial function, and many diets actually create more dysfunction rather than correcting it. T3 gives raises meabolism so yes

It's ok that your T4 is a little low but your FT3 needs to improve.

Dave, do you want to start from square one? Do you have Hashimoto's determined by antibody testing which means you have an autoimmune disease. We've learned a lot lately about how to tackle autoimmune conditions that may make a difference.

Hidden in reply to Heloise

My doctor told me to up my cytomel yesterday by 2.5 mcg And lower my t4 to 137 instead of alternating 137/150.

I get anxious easily so it's not easy for me to go up on t3. Today I had a higher pulse of 100, I took 7.5 mcg cytomel this morning with my t4 and the other 5mcg 3 hours later. Maybe I should space it out more?

I told my doctor that the calories in calories out is flawed from what I've read. she just looked at me as if I'm stupid. She thinks I should track my calories but I know that didn't work before, in fact it stressed out my body. I don't talk diet or nutrition with my doctor anymore. It's like talking politics.

I had graves when I was 18 and had RAI which left some thyroid tissue and was only on t4 for years.

Should my free t4 be at the top range.

Heloise in reply to Hidden

Dave, you know when your body doesn't have enough thyroid to go around, your adrenals have to step in. They use cortisol and adrenaline. Do you suppose the adrenaline is possibly raising your pulse?

You need more hormone and some say not to separate the dose. others say to split the dose so it's more like your body would do it naturally but I'm not sure I agree because your real thyroid would deliver hormone to your bloodstream and a tablet form of thyroid goes through your stomach to your liver. I don't see how that equates.

It's recommended to get levels to the upper third or quadrant. You definitely need more T3 one way or another. You meant your doctor said that T3 is not the answer, I think.


Heloise, my doctor thinks raising my t3 will not equal weight loss and that it's consuming less calories that will do it. Obviously we don't agree. I hope to prove her wrong.

I'm hoping the 2.5 mcg cytomel bump will help me.

im not sure if it's adrenaline and cortisol that's raising my pulse but I'm better now. I used a little magnesium spray and that helped calm me down. I have anxiety so it doesn't help the situation.


Are you sure that's a Free T3? It's a very strange range. Where do you live? If it's a Total T3, it doesn't give you any useful information.


GG, I am in the US.

Free T3 Value 289 Ref Range 222-383 pg/dL Final

guysgrams in reply to Hidden

bitedust, where in US? I have my FT3 labs done quite frequently this past year or two and have never seen that range and I've used several different labs.

Hidden in reply to guysgrams

guysgrams, I'm in California. My doctors office has its own lab maybe that's why the tests don't seem familiar.

helvellaAdministrator in reply to Hidden

A typical range for Free T3 might be 3.0 to 7.0 pg/mL

There are 100 mL in a dL. So using the same units, that would be 300 to 700 pg/dL.

222 to 383 is a surprisingly narrow range.

(That it is a bit lower than many is quite likely just part of the inconsistency of tests.)

I do wish we all used the same units! I struggle to understand why they use the non-standard decilitre! I also struggle to understand why we see the USA (in particular) sticking with weights rather than molar units.

Hidden in reply to helvella

My doctors office must use some in house type of lab that's out of the ordinary because I've been to other doctors in the past who send out their labs and the tests were similar to this type- 3.0-7.0 pg/ml. I raised my cytomel by 2.5mcg 2 days ago and it did not agree with me.

What's funny is I took 1000mg of vitamin c yesterday and that gave me such a boost of energy throughout the day and couldn't sleep that night. That did way more for me than the cytomel bump did 2 days ago so I'm thinking its certain nutrients I'm missing in my diet. I do though have been eating lots of watermelon and some strawberries but I guess that's hardly enough vitamin c to make a difference. I noticed also my stress level went down so maybe I had high cortisol and adrenaline.

guysgrams in reply to Hidden

bitedust, must be as I live in AZ and never have seen those kind of ranges. :)

Hidden in reply to guysgrams

I need a new doctor and


Levothyroxine is known to cause weight gain! Usually it is due to being given too low a dose to enable our metabolism to increase.

I have read that a combination should be 3:1 and go to page 80 and top left hand para to read.


Thanks shaws, I will check it out. I tried to increase cytomel but it seems it's making my pulse go over 90 and more anxiety.

Maybe I have some nutrient deficiencies?


Shaws, you're saying I have to switch to ndt to lose weight. I have tried armour before and it did not work for me, to much t3 in it, made me feel bad.

Dave, that is not a Free T3 result. That is a Total T3, which tells you nothing. You need an FT3 before we can tell you anything.

But, certainly, eating too few calories in not a good idea when you're hypo. It impedes conversion and has the opposite effect. Even though you're now taking T3, it's only a tiny dose, so you do need to be able to convert some of that T4.

Never, ever discus nutrition with a doctor, they don't know the first thing about it!

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