Free T3 relevance

Hi, I've just received blood results from the last couple of years and although T4 and TSH are within range free T3 is low. My doctor now says he won't retest as T3 isn't relevant but asked if I'm depressed, lol. I have usual symptoms of tiredness, hair thinning, always cold, loss of libido and super heavy periods and 2 stone weight gain despite always having been thin. Is free T3 really not important?

30 Replies

  • Hi there. If you post your results that you are referring to with the ranges then people will be able to give you more information.

    Your doctor is misinformed, as are most doctors.

    Yes the T3 form of thyroid hormone is the one received by the cells of your body.

    You can have a good T4 and TSh, but a low T3 and be fully symptomatic.

    It make take some time to type out and photofile and add your results here. But it would be worth it to get some reobust opinions.

    PS, just because your TSh and T4 are within range, doesnt mean they are optimal for good health and QoL. So posting your results will be helpful.

    You do have symptoms that are indicative of low thyroid hormones.

  • Thanks for such a quick reply, I will post them when I get home from work. The t3 doesn't seem massively low at 3.3 with an optimal range of 3.6 to 5.5 if I'm correct. I rang this morning and I said I actually do want it tested as if it's consistently low I would like further investigation. The receptionist asked would I like to know the reason if Doc says no, I said no, I'd like another doctor.

  • It's below range!!! Of course that's significant. It should be up near the top of the range. It's low T3 that causes symptoms, not the TSH or T4. Sounds as if you aren't converting very well. But, I will wait to see your full results. Doctors are so ignorant!

  • TcKay,

    FT3 3.3 is below range. I wonder why your GP thinks FT3 test exists if FT3 levels are not important and why there is a range determined if being above or below it is unimportant. It is low T3 which causes hypothyroid symptoms. I felt dreadful when FT3 was below range and well now that is mid range, although many people need it higher in range to feel well.

    Nice riposte about another doctor :)

  • Thanks clutter & greygoose for replies. I'm kind of hoping that it will be in range if I can get it tested as I've adopted gluten free sugar free (pleasure free) diet and started taking b12, iron and vit D to try and feel better. But I think I have a right to know, rather than the stock response of 'are you depressed' because it's cheaper to treat.

  • Did you get blood test to check Vit D and B12 before supplementing?

    Also have you have folate and ferritin levels checked too?

  • Hi SlowDragon, I did get results for those and I'm sure almost everything else was within range. I'll scan and post the page later if it let's me. 😊

  • TcKay, just being in range is not good enough. It's not the same as optimal. It's where in the range it falls, that counts.

  • Ooh, question, how did you get your FT3 levels up?

  • TcKay,

    By adding Liothyronine (T3) to Levothyroxine. I self medicated for 6 months and after noticing considerable improvement in my health my endo prescribed Liothyronine in addition to Levothyroxine.

  • This upsets me.

    My GP lower range in NZealand was 2.5pmol/l and I was 2.6 (in the UK this would have been picked up as below range)

    Then I came to UK and lower end was 3.8pmol/l and i was 3.8 (after two weeks self-treating NDT)

    Then they told me to stop taking NDT as it was dangerous, and then one month after that the lower range dropped to 3.1pmol/l (different lab in UK) and I had dropped to 3.07pmol/l.

    So finally after years of scraping in, I was under someones range, and all of a sudden, there was a healthy action step in me to start taking NDT again. Not sure what the results will be. 1 weeks to go to 6 week test!!

    If I was seeing an integrative/functional GP, the lower limit would have been 4.5pmol/l and this would have been picked up years ago.

    Ho hum!

  • It's a forever moving goalpost. It seems docs don't listen to what patients report and only go by 'range' which leaves a lot of folk feeling rubbish with no reprieve. I did look for NDT but can't seem to source it without prescription. Have you actually been prescribed treatment now, or is that depending on these results?

  • I brought a supplement called Thyrogold from new zealand, which came in the post, and does not require a prescription.

    However, as it is a supplement you do not know how much of whatever it has in it. But it has helped me so far (though not to a level yet that I am happy to settle for).

    There are other non prescription NDTs available.

    Also, there are ways of ordering prescription NDT online.

    If you want help with sourcing you make a new post, or search out an old one and see who can provide the info for you. Please note this will not be posted in a thread. This will be in a private message between you.

    If you are self medicating anything then you have to research the dosing and increments etc etc and get tested every 6 weeks. And know that one NDT may not suit you, but another may. And also that other people prefer levo + lido, or NDT+lido, or lido-only.

    its a process!!


  • Brilliant, thank you, that is so helpful. I will hopefully get a re test but if not then this may be a viable option for me. 😊

  • It needs to be in the top quarter of the range (5-ish) - so under range FT3 is awful and shows that you are either undermedicated on levo (not enough T4 to convert) or you are not converting because of lack of vitamin etc co-factors or a genetic problem (with DIO2 gene).

  • Hi Angel, I'm not taking any meds at all as doc thinks my results are normal and ft3 unnecessary. He has now agreed to retest ft3 on Friday so at least I'll have current results to make my decisions, after lots of great information from you guys here 😊

  • Self medicated how?

  • Oh jeez. I'm sitting here shaking my head so hard it's in danger of falling off.

    T3 isn't relevant??!!??

    What a donkey (and I'm being so very good not to write something very naughty there!). What an utter, useless, twit of a doctor. Another one for the idiot pile, it's growing nicely.

    I despair, I really do, what hope have us thyroidies of ever getting well when these pompous gits don't know half of how the thyroid works.

    I need a shaking head in despair emoticon..................

  • 😂 very well said. It makes me feel like a hypochondriac and that in reality I'm just middle aged and need to verse myself in the science of calories in V calories out.....that's s what the doctor last year said.

  • No wonder so many of us use our GPs for what we need and can get out of them (at my surgery very little actually), then go and do our own thing!

    I did my own testing, found out I wasn't converting very well, so I take my script for Levo and get it filled, source my own T3 to add to it, and ignore their requests for testing at the surgery.

  • You must know an awful lot about the process and that's great to see, but I imagine it comes from the frustrations of dealing with a gp and getting nowhere. I would just like a second test to confirm or deny a problem. This time around it may be normal but the reluctance to test or treat forces alternative measures

  • 40+ years of diagnosed hypo, the last 20+ years not being well but GP and endo not getting to the bottom of it, thinking a non-suppressed TSH is the only thing that matters and lowering your Levo to achieve that regardless of it making you feel like the walking dead and them not giving two hoots.

    Reading, research, learning from this site, lots of private testing to see where the problem really lies. Yes, I've learned a lot and the main thing I've learned is you have to take control of your own health because most doctors don't.

    I just don't understand how, when the knowledge and proof is there, that doctors wont see it. There is the occasional one who thinks outside the box and has an open mind, but that's a very rare animal.

    I know some people do have wonderful, caring doctors. Unfortunately the four at my surgery don't come into that category and have let me down big time and not just thyroid-wise. I am now taking charge of my health.

  • All too scared of losing their licences to practice - their better than average salaries and perks - and perhaps the Title Dr - who knows ? Maybe that is why alcoholism is high among Docs - its the only way they can sleep :-) I believe it is higher with Dentists.

  • The turnover of doctors at this practice has been quite alarming. We're in rural north Wales and not everyone wants to come here, but in recent years we've had 3 nervous breakdowns resulting in the doctors leaving/retiring early, one early retirement (in her 50s and my lovely, understanding GP who I miss so much) and most of them now are part time, just a couple of days a week. Locums are becoming quite frequent.

    It used to be a 4 doctor partnership, it's now known as 'Dr X's practice' so I've no idea if the others are now partners.

    We have a rude one who just sits his side of the desk, doesn't speak when you go in but you may get a 'YES?' out of him on a good day if you're lucky rather than something like 'What can I do for you today?' sort of thing.

    Then another who is so friendly/cheerful/everybody's friend but she's right and you are wrong, and what you're experiencing can't possibly be side effects of the medication she gave you, it's definitely another condition, even though the side effects disappear on stopping the medication.

    The other two aren't quite so rude but not really worth seeing either.

    It's not a vocation any more, so sad :(

  • There is no SCIENCE of calories in v calories out - not all calories are created equal and how many you eat doesn't directly relate to your body composition. There are far more factors - like thyroid, insulin and leptin resistance (or not) and so on.

  • Exactly how I ended up here. It's easy for a doctor to dismiss with the idea that every middle aged woman with weight gain wants to jump on the thyroid band wagon. It comes down again to whether or not they are prepared to listen to what the patient has to say and symptoms they report.

  • Well. statistically, if you have a TSH over about 3.5 you are probably hypo about 80% likely I think, but my maths isn't great. Health people cluster around 1 and there is a long "tail" for the higher values. Your GP probably doesn't even know it's a skewed distribution. If you can get antibodies tested and they are positive, the guidelines say you can get a trial of levo. I'd ask for one anyway or change GP.

  • Ive posted an image of my (broader) results in an new thread as I can't seem to post it as a reply here.

    But, the basics are: TSH 1.78 (0.35-3.5) T4 13 (8-21) fT3 3.3 (3.8-6)


  • Free T3 is the most important one of the lot as it is T3 that you need in all your body's cells - it's the active thyroid hormone - and , as you've fond out, if you FT3 is low, you'll still have hypo symptoms whatever your FT4 and TSH.

    In fact, the depression question is relevant as low T3 can cause low mood - your brain needs lots of it. But the answer is not an anti-depressant, it is to add T3 to your meds, or optimize vitamins and minerals to aid conversion

  • Well most of us on this site think that our T3 result is important. What on earth is the point of having it as a test if it isn’t??! My consultant professor endo thinks that I am “hung up” on knowing what my T3 level is, but has occasionally sanctioned a T3 test. I’ve had others done privately. She is never interested in any results.

    My T3 was always right at the bottom of the range, and it was only reading about it on this site that I realised that it might account for why I was continuing to feel so ill. My endo says that there is no evidence that T3 works, so I’ve bought my own (and still take prescribed levothyroxine), and it has totally changed my life.

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