Having lower TSH levels when taking thyroxine not unsafe, says recent research

(Though this post was first written in 2010, it still works for today and is very pertinent!)

I am amazed.

The Society for Endocrinology in the UK reported that taking higher doses of thyroxine (which will lower the TSH lab result) may be safer than has been purported for decades.

And how low a TSH lab result did they find to be safe? As low as 0.04-0.4, the research found. It’s still safe enough to not cause an increased risk of “heart disease, abnormal heartbeat patterns and bone fractures”, aka HYPERthyroid symptoms.

And those of us worldwide who know about the superiority of having T3 in our treatment (like a working natural desiccated thyroid, T4 with T3, or even just T3-only), can also use these research results in our fight to be on enough with TSH-obsessed doctors. They tend to view research as the end-all to the truth rather than solid clinical presentation, sadly.

Because when we have enough T3 to feel fabulous again with all symptoms removed (in the presence of good cortisol levels, adequate iron levels, B12 and digestive issues), our TSH lab result is always low, aka suppressed, and without one iota of hyper symptoms.

Patients have experientially known this truth about the lousy TSH lab test, without research, for years!

P.S. You WILL feel good most of the time with a midrange free T3, but it eventually backfires. We have to get that free T3 optimal. <—Read the latter.

But here’s what’s missing from their research:

  1. Those “safe, low levels” of an ink spot on a piece of paper do not mean the 16,426 patients they followed will be without numerous issues related to being on a storage hormone alone. i.e. the body is not meant to live for conversion alone! A healthy thyroid will convert T4 to the active T3, but it will also provide direct T3 in addition to the T2, T1 and calcitonin…none of which a T4-only med provides directly.
  2. Additionally, the TSH lab test only reveals the action of a pituitary messenger hormone called the Thyroid Stimulating Hormone (TSH). The lab test does NOT measure whether your tissue is receiving enough thyroid hormone, which is why so many patients on T4 end up with depression, rising cholesterol, high blood pressure, low B12, low iron, and many symptoms, as well as adrenal fatigue thanks to the inadequate treatment of T4.
  3. Raising T4 often encourages an excess production of Reverse T3 over time, which will block cell receptors and increase the very symptoms the researcher state is avoided, as well as far more hypothyroid symptoms.

On the positive side

This is just one more research study that ends up being on our side! i.e. it fits our experiences. I have also included mention of this study on the following page on STTM, where I keep a ongoing list of research which supports what patients already know by their experience and clinical presentation: www.stopthethyroidmadness.com/medical-research/

Important notes: All the information on this website is copyrighted. STTM is an information-only site based on what many patients worldwide have reported in their treatment and wisdom over the years. This is not to be taken as personal medical advice, nor to replace a relationship with your doctor. By reading this information-only website, you take full responsibility for what you choose to do with this website's information or outcomes. See the Disclaimer and Terms of Use.

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40 Responses to “Having lower TSH levels when taking thyroxine not unsafe, says recent research”

  1. Meg

    My tsh has been suppressed for years.. below 0.01 so not detectable. I was on 100mcg t4 and 50mcg t3 with free t4 and t3 in -upper range (17 and 5 respectively) about to start ivf and my ill informed FS wonder do it until my tsh is in range. Even 0.04 as a min she said. I feel ok on 50mcg of t4 but I always tank…. T4 will go down to 7. How can I get my tsh in range for ivf?

    • Janie Bowthorpe

      That is crazy to make yourself undertreated in order to have a procedure. That just underscores how doctors are in the dark ages with their idiotic ideas about the TSH. You’d have to lower the T3, sadly. The TSH is sensitive to T3 in our treatment. And it takes time.

      • Meg

        Thanks for your reply. I made a mistake, I’m on 20mcg of t3 not 50. I have halved my t4 to 50mcg and my t4 is now 7 and my t3 is not 3. I will need to stop my meds 100% for 5 days and then test… hoping my tsh is then in range so I can start ivf. There are implications apparently in the first trimester with suppressed tsh… can cause miscarriage. However I can not find any information on this on the net… I really want to maintain my current meds throughout pregnancy. Are you able to point me in the direction of any info to support suppressed tsh in pregnancy? Feeling distraught.

        • Janie Bowthorpe

          That is absolutely and totally FALSE that “a suppressed TSH” causes miscarriages. Doctors are utterly clueless. Our suppressed TSH is NOT the same as a suppressed TSH from Graves’ disease aka hyperthyroidism. We are NOT hyperthyroid. We do NOT have excess T3 and T4 in our bodies, which is what Graves’ disease causes, and which greatly lowers the TSH. The TSH is just sensitive to T3 in our treatment for hypothyroidism, thus it drops. That is CRAZY that you would be told that. This is an looney tunes issue that we, who have T3 in our treatment for hypothyroidism, face with doctors who DO NOT THINK THIS THROUGH, who fail to ANALYZE what they are told in medical school, in continuing education, and with each other. If Doctors are told that having T3 in one’s treatment will cause our ears to fall off…THEY BELIEVE IT. They are not taught to THINK THROUGH something.

          • Janie Bowthorpe

            You know what causes miscarriages for “some” of us as hypothyroid patients? BEING POORLY TREATED and thus still hypothyroid. Now it’s not ALL of us who see miscarriages when poorly treated. But through the years, there are others who have miscarriages while on Synthroid or any T4-only treatment, which is a POOR treatment.

  2. Melissa

    I gave up on the endo after partial thyroidectomy to remove a nodule that basically looked like an egg on my neck that wasnt much reduced by meds (t4 only). Over the course of a year preceding my surgery i had multiple ultrasounds, at leadt a couple of biopsies, and many blood tests. They told me i had Hashi\’s even though negative antibodies. Said they could tell from U/S. okay fine i accepted that. Post op i got a hold of my surgical pathology report which said it had gone to tumor board. Result said findings consistent with Graves. No idea what to make of that so like a fool i asked the surgeon why the discrepancy when Graves had never even been mentioned in my presence. He told me not to worry about it and that it was probably a mistake. I never said anything. This was the head of endocrine surgery at a major teaching hospital and i was totally intimidated . That was a couple of years ago. Since then my therapist is a nurse practitioner and she\’s been willing to work with me on thyroid meds. She will also run any test i ask her to . So thankful for her. I never went back to aforementioned major teaching hospital. Now I\’m on 150 T4 with 55mcgCytomel split into a couple of doses. I do worry that my prescriber will get nervous because my TSH practically nonexistent and both Ft4 and ft3 at or below the bottom of range. So these are really helful posts. Granted that up until a couple of months i ago i was taking my meds with black coffee.(missed the boat on that one!)i\’m also working on Ferritin and B12. It\’s been a bit of a challenge with the iron as I\’m vegan, but websites and posts like this keep me hopeful and learning. I know my dosing is off, but considering no one paid at the big name hospital paid any attention to my thyroid until my tsh hit 46, i\’ll take my chances doing it this way.

  3. Doaa

    I just want to correct one misprint: the value for my T4 is 0.96. Looking forward to your response.

  4. Doaa

    -Age 44, female, married, 5 children
    -My TSH is 0.012; Free T3 is 3.69; Free T4 is 0.69.
    – I had Ultrasound that shows solid solitary nodule on right lobe.
    – Fine-needle aspiration biopsy conclusion: nodular colloid hyperplasia with cystic degeneration and colloid cyst formation. no atypia or malignancy could be detected.
    -My dr says I need hemithyroidectormy (right lobe), and I agree with that.
    -My questionL is there anything worrying about my TSH, FT3 and FT4 values?
    Thanks a million for your response

    • Janie Bowthorpe

      Hi. You didn’t give ranges for the frees, so it’s hard to comment. But if the free T3 is in the upper section of the range and that free T4 is below range, it usually means the T4 is converting like mad to give you the free T3 you are getting.

      • Doaa

        Hi again (and sorry for my late reply because I was away from home), the ranges for the frees are as follows: FT3: 2.00-4.40; FT4 is: 0.93-1.79

  5. Cynde Liffick

    My latest labs show my Free t3 to be high (I was working on lowering RT3 so I was taking 55 mcg of T3 a day) and elevated alkaline phosphotase which my doctor said is primarily due to bone. His thought then is that the high T3 is causing it.
    My progesterone,estrogen and testosterone are also low as is VIt B12.
    Are there any sources that directly discuss high T3 as opposed to low TSH?

  6. Elaine Will

    Well the dr called me and told me he could not give me more meds due to the tsh being .8. He said it would throw my heart into Afib. So there we have it. My huge hopes changing to ndt have been dashed and I am left worse off then on synthroid. At least on synthroid I had a high ft4. Changing to a new dr will take months of waiting for an appointment, thus living like this. I am going to make some calls today but I dont have a lot of hope. He had told me in the beginning that he treats the person rather than the labs so I had faith. He had also told me he would not leave me feeling poorly when I asked him a lot of what ifs.
    So he said to give it 4 more weeks to see if anything changes. Do you honestly think anything will change or raise in that amount of time? I need to get through Christmas. I have 7 children who are depending on mom to be a happy person. This depression is the worst symptom of all. In the meantime I am doing all the reading I can to see what I can naturally do to raise the t3 and t4 levels.
    When i asked him about the ft4 being below normal, he said I wasnt getting any t4. I dont know why he said that. Sooo sad today.

    • Janie Bowthorpe

      My TSH on my optimal dose of NDT has always been .008 or .004 and I’ve never had afib. Same with others who are optimal. Google Thyrogold. It works.

  7. Elaine Will

    Thank you!! I am praying about my drs phone call today so that he will raise my dose. My dose raising has been rough for me. Feel poorly, then feel a huge sense of well being and health, then crummy again. Hoping we will get things right.
    Another question. I got my selenium tested and the number is 230. It appears to be in the upper range as 330 is the high. Whenever I take selenium 200s or 150s, I seem to get high anxiety by the evening. I cannot find any info on this. Any thoughts?

  8. Elaine Will

    I switched to naturethroid 4 mo ago. I went hypo quickly and have been climbing out by increasing the dose gradually. Too gradually but at least someone is helping by prescribing it. My recent labs show tsh .8 (.3 t0 4.4) , ft3 2.44 ( 2.0 to 4.4), and ft4 .8 (.93 to 1.7).
    What should I ask the dr? I am afraid he will not raise the dose. Do you think I am hypo still? I am fighting depression terribly and my menstrual cycles are now irregular and just spotting and light instead of healthy. I dont want to throw myself into menopause by taking this drug. Is there anything to that? I have never been irregular even when hypo before. I guess I am anxious that I will never feel good again. On synthroid I went through spurts of feeling great and feeling crummy . My numbers when on synthroid had my ft4 going above range often. Natural dr told me I was on too much synthroid and should switch to nature throid.
    Thank you for your website!!!

  9. Keressa

    Thank you for your reply and link. I’m wondering why the tsh would go down if my medication was reduced. My current tsh is .0013. Isn’t that extraordinarily low? I was tested for the hashimoto’s antibodies 9 yrs ago, I was positive. On another note I would like to try low dose naltroxene to help with the hashimoto’s. Any experience with that? Thank you!

    • Janie Bowthorpe

      Hi there. I explained why in my other reply. i.e. if you do have Hashi’s, lowering your thyroid meds based on the lousy TSH makes us more hypothyroid, which in turn can cause the antibodies go up, which in turn can cause thyroid cells to be attacked and to slough off, making the TSH fall due to “hyper” from the die off. If you suspect hypopituitary, patients will do other tests to see what’s going on there: https://stopthethyroidmadness.com/hypopituitary But it doesn’t change that we’ve learned repeatedly not to let a doctor dose us by the TSH, but by the free T3 and Free T4 and more.

  10. Keressa Page

    I have had Hashimoto’s for 9 years. I was on 150 mg Synthroid and 2 doses of 5 mpg Cytomel for almost all those years. In Dec 2015 my blood work came back with normal FT3 3.0 & FT4 1.05 but TSH .02. Doctor lowered my medication to 150mg synthroid and 1 doses of 5 mpg Cytomel. Blood was retested and FT3 went up a bit but still normal 3.6 and FT4 went up a bit 1.33 but TSH dropped to .016. Then medication got reduced to 137 mg Synthroid and 1 dose of 5 mcg Cytomel. I was retested 6 weeks later and TSH is now .0013. Doctor wants to change me to 117 mg Synthroid and 5 mpg of Cytomel. Yesterday I had a HORRIBLE day where I cried all day, exhausted, cannot work or do anything. I am very swollen, moonfaced and gained 5 lbs in one day. Why is my TSH dropping with less Thyroid medication? Could I now have Graves and Hashimoto’s? Could I have a problem with my pituitary gland instead of thyroid? I am gluten free, take all the supplements, eat low fat and exercise for hours everyday. I cannot lose weight, just gain it

    • Janie Bowthorpe

      Keressa, we have noticed repeatedly that it is normal for a TSH to go quite low when having T3 in one’s treatment, like your former .02. And sadly, when doctors go by that low TSH, and thus lower our medications, we get worse. See this information: https://stopthethyroidmadness.com/tsh-why-its-useless I don’t know if you have Hashi’s without you testing for both antibodies (and a small body of folks have Hashi’s without antibodies, but it’s rare), but antibodies go up due to being poorly treated, causing more die-off of your thyroid, and thus the lowered TSH.

  11. Debra Nagle

    I just had my blood work done and I am confused on one number. My FT4 is 1.30 and my T3 is 4.0. However, my TSH is <0.03 which is out of range. I was taking 2 1/2 grains at the time of having my blood test and now I am taking 2 grains and getting ready to go to 1 3/4. What does my number of TSH mean and how do I get that to the right range? I am confused. Thank you.

  12. Maria

    Right thyroid removed I am on ndt 60 mg per day 2 doses of 30 mg per day my ths is low my t4 is low and my t3 is in upper range and my teeth hurts why will it effect my bone density please help

    Thanks Janie

  13. Nikolas Britton

    Suppressed thyroid STIMULATING hormone, TSH, is simply a natural response to having adequate thyroid hormone levels. It’s a negative feed back loop, and I don’t understand why doctors don’t get this. It parallels that of a thermostat calling for a furnace to turn on. With the exception of individuals that have actual thyroid defects or other disease states, the body auto-regulates everything and will not switch to hyperthyroidism.

    You want low TSH, and if you have high TSH, the first thing to check is iodine intake. Without iodine, the thyroid can’t produce thyroid hormones. The thyroid is a very simple organ, but doctors apparently have a hard time wrapping their heads around this concept of a negative feedback loop. Endocrinologists understand negative feedback loops, but the wealth of bad research has led them into mismanaging thyroid disorders. Low TSH with normal T4 and T3 is the goal, this indicates everything is working perfectly. If you have high TSH with low T4, addressing possible iodine deficiency is the first step. When TSH is low the body readily eliminates excess iodine, and goiter is only a problem in those with a selenium deficiency, or actual thyroid defects. If iodine is not the problem then you need to systematically work through the Hypothalamic—pituitary—thyroid axis and it’s negative feedback loop, checking for proper hypothalamus and pituitary function is important. Again, in those with no actual defects in the thyroid, hypothalamus, or pituitary, you actually want low TSH levels, the body auto-regulates thyroid hormone production by suppressing TSH levels once T4 reaches normal levels; TSH works like a thermostat. The belief that someone will switch to hyperthyroidism is bad research, once the root cause has been addressed (i.g. iodine intake), only those with organ defects have this problem. Furthermore, goiter from excessive iodine intake is also bad research, this is really only a problem in those with deficient selenium intake or in those with actual disease states. Most of the time, hypothyroidism is simply due to deficient iodine intake or drug interactions.

    • Ele Larson

      Boy I have to thank you for such a great way of explaining all of this!! I’ve had a doctor a lot of years that was way ahead in prescribing armour. When my TSH. Hit .001 (I’m a Chronic Fatigue Patient) years ago, he didn’t like it, advised I just ‘May’ get Osteoporosis, yada yada. Well I took my vitamins, all my free floating were always normal?

      Well problem is you also have the HMO drs and their nonsense. The Obgyn, and endocrinologist. Because sure enuf, post-menopause there was the Osteoporosis!! And big time! So this A hole endo started to reduce the armour first time in a lifetime? Never wanted to strangle someone so badly!!!

      My ‘witch dr’ who thinks outside the box will be my next visit with YOUR explanation. There are dozens of reasons for the Osteo, primarily the genetics. This moron lady when I told her I could barely move (fibro/chronic fatigue) said ‘well…get your blood tests done and if it’s STILL low we’ll adjust it down again’!!
      I’m 190#!!! Is she insane???

      So empiricism is alive and well – those ‘check lists’ are all they know. TSH means nothing if one’s hormones are fine. Thank you. Sooo right!!

    • Suzanne

      You seem very educated on this subject is I wonder if you can clarify something for me. I have Graves’ disease and have been on t4 only for many years but about a year ago saw endo who said t3 was low so added in 20mcg of t3 to my 100mcg of t4 – feel so much better and have finally managed to lose a few pounds and don’t ache all over every morning. Was called into doctors cos tsh is suppressed, ft4 normal, lab did not do the ft3 (expensive apparently) – the level of tsh was less than 0.01 I think – is this too low. She was going to decrease my t4 but when I said tsh is not a good measure she said if I feel fine to leave it and re-test in 6mths and definitely include ft3. On this site there is mention of lower level of 0.04 being ok – so is mine too low?

  14. Melissa

    I am having Cushings symptoms. Swollen “Moon” face, as well as water retention in my abdomen. My TSH is .06 and my T4 is slightly high, I have no free T3 test, but I have T3 uptake is 35. I am desperate for help. My dr. has reduced my Levothyroxine to 50 mcg. I was taking 100 when the blood was drawn for the results I have given. I have severe depression/anxiety and I can’t take this anymore! PLEASE HELP. I can’t afford an endo dr. I think I have high levels of cortisol. I look like a Cushings patient but 9 wks. ago I took for 2wks Dexomethasone. Since then the cushings symptoms won’t go away. Please help. I am afraid the reduction of my T4 hormone will make me gain more weight. I have gained 25 lbs when on the steroids and it is still here. I had chest pains that have stopped now. probably from the anxiety or edema. It was severe. I looked five months pregnant. Can anyone help me??? Thank you so much!

    (From Janie: Join patients groups. They can definitely help: https://stopthethyroidmadness.com/talk-to-others )

  15. Jolie

    I find it’s best not to listen to British thyroid ‘experts’. They seemingly don’t have the first idea what they are talkng about!

    • Tekin Bora

      I’m hundred percent agree with you British thyroid specialist very ignorant !! I was diagnosed Graves’ disease 2008 and didn’t know anything about disease and poorly treated they gave me same dose Antithyroid medication almost 9 years 300 mg propthyuracil (PTU) unbelieveable..

      • Tekin Bora

        I’m confused some website and country normal thyroid levels freet3 hormone level (3-8 pmol/L normal range) freet4 hormone levels normal range (4-11pmol/L ) this is make me paranoid because uk NHS system normal thyroid levels free t3 (3.1-6.8) normal range this is make me crazy and NHS United Kingdom normal thyroid levels for freet4 (9-19 normal range ) if I follow first thyroid levels sometimes I got normal thyroid levels can you imagine normal thyroid levels and they gave you high dose Antithyroid medication and you are overmedicated and doctor think you have Graves’ disease or still thyrotoxicosis this is crazy…..

  16. Dr. Swerdloff

    USC did a study that found that the upper limit of TSH was way off and published it in the Journal of Endocrinology 2003 where they found that a TSH of >= to 2.4(not 4.5-5 as was previously thought) was already associated with thyroid disease of some sort either nodules or Hashimoto’s disease. So I would venture to hypothesize that the lower limit of the range is also incorrect by at least the same amount. It would be nice to see some research in that direction as well. Remember Dr. Thiery Hertoghe’s great grandfather Dr. Eugene Hertoghe described hypothyroidism as a set of clinical signs and symptoms( including the “Hertoghe Sign of Low Thyroid the loss of the lateral 1/3 of the eyebrow”) (not as a lab condition) that improved with administration of thyroid. It wasn’t till many years later that labs determined that there were four thyroid hormones and that T4 was the most prevalent. The makers of Synthroid equated the most prevalent to most important, little did they know that T4 is similar to pro-insulin in its low activity and that if an individual doesn’t have enough of the Thyroid Peroxidase Enzyme because of Hashimoto’s disease they will not easily be able to cleave off the iodide and make active T3 which is more easily assimilated by the brain and the rest of the body and will ultimately exhibit symptoms of low thyroid.

  17. Theresa

    I plan to print everything on this page to take to my doctor next visit. The replacement doctor I saw last time had never seen such a low TSH test result (0.04). I had a bone mineral density test last year, just before I turned 50, and the result was that my bones are 20 (thanks to desiccated thyroid and it’s contained calcitonin)! I use milk products semi-regularly, and rarely supplement with calcium, so we know where the credit lies! The doctor ordered the test due to very low, out of normal range TSH (consistently in the range of 0.03 – 0.04), which always seems to freak him out. Sadly, I’m still cold, fat, and not very energetic, but I’m awaiting the results of a 4-point cortisol saliva test to determine my adrenal status. If the stress of living 20 years with hypothyroidism alone didn’t stress my adrenals, then raising 3 teenagers and dealing with my husband’s traumatic brain injury from a long fall onto a concrete floor 9 years ago certainly contributed. (He’s fine, even more a workaholic than ever before!)

  18. Eva M. O'Keefe

    You have NO IDEA how much your website has helped me.
    I was literally dying on T4 only and having every symptom of adrenal fatigue. I switched to Naturethroid (which is what I had to begin with before the shortage) and I am taking isocort.. I am a human being again..
    Thank you so much for your valuable research..
    I am buying the book shortly…
    Thank you,

  19. Kara S


    Here’s a comment with medical abstract urls that I’d written recently about suppressed TSH – which is how I function best. Luckily, I found a doc who supports me (and just to be sure, I’d printed out these abstracts and taken them to our first meeting).

    Hope it helps someone – enjoy!


    When I looked into what endos/etc actually said about the negative effects of a suppressed TSH, the only one I see mentioned is OSTEOPOROSIS. That’s it, unless I’m missing something. (And if I am, please do correct me.)
    However, many medical research papers detail groups of patients who were purposely medicated to suppress TSH due to thyroid cancer; The papers show that these patients exhibit NO OSTEOPOROSIS, as long as they have not exhibited physical hyperthyroid symptoms (arrythmia, tremors, etc). These patients were cancer patients, since TSH suppression is the common treatment for that; however, the same findings can be extended to non-cancer patients.
    Other papers point out that the TSH test was developed from a bell curve of “normal” patients, and that any scientist will recognize that bell curves have legitimate outliers (people – like myself and many on these forums – whose perfectly good numbers happen to fit on the tails of the bell curve). In other words, as you already know, high and low TSH’s can be perfectly normal for some people.
    I had printed out these abstracts and other websites in order to take them to my doc so he would hopefully feel comfortable dosing Armour to my symptoms instead of my TSH. (And yes, he is currently doing so, and we are keeping an eye on my bone density, just to be sure.) With luck, they will be useful for others as well.
    T4 Suppression / Osteoporosis – Randomized trial of pamidronate in patients with t… [J Clin Endocrinol Metab. 1998] – PubMed result
    Lack of deleterious effect on bone mineral density… [Endocr Relat Cancer. 2005] – PubMed result
    Treatment of benign nodular goitre with mildly sup… [J Intern Med. 2002] – PubMed result
    Clinical value of a sensitive immunoradiometric as… [Ann Clin Biochem. 1985] – PubMed result
    California Center for Pituitary Disorders at UCSF – Pituitary 101 – Pituitary Disorders – Hypothyroidism
    TSH and Patients’ Experiences: Suppressed to 0.5 / Alt.Support.Thyroid Newsgroup Website
    MyThyroid.com: Osteoporosis


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