Thyroid UK
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I need some medical references regarding TSH under 1, and the benefits?

I have just had my bloods taken,no results yet. Whilst i was there i spoke to my Dr about the research i had undertaken regarding my thyroid status and that a tsh level of under one seems to be preferable. He seemed to be a bit shocked by this, although he seemed to be very open to new ideas about the treatment of hypothyroid. He suggested that tsh of 3 -3.5 he thought would be good. After reading the questions here i believe that i also need to be under 1 in order to get rid of the symptoms.( Which are all of the usual ones).

Is there any medical references that i can show him about TSH under 1?

He told me that my last tsh result was 4.75 which he thought was a bit high. So i need to get some evidence to show him that my new results (some time this week) are much to high! I have to say that he seems very interested in trying to work this out together.Which i see as a big step in the right direction.

Thanks to you all out there, Paul-b x

13 Replies

The medical profession rely heavily on the TSH result but it sometimes isn't the best indicator. You need to know your T3, which is the active hormone. T4 (levo) converts to T3 and it is this that is used by the body not T4. My GP/PCT won't test for T3. If you feel well on a TSH of around 1, then the T4 is converting well but in many cases it doesn't and people continue to feel unwell . This could be low cortisil/DHEA levels or a vitamin/mineral deficiency such as B12, folate, Vitamin D3, magnesium, ferritin/iron or copper/zinc.

I have no specific information or medical references I can suggest about TSH under 1. If your bloods come back around 1 and you are still feeling unwell, then something is not working for you.

Hope this helps.


Thankyou for your answer, i am doing a saliva test tomorrow for adrenal/cortisil. I then have to wait two weeks for results. So hopefully i can see if i am converting properly. Thanx again jan4363


If you buy the 'understanding Thyroid Disorders' by Dr Toft, they can't argue with it because its by the BMA. It's what they recommend.

Dr Toft states TSH should ideally be under 1 and T4 should be near the top of range, very useful reference and only costs a fiver. It is available at most chemists.


Hi Mitchell , i will go and get it in the am thanks.


It may also state that some need to have a suppressed TSH and/or the addition of T3. I haven't read it but an article he wrote for Pulse online does


I found this , may be of help



Thankyou Roslin, i am reading through it. Trying to understand it.

Much appreciated paul-b


Thyroid stimulating hormone (TSH) is a pituitary hormone - the Thyroid should respond then there's a loop back to say it has. If there's something wrong with the pituitary then this test is pretty useless, if the Thyroid can't produce the theory is TSH will go up as the pituitary will 'keep knocking' 'til it does - 'normal' is under 1, Thyroid cancer patients have treatment which suppress any hormone production.

However it seems labs took random people's existing blood tests for data and created a range (do normal 'well' people get a blood test?). As other such blood tests are 'linear' and mostly reliable, the TSH is presumed to be too (but it isn't!). Actual Thyroid hormones should be measured - Free T4 (free means available) and FT3 (which is the one that actually supplies each cell with energy). Also things may be hanging around in blood serum but not where they are supposed to be!

Well that's my understanding anyway! Here's another post about TSH with links... J :D


Thanx that's great! printed it off and will take to the Drs.

Regards paul-b


Hi, I emailed this to my DR which seemed to help.....feel free to copy and paste/ print. Best wishes....

Following my appointment last week, I have arranged for a blood test for Friday. Although I know that this will be 'within range' ( I am guessing at around 1.2) I have sent you a couple of articles regarding the dosing of Levothyroxine.

In the light of these, I would ask that you perhaps reconsider seeing if I feel any better on a higher dose of Levothyroxine? The articles below recommend a level of 0.2- 0.5.



Dr Tony Toft is consultant physician and endocrinologist at the Royal Infirmary of Edinburgh, and a former president of the Royal College of Physicians of Edinburgh and of the British Thyroid Association

What is the correct dose of thyroxine and is there any rationale for adding in tri-iodothyronine?

The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated - 18- 22pmol/l. Most patients will feel well in that circumstance.

But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal -that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l).

Even while taking the slightly higher dose of levothyroxine a handful of patients continue to complain that a sense of wellbeing has not been restored. A trial of levothyroxine and tri-iodothyronine is not unreasonable.

The dose of levothyroxine should be reduced by 50µg daily and tri iodothyronine in a dose of 10µg (half a tablet) daily added.

While taking both hormones it is important serum TSH is normal and not suppressed.


Latest Update: April 22, 2013


Avoiding the "Tyranny of the Test"

Finding Your Optimal Dose of Thyroid Medicine

By Richard Shames MD, with Karilee Halo Shames PhD, RN, HNC

As a General Practice physician who has been providing thyroid care for over 30 years, I am continually surprised by my patients' stories of their experience with endocrinologists. Many times patients tells me that they had just begun to feel slightly better on thyroid medicine when their specialist said, "This is it. We can not increase any further. Your tests tell me you're presently at just the right dose." Evidently they had started working with this doctor right around the time of the low thyroid diagnosis. They had begun a low dose of maybe 75mcg. of Synthroid, and were beginning to feel better than rock bottom, but not great. Now, some years later, they are still feeling only partially back to their original full self.

They keep telling this to their specialist, who then keeps responding, "we can't increase the dose any further. Your tests are fine now."

When confronted with what may be unfair tyranny of the test, I generally tell my patients they have several options. Any one of their choices might boost them up from their present partial recovery to perhaps 90 or 100% of their prior full function. These options include:

Controlled trial of more thyroxine

Switching brands of thyroxine.

Adding some T-3 (Cytomel) to the thyroxine regime.

Switching to Thyrolar (brand name mix of T-3/ T-4).

Trying animal thyroid (Armour or Nature-throid).

Boosting any medication with natural therapies.

This present discussion will focus only on option #1. (Stay tuned! Our write-up of the other options will appear in later articles on this website.)

First of all, 75 or 100 mcg. of thyroxine are a modest dosage for most adults. A well-known professor of endocrinology is convinced that a good "rule of thumb" eventual dose for most of his patients is one microgram per pound of body weight. For instance, a woman who weighs 137 pounds might do well with 137 mcg. of thyroxine (a few brands other than Synthroid are available in pills at this exact dose). A man who weighs 175 pounds might do well with the 175 mcg. pill. Before acquiescing to your doctor's test-result edict of final dose, you might want to ask for a short clinical trial of the medical center professor's protocol of "one mcg per pound of body weight". Keep in mind that the rule of thumb dosage is only a general initial guide, and that it might not apply well in cases of obesity.

If your doctor says "no, I realize you would like more medicine, but I don't think that is wise considering your test results," then you might want to look at your tests very carefully. Most likely your doctor is talking about the level of TSH (thyroid stimulating hormone). Many physicians are wrongly seeking to have their patients arrive at a TSH level that is in the mid-normal range. In actuality, the mid-normal range is a great target goal for most blood test results. However, it is not generally the most sensible goal of therapy for thyroid patients taking thyroid pills. Instead, for most thyroid sufferers, the goal of therapy should be to achieve a TSH near the low end of the normal range. Let us explain why.

The "normal" range of the TSH test generally runs from 0. 4 - 5.2. When I consult with people who call me from different parts of the country, I suggest to them a therapeutic target range of 0.3 - 0.5. This is at the low end of the test's normal range, not the mid-normal. The reason I do this is that most people who are suffering from low thyroid are ill because of antibodies from the immune system wrongly attacking the thyroid gland, and thereby compromising its function.

This immune attack is often lessened when the thyroid gland is stimulated as little as possible by TSH. Recall that TSH means "thyroid STIMULATING hormone". Rather, the person generally does better when her body runs on thyroid hormone pills, allowing the gland to be in a mostly unstimulated, resting state. The gland thereby receives a well-deserved vacation, in order to heal and repair the immune system damage that caused the illness in the first place.

Sometimes, both patients and doctors are concerned about this maneuver -- called "TSH suppression" -- where the TSH level is suppressed to just at or just below the lower end of the normal range. They evidently feel that giving the thyroid gland a healing vacation will cause harm or result in the gland being irreversibly turned off. After working in this way for a great many years, consulting for with numerous university specialists, and combing the relevant medical literature, I am totally convinced that thyroid glands are not at all injured by this maneuver.

If you haven't yet begun to feel as well as you would like, then you get to look at this TSH issue very carefully. If the dose of thyroxine you are currently taking (Synthroid, Levoxyl, Unithroid, Levothroid, L-thyroxine, Levothyroxine) has not resulted in a TSH that is down to the lower end of the normal range, then you may not be taking enough medicine. Neither I - nor any other doctor - can promise you that simply taking an amount of thyroxine to reach a TSH of 0.3, or 0.4, or 0.5 will give you full and lasting resolution of your thyroid difficulties. But I can tell you this - it is the next thing to try on your journey to full recovery. You may well be getting short-changed due to an under-informed or overly cautious medical provider.

1 like

Hi Cal, that's perfect thankyou very much. Just what I was looking for!

Have printed it off and will take it with me this week, thanks again.



You're welcome x


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