How is my conversion?: Hello again, everyone... - Thyroid UK

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How is my conversion?


Hello again, everyone :) hope you've all been well.

After a few bungled NHS blood tests, I've finally managed to get ahold of some full, up-to-date thyroid results. This is where I'm at currently, having been on 150mcg Levo since late July. (Lab ranges in brackets.)

TSH: 10 (0.27-4.2)

T3: 2.8 (3.1-6.8)

T4: 15.4 (12.0-22.0)

Not looking amazing, but I'm not losing hope just yet since I'm due for an endo appointment in the next 1-2 weeks. Just wondering what these results say about my conversion so I kind of know what to expect when I go to my next appointment x

20 Replies


Just wondering what these results say about my conversion

Nothing yet I'm afraid. TSH need to be down to around 1 (or lower) with FT4 as high as possible, then you see where your FT3 lies to know how well you convert.

Optimal nutrient levels play an important part too, so you need to test

Vit D




lau99 in reply to SeasideSusie

Oh, I see...guess I have a bit longer to wait before we can even begin to determine anything :( Thank you for your input though, SeasideSusie x


Do you always get same brand of levothyroxine?

Are you remembering to take levothyroxine everyday

(Weekly pill dispenser can be very helpful)

BEFORE seeing any thyroid specialist endocrinologist would strongly recommend getting FULL Thyroid and vitamin testing

Or insist that GP test vitamin D, folate, ferritin and B12

For full Thyroid evaluation you need TSH, FT4 and FT3 tested. EXTREMELY important to test vitamin D, folate, ferritin and B12

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

Is this how you do your tests?

Private tests are available as NHS currently rarely tests Ft3 or thyroid antibodies or all relevant vitamins

List of private testing options

Medichecks Thyroid plus vitamins including folate (private blood draw required)

Thriva Thyroid plus antibodies and vitamins By DIY fingerpick test

Thriva also offer just vitamin testing

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins by DIY fingerprick test

If you can get GP to test vitamins and antibodies then cheapest option for just TSH, FT4 and FT3

£29 (via NHS private service ) and 10% off if go on thyroid uk for code

Do you have lactose intolerance?

Or suspect you have lactose intolerance?

TSH is remarkably variable and now high again on quite large dose levothyroxine

This looks to be a strong case for inadequate conversion. Your FT4/FT3 ratio which indicates efficiency of conversion is nearly 6/1. And with TSH = 10, the failure of current treatment is obvious. How do you feel on your T4 dosage? If not well, then a T3 addition seems to be the best way to go to get your FT3 well into the reference range. If TSH levels drop very greatly say down to less than 1 this should be no concern if FT4/FT3 levels are well within range- preferably the upper half. NOTE WELL: it is no use upping your T4 dose more on its own. I forecast the FT3 won't rise a lot whereas your FT4 will go to the top of the range or above.

lau99 in reply to diogenes

I was absolutely gutted when my endo asked to titrate my dose down from 200mcg to 150mcg, because although I could understand the rationale, I just knew I'd feel awful on it. I was right! Low mood, terrible bloating + digestive issues, weight gain...all what I was worried about from when I was last on 150mcg. Hopefully this might persuade my endo to take some more drastic measures with my treatment?

Hey there again :

It is apparent from this last set of results that your T3 has now fallen through the bottom of the range,

You have followed instructions and taken various higher levels of T4 - Levothyroxine - but surely when your endo sees these results it will be suggested that you are to prescribed a trial of T3 to take alongside your T4 in order to balance out your thyroid hormones.

No thyroid hormone replacement works well if ferritin, folate, B12 and vitamin D are not maintained at optimal levels so these most probably need working on as they may well be in the NHS ranges but not necessarily high enough to assist the medication working.

I can only keep repeating what I've said before and know I sound like a broken record.

You are not well and struggling in so many ways - hopefully this new endocrinologist knows their stuff and you must be dosed and monitored on T3 and T4 blood test results with a view that both these vital hormones need to be in the upper quadrant of the ranges and at a level high enough to support you with a level of wellness that you find acceptable.

Take good care, guessing you're in isolation at University in Exeter.

P. S. :

In answer to the question - your conversion isn't good - just divide your T3 into your T4 : most people feel well when this is between 1/3.50 - 4.50 - T3 to T4 with most people preferring to be at around 4 or under :

However I have to say when I was declined a trial of T3 because of my suppressed TSH my conversion was coming in at 1/5.25 and the endo didn't think it was anything to be concerned about, so fingers crossed - however with a TSH at 10 they must do something for you, and it is not more T4- Levothyroxine, as they have already used that strategy and it has not worked.

P.P.S, ;

Just to say T3 is about 4 times more powerful than T4 and it will kick start your metabolism and bring your TSH down to where it needs it be, at around 1, or lower, and this is perfectly ok, and nothing to be concerned about.

You have lost your own thyroid due to surgery for Graves Disease and have therefore lost your own natural thyroid production and a fully functioning working thyroid would be supporting you on a daily basis with trace elements of T1. T2. and calcitonin plus a measure of T3 at around 10 mcg daily plus a measure of T4 at around 100 mcg daily :

lau99 in reply to pennyannie

Thank you, Penny. You're right! I am currently in isolation or "soft lockdown" at the uni. I believe that should be lifted on Monday, though. I really hope and pray that I get the T3 and it helps me, if it doesn't I really don't know what I'll do.

pennyannie in reply to lau99

Hey there

Lets just go one step at a time :

All this strategy has proved is that you will not recover your wellness on T4 only and the next step should be to introduce some T3 - the active hormone that will kick start your metabolism and help with the relief of the symptoms being suffered.

Take good care, keep us in the loop ;

lau99 in reply to pennyannie

Thank you, Penny. I just got a text from my GP saying that my new endo has requested that I go back up to 175mcg (though I can't see that helping much). No mention of T3 just yet. Hopefully it's just to hold me off of being super hypo before our appointment?

pennyannie in reply to lau99

Good morning to you :

Does this endo actually prescribe T3 ?

Which CCG is s/he working under ?

Does your doctor's surgery prescribe T3 at all ?

You can go into :- openprescribing - analyse - and enter your CCG or doctor's surgery and if you then enter Liothyronine ( T3 ) as the drug you can see how supportive your area is compared to others in the country :

It is obvious that you have a conversion issue and the answer is to introduce a little T3 to compensate for the amount your own thyroid gland would have supported you with.

You have been up and down on various levels of T4 prescriptions and been compliant with all their suggestions and nothing has worked well enough for you.

I'm disappointed to say the least.

pennyannie in reply to lau99

Hey there again -

I've just been reading through your post again ;

Please do not take this personally, there is nothing wrong with you or your body.

The fact is that had this happened to you around 20 years ago your doctor, finding you weren't recovering well on just T4, would have prescribed you a little T3 to see if that helped you.

In these past 20 years the price of Liothyronine has risen, just in this country, by some extortionate amount, and rather than review NHS procurement procedures, the NHS CCG decided that they should make this vital thyroid hormone more difficult to prescribe.

Doctors were instructed not to prescribe further prescriptions and encourage patients who were already on T3 to switch back to T4. and any new patient who might benefit from Liothyronine had to be vetted by the local CCG not for medical but financial constraints.

There is the the D IO2 gene thyroid hormone conversion test but have read that even if this proves you have a conversion issue, it does not necessarily guarantee your getting a prescription either :

The fact is your have lost your thyroid to surgery and have lost several thyroid hormones :- trace elements of T1. T2 and calcitonin plus a measure of T3 and T4 and if price restrictions were not paramount both these vital thyroid hormones would be offered to you on the NHS.

Just to add if you wish you can look back into the history of this T3 scandal and think the Thyroid uk website a good start : and you will see that we are still actively lobbying politically as to this current travesty and have all signed a T3 petition which has been talked about in the Houses of Parliament and now has currently been kicked upstairs to the House of Lords :

Your results suggest that your conversion is poor and that you need to be properly medicated!

FT3 is -92% (clearly very low!) through the ref range and FT4 is at 34% ( also low.

Both need to be close to 75% through their respective ranges.

TSH at 10 is too high and signals hypothyroidism and again, the need for better medication!

It would be expected that on 150mcg levo that FT4 would be higher but it clearly isn't and clearly isn't converting to T3 going by that low rate.

Important that you optimise nutrients as others have advised in order to support thyroid function.

Have you had antibodies tested to rule in/ rule out Hashimoto's ?

More levo isn't going to adequately raise FT4 at your rate, and consequently drop TSH, so I suggest that you need to add some T3.

The important thing is to ensure is that FT3 isn't over have a long way to go before that happens!

TSH needs to be close to 1 ( even slightly lower) for good health.

I had a similar experience when my levo was raised from 150 to 175 mcg....felt awful.

My symptoms only began to resolve when I added T3 ( now, far down the line and much trial and error, I'm on T3- only and well)

I tested positive for the Dio2 polymorphism....inherited from both parents so a greater impact on conversion according to research.

Hopefully your endo will prescribe a trial of T3 for a long enough period for it to be effective.....months not weeks! I'm in Scotland and it has been ruled that anyone who has proved to need T3 should have it prescribed by an endo (not a GP).....proving the need can be the hurdle! The rediculous cost nowadays scares them off T3! Good luck with that.

I still buy my own T3 and self medicate, but now under the watchful eye of my new GP who herself has a thyroid problem.

Sorry this is a bit of a rant, hope something here helps!



lau99 in reply to DippyDame

Thank you so much for the in-depth response. Rather than Hashimotos, I actually have Grave's and was treated with a Total Thyroidectomy last April. Since then, I haven't yet been optimally medicated, and these look to be some of my worst results. I am due to see my (relatively) T3 friendly endo hopefully in the next couple of weeks. I pray that T3 really is on the cards for me, and if it is, that it helps because I feel and look terrible being so heavily bloated (among other symptoms) :(

150mcg?? And these results?? This suggests some level of resistance to the Levothyroxine?? And there’s certainly very little conversion going on. I have poor conversion but at least my FT3 stayed at 0% through range when my FT4 was at 16 (9-24) and when I increased Levo and raised it to 23.3 (12-24) it still only raised my FT3 to 3.9 (3.5-6.5) still only 13% through range.

So I really hope that they do introduce T3 because it’s the only thing that helped me 🤗

lau99 in reply to NWA6

It's just insane to me...I'm at a loss for words as well. Even when I was on 200mcg and had a blood test done only a couple of hours after having taken my medicine, my T3 still sat pretty neatly within range. Do you know if there's anything that can be done for Levothyroxine resistance? I'm glad to hear that the T3 helped you, perhaps it can help me too x

NWA6 in reply to lau99

Sorry lau99. I don’t know enough only gleaning knowledge from reading others and their experiences. When you were on 200mcg Levo did it at least register higher in your blood tests? I was on 200mcg to push my FT4 higher and it did 23.3 (12-24) but sadly I said I got minimal return on the conversion still.

I’m currently still on 135mcg Levo per day which keeps my FT4 up around 50ish% through range and then I’m on 25mcg T3 to keep my FT3 high 85-95% through range.

How much do you weigh and what’s your height. 150 mcg is a pretty high dose especially at your age.

Are you taking the meds first thing, empty stomach and not eating anything for an hour after? You could just be not absorbing the thyroxine for some reason.

Also have you tried a different brand of thyroxine.

lau99 in reply to Dk123

Before having my thyroid removed, I was generally around 43-45kg, but since then my weight usually hovers around 47-50kg when I've been on the higher doses of Levo. The heaviest I've been I think is almost 60kg, about a year ago when I was still taking maybe 100mcg or 75mcg. I'm about 160cm tall.

I always make sure to take my thyroxine on an empty stomach and don't eat until at least an hour or so later. I have also tried taking it last thing at night about 3 hours after my last meal per the suggestion of my GP, but I didn't notice much change. I almost always get the Accord levothyroxine, but once before I've had MercuryPharma. No real side-effects or anything with either brand. I'm really not sure why on earth it isn't working properly for me :(

Really strange results then. At your weight I would think 150mcg is too high a dose.

Obviously I’m not a doctor but something is just not quite right with your results and I would demand an Endo referral. Perhaps take your parents/friend with you to the GP appt to demand a referral. GPs will need persuading and 2 is better than 1!

lau99 in reply to Dk123

My doctors seem baffled too. I think this was part of the reason why my old endocrinologist refused to see me anymore a few months back, chalking my poor conversion up to "non-compliance" and using this as a reason to discharge me from his care.

I've since been referred to an endo that seems a bit friendlier and less afraid of T3 medication (as well as more thorough), but even he has only instructed me to go up to 175mcg Levo today, upon seeing these newest results. I am due to see him at an appointment soon, so I'm hoping that he's only asking me to do this for now so that I can manage my symptoms a little better before I next see him to discuss my treatment options.

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