Advice on blood results and reverse T3 - Thyroid UK

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Advice on blood results and reverse T3

Fluffyone profile image

I have Hashimotos and although my TSH suggests I should be good I am still symptomatic so am speaking to GP re. FT3 and possible medication (liothyronine) along with my Levothyroxine 100. 🤞what’s the best thing to say to my Dr as they said fine as within range. Blood results are below.

Seen posts about reverse T3 also, do GPS offer this test or is it only private? Do I need to have this test?

Thank you so much


15 Replies
SlowDragon profile image

For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested.

Also EXTREMELY important to test vitamin D, folate, ferritin and B12

Low vitamin levels are extremely common, especially as you have autoimmune thyroid disease (Hashimoto's) diagnosed by raised Thyroid antibodies

What vitamin supplements are you currently taking?

When were vitamin levels last tested

Ask GP to test vitamin levels

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

currently your Ft3 is low relatively to Ft4

Ft4 is 64% through range

But 24.32% through range

Helpful calculator for working out percentage through range

Poor conversion is common with Hashimoto’s

Improving low vitamin levels can help improve conversion

Are you currently on strictly gluten free diet?

If not, ask GP for coeliac blood test BEFORE trial of gluten free diet

Email Dionne at Thyroid UK for list of recommend thyroid specialist endocrinologists who will prescribe T3

GP can not initiate T3. Only continue prescription started for first 3-6 month trial by endocrinologist

Fluffyone profile image
Fluffyone in reply to SlowDragon

Sorry forgot to say, yes I follow a GF free diet also.

SlowDragon profile image

Noticed your profile mentions statins

High cholesterol is linked to being Hypothyroid and under medicated

If you have an underactive thyroid (hypothyroidism), treatment may be delayed until this problem is treated. This is because having an underactive thyroid can lead to an increased cholesterol level, and treating hypothyroidism may cause your cholesterol level to decrease, without the need for statins. Statins are also more likely to cause muscle damage in people with an underactive thyroid.

guidelines on dose levothyroxine by weight

Even if we don’t start on full replacement dose, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until on full replacement dose

NICE guidelines on full replacement dose


Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Traditionally we have tended to start patients on a low dose of levothyroxine and titrate it up over a period of months.

RCT evidence suggests that for the majority of patients this is not necessary and may waste resources.

For patients aged >60y or with ischaemic heart disease, start levothyroxine at 25–50μg daily and titrate up every 3 to 6 weeks as tolerated.

For ALL other patients start at full replacement dose. For most this will equate to 1.6 μg/kg/day (approximately 100μg for a 60kg woman and 125μg for a 75kg man).

If you are starting treatment for subclinical hypothyroidism, this article advises starting at a dose close to the full treatment dose on the basis that it is difficult to assess symptom response unless a therapeutic dose has been trialled.

A small Dutch double-blind cross-over study (ArchIntMed 2010;170:1996) demonstrated that night time rather than morning dosing improved TSH suppression and free T4 measurements, but made no difference to subjective wellbeing. It is reasonable to take levothyroxine at night rather than in the morning, especially for individuals who do not eat late at night.

BMJ also clear on dose required

Fluffyone profile image
Fluffyone in reply to SlowDragon

Hi, thank you for such a thorough reply. Vitamins tested 27 July this year along with everything else. Had thyroid panel done again as they didn’t do Ft4 or FT3 so asked for them.

My tests were done exactly as you suggested.

TPO antibodies done in 2019 249. Range o.oo- 34.00

Pre diabetic

I take Vitamin D and Vitamin D protocol


Folic acid


Omega 3



What do you think of these?

So vitamin D in July 160.2nmol/L. Range. >50.00 nmol/L

B12 726 ng/L. Range 197-771.

So Dr will need to refer me to endocrinologist?

Is reverse T3 important?


Brain fog

Foot pain

Pins and needles

Joint pain muscle pain

Low mood

Thank you 🙏

SlowDragon profile image
SlowDragonAdministrator in reply to Fluffyone

Are you currently taking any B12 or just folic acid?

recommended on here to supplement a good quality daily vitamin B complex, one with folate in (not folic acid)

This can help keep all B vitamins in balance and will help improve B12 levels too

Difference between folate and folic acid

Many Hashimoto’s patients have MTHFR gene variation and can have trouble processing folic acid.

B vitamins best taken after breakfast

Igennus Super B is good quality and cheap vitamin B complex. Contains folate. Full dose is two tablets per day. Many/most people may only need one tablet per day. Certainly only start on one per day (or even half tablet per day for first couple of weeks)

Or Thorne Basic B or jarrow B-right are other options that contain folate, but both are large capsules

If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before any blood tests, as biotin can falsely affect test results

Vitamin D is rather high. Suggest you reduce dose

How much were you taking - aiming for 125-150nmol

When were iron and ferritin last tested?

Never supplement iron without doing full iron panel test for anaemia first

Eating iron rich foods like liver or liver pate once a week plus other red meat, pumpkin seeds and dark chocolate, plus daily orange juice or other vitamin C rich drink can help improve iron absorption

List of iron rich foods

Links about iron and ferritin

Fluffyone profile image
Fluffyone in reply to SlowDragon

May 2019, weren’t done this time for some reason 🤷🏽‍♀️

SlowDragon profile image
SlowDragonAdministrator in reply to Fluffyone

Foot pain often low Ft3

Pins and needles can be low Ft3/low B vitamins

Joint pain frequently gluten intolerance or low Ft3

How long have you been strictly gluten free

Fluffyone profile image
Fluffyone in reply to SlowDragon

GF for a while, when diagnosed. 2019. Went dairy free and gluten free. Re introduced dairy.

Serum Folate 2.2 ug/L. Range 3.3-19.3 July, so Dr prescribed Folic Acid tablets 5mg.

Not taking any B complex as levels seemed ok.

Vitamin D dose was suggested on Vitamin D group, they also said that higher level good up to 200.

SlowDragon profile image
SlowDragonAdministrator in reply to Fluffyone

We wouldn’t agree with such high vitamin D levels on here ...obviously that’s your choice

With your Vit D, are you also taking it's important cofactors - magnesium and Vit K2-MK7?

Magnesium best taken in the afternoon or evening, but must be four hours away from levothyroxine

Vitamin K2 mk7

If you are not taking any B12 ...high B12 might be misleading. If other B vitamins are low, B12 can’t be utilised

Fluffyone profile image
Fluffyone in reply to SlowDragon

Yes taking all co factors, will reduce dose of D. Ok so carry on taking Folic acid, ferrous sulphate and add in a a B complex? What would best one and dose be?

SlowDragon profile image
SlowDragonAdministrator in reply to Fluffyone

No You don’t need both

folate within vitamin B complex replaces folic acid. Often much easier to use folate compared to Folic acid

Fluffyone profile image
Fluffyone in reply to SlowDragon

Oh my gosh, one of GPS has just been so dismissive and rude to me when I spoke to him about ongoing symptoms and lower end FT3.

He said my symptoms didn’t have anything to do with thyroid. I said you don’t even know what my symptoms are!

Said FT3 was mid range and FT 4 upper. TSH low so what are you expecting me to do?

Asked for private referral.

Didn’t ask for full iron panel or coeliacs test because of say he was so will ask endo hopefully.

Think that’s the worst Ive ever been made to feel by a medical professional. 🙁

SlowDragon profile image
SlowDragonAdministrator in reply to Fluffyone

Roughly where in the UK are you?

Have you got the List of recommended thyroid specialist endocrinologists who will prescribe T3 from Dionne at Thyroid UK yet?

Important to pick the right endo. Vast majority of endocrinologists are diabetes specialists and waste of time and money seeing

Have you started daily vitamin B complex instead of folic acid. Remember to stop taking this a week before ALL blood tests as it contains biotin which can falsely affect some test results

Likely to need the addition of small doses of T3 alongside levothyroxine

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,

"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)."

(That’s Ft3 at 58% minimum through range)

You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor

 please email Dionne at

Fluffyone profile image
Fluffyone in reply to SlowDragon

In South Staffs. Yes I have list thank you. Was going to try to see Dr at Birmingham QE that’s on the list.

SlowDragon profile image
SlowDragonAdministrator in reply to Fluffyone

Recommend getting vitamin levels optimal FIRST

Testing for coeliac too

Assuming negative...then trialing strictly gluten free before considering adding T3

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