Blood results - should I still switch to Erfa? - Thyroid UK

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Blood results - should I still switch to Erfa?

I was diagnosed with an underactive thyroid in 2008 and been on levothyroxine ever since (200mg x 2 days a week, 100 the rest). I had some thyroidy-symptoms (inc hair loss, aching joints and fatigue) so saw an endo privately who prescribed Ertha, which i started two days ago. In the meantime, before starting on new regime got bloods done with medichecks and they were:


FREE THYROXINE 18.58 pmol/L 12.00 - 22.00

TOTAL THYROXINE(T4) 90.9 nmol/L 59.00 - 154.00

FREE T3 4.02 pmol/L 3.10 - 6.80

THYROGLOBULIN ANTIBODY *216.400 IU/mL 0.00 - 115.00


VITAMIN B12 385 pmol/L 140.00 - 724.00

FOLATE (SERUM) 14.92 ug/L 3.89 - 26.80

25 OH VITAMIN D *19.39 nmol/L 50.00 - 200.00

Inflammation marker: CRP high sensitivity, 0.9 mg/l (0.00-5.00)

ferritin - 190.1 ug/l (13-150)

I've been on ferrous sulphate for a year as my ferritin has been low - when last tested in Nov, was still only 57 and with thinning hair, told to keep on it. Should I stop now as seem to be over-medicated?

Also, am literally two days into stopping levothyroxine and starting Erfa - but if my T3 is okay on levothyroixine and its more mineral deficiencies to blame for symptoms, am I dabbling where I needn't? (and having to pay for private prescription). Any advice would be amazing - I'm trying to work through the process as read about on here, but impatient to be feeling better after years (in retrospect) of feeling mildly rubbish. I have a toddler about to turn 2 and it was after his birth, that things started to feel more awry (also have older two boys, originally diagnosed after birth of second).

Thank you so much for all your help to date!

10 Replies


TSH is low, FT4 is high in range and FT4 low in range which indicates you are converting poorly. T3 in Erfa should help raise FT3. Most people on NDT will feel well with FT3 5.0 - 6.80.

Thyroglobulin antibodies are positive for autoimmune thyroid disease (Hashimoto's). There is no cure for Hashimoto's which causes 90% of hypothyroidism. Treatment is for the low thyroid levels it causes. Many people have found that 100% gluten-free diet is helpful in reducing Hashi flares, symptoms and eventually antibodies.

Aching joints are probably due to vitamin D deficiency. Vitamin D is optimal around 100. My GP prescribed 40,000iu D3 daily x 14 followed by 2,000iu daily x 8 weeks to raise vitD from <10 to 107. Vitamin D3 is available without prescription online. Softgel capsules are preferable to tablets as the fat in oil aids absorption. VitD should be taken 4 hours away from Levothyroxine or Erfa.

Ferritin can be elevated due to supplementation or due to infection or inflammation in the body. I would stop supplementing and retest in 4 months. If ferritin is low you may need to resume supplementing.


Thank you! Just having a wobble about switching medication and having to pay for something I might not need, so you've reassured me that I'm on the right track. Am I likely to buy the right kind of Vit D3 in my local healthfood shop?



I've no idea. I buy supplements from Amazon. If you use Amazon please use TUK's affiliate link

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Before switching to Erfa you could try a higher dose of Levothyroxine which would raise FT4 and FT3. If symptoms don't improve you could try Erfa later.


Hi Annie8ell You probably won't get the best kind of D3 in a local health food shop - tip: don't buy any own brands from H&B, Boots or supermarket, they use cheap ingredients, usually the wrong form and plenty of fillers. Best supplements will be found on the internet.

A good D3 will be a softgel with only two ingredients - D3 and olive oil. Here's a good one, at a good price, and the seller is excellent

I followed the loading dose regime Clutter has mentioned, then took 5000iu daily and got my level up, using those softgels, from 15 to 190 in about 2.5 months then went onto a maintenance dose.

When taking D3 there are important co-factors needed

D3 aids absorption of calcium from food and K2-MK7 directs it to bones and teeth rather than arteries and soft tissues.

K2-MK7 -

D3 and K2 are fat soluble so should be taken with the fattiest meal of the day.

Magnesium comes in different forms, check here to see which would suit you best and as it's calming it's best taken in the evening

You can maintain a good ferritin level by eating liver every couple of weeks rather than taking a maintenance dose of iron supplements.


How do you FEEL thats more important than numbers.


DON'T do a direct swap it rarely works. Introduce Erfa slowly.


The endo has prescribed 45mg of Ertha am and pm, gradually building up to 60mg morning and night (after 8 weeks). But he has told me to stop taking levithroxine. Do you think I should keep taking a smaller dose of Levo for a few weeks?


Levo is a storage hormone and can last up to 7 weeks in your system so you can safely drop your levo altogether. Personally I stopped levo for 2 weeks before starting NDT.


Glynisrose ,

This makes little to no sense.

If we assume someone has 100% of their expected full T4 level at the start (Week 0), then the level drops by half every week (a big assumption), then at the end of Week 7, the person would have a mere 0.78% of the T4 they started out with.

That is, they would have so little that it might be below the detection limit of the analyser used. It isn't that T4 lasts for seven weeks, it is that an analyser might just still be able to detect it as a trace.

Week 0 100.00%

Week 1 50.00%

Week 2 25.00%

Week 3 12.50%

Week 4 6.25%

Week 5 3.13%

Week 6 1.56%

Week 7 0.78%

I don't know what is "safe" about allowing thyroid hormone levels to drop so far. Some people, probably the majority, would be suffering severely long before that.


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