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Thyroid UK
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T4 finally been prescribed - but how much would make a difference?

Hi everyone,

Finally my doctor took my private blood test as evidence that I do have hypothyroidism! So she has prescribed low dose of 25mg because she is nervous to give any more! I have completed one month and she has prescribed another 2 months. I have no symptom changes at all yet.

My question is:- Do you think this dose is likely to have any effect or is it too low? She will organise blood test in 2 months but they will not allow her to have T3 done so I will probably have to get another private test done. I will be able to get TSH and T4 on the NHS.

Blood results:-

from 6 weeks ago are:-

TSH - 4.39 (0.27-4.20)......... High

T4 Total - 100 (64.5-142 nmol/L)

Free T4 - 14.86 (12-22) pmol/L

Free T3 - 4.51 (3.1- 6.8 pmol/L)

Reverse T3 - 23 (10-24 ug/L)

Reverse T3 Ratio - 19.61 (>20) ......... Low

Thank you in advance. I am wondering if taking T3 is actually what I need in addition but I will have to see what the T4 is doing first (I'm aware that we do really need both).

I read an article this morning about how the Natural Thyroid Feedback Loop is affected as soon as any thyroid hormones are taken manually. Wish my doctor would try to understand how taking T4 will affect the TSH because I have a feeling that she will stop my T4 if the TSH gets too low out of range.

Any help appreciated, many thanks to this forum for the support, it's always invaluable.

12 Replies

25mcg is a very low dose, not sufficient to make much of a difference.

50mcg is a starting dose and it does show your GP isn't too knowledgeable about treating someone who has a problem with their thyroid gland.

At least your GP has prescribed due to your symptoms as the BTA says not to prescribe until the TSH is 10.

You dose should be increased by 25mcg T4 around every six weeks/eight weeks until symptoms go and you feel much better I prefer six weekly myself (too low a dose inititally can rebound and make us feel worse). The aim is a TSH of around 1 or lower suits us best.


Hi Shaws, thanks so much for that. I'm so frustrated that she will not increase the dosage this time or probably for at least another 2 months! Ugh!

She is a lovely doctor, just has no knowledge as you say about treating thyroid and scared stiff of giving me too much! In case she puts herself into a sticky situation (so she believes).

She expects me to go in with more written material for her to read each time, and I think she does read it! But makes not a jot of difference if she is tied by the rules of the surgery!


There's some good articles on Thyroiduk.org.uk:




These pages are very useful, thank you shaws




Six weeks is long enough to retest and judge whether 25mcg is sufficient dose. The goal should be to get TSH down to around 1.0, perhaps a little lower. Read Dr. Toft's comments in thyroiduk.org.uk/tuk/about_... Email louise.warvill@thyroiduk.org.uk if you would like a copy of the Pulse article to show your GP.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

1 like

Thank you eljii, I wish I could just double the dose but then I would need to get some more in a months time and Dr may not be so accommodating in future!


Hi Sandy12,

Thank you for replying. I remember your post a month ago to my discussion and I have purchased your e-book from Amazon. (I have read it through once and now need to read it again with pen and paper!) It is all very interesting.

I am not able to get T3 from my GP unfortunately so am investigating buying it privately.

I am so frustrated that we have to do all this research ourselves without the so called 'professionals' to help and guide us! I am just so grateful for this forum as I know everyone else is too. It is truly terrible that so many of us have to suffer to such an extent that our lives are literally 'on hold' for years before finding out ourselves how to help our bodies to get back to where they need to be to feel well again!

The endocrinologist that I saw 2 years was totally hopeless, had no knowledge (although neither did I at that stage!) and now my GP is trying her best to help (which I value very much) but she is so worried about stepping over the red tape line that both she and I are restricted!

Anyway, Sandy I am going to re-read your book again and research this in much more depth along with sending off for some T3 to try.

When you say T3 is needed at very high levels, how would I know how much? By incremental doses and watching for symptoms etc?

Thank you once again


Thank you again Sandy12, I will book another appointment with my GP in 2 weeks which will be 6 weeks after starting the T4 and will talk this through with her.

All incredibly helpful, thanks x


I think 25mg is too low, maybe you should try to see a different doctor who is prepared to do something? She can't compromise your health purely because she is scared to up the dose. The fact that you still have all the symptoms says it all. Never ceases to amaze me how lax doctors can be about this. Joining this site is such an eye opener. Makes you wonder how many people don't join this forum and don't check their bloods with ranges and just trust their doctors, carry on with no quality of life.. Its a serious illness and can cause death.


you are not converting. Why are you hypothyroid? With a high reverse t3 like this, adding t3, will not work. Do you have hashimotos, are you puffy?


Hi faith63,

I am not Hashi, but am puffy significantly along jawline and under chin (watched it progress over 2 years quite suddenly and slightly puffy all over face too.

Knees very puffy to side and above kneecaps.

Hypo only in my mind, because of huge symptom list, inc loss of outer third eyebrows, crimped tongue, patches of hair missing on scalp, hair and skin deteriorating and huge amount of continual pain in legs, lower back and feet (plantar facilitis type pain), weight battle despite cutting carbs to a minimum and exercising regularly. Many other symptoms!

Diagnosed 16 yrs ago withM.E. (Chronic Fatigue) but recent consultant has said it does not correlate to classic symptoms so has said it is not M.E. now.

If I could just get rid of pain in body I would be so elated!


i don't know about ME, but my pituitary is damaged, i have hashimoto's too. i have improperly tested and treated hormones. My thyroid, cortisol are low. I am horribly fatigued and in pain, with swelling in the insides of my feet, belly, eye are..weigh more now than ever, and am not able to eat harly at ll. like walking on bare bone, tight muscles and pain..now diagnosed with chronic fatigue syndrome and fibromyalgia..and the idiot Rheumy., says, that low or missing hormones, will not cause fatigue and pain!! I don't believe it at all. I think its too much of coincidence that i didn't feel ilke this until i got pituitary damage and hashimoto's.. These conditions, are all about improper GH, cortisol and thyroid..A Dr. John Lowe wrote a whole book on it. Replace the nutrients, but the hormones, must be replaced first, and pain will be gone. I believe this is the case for you as well..a dysregulation of hormones.


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