Thyroid UK

on thyroxine for hypothyroidism

I was diagnosed with hypothyroidism 2 weeks ago and am on 25mcg thyroxine and i have not noticed a difference yet, how long will it be before i notice a difference?. I am having a blood test in 6 weeks to see if i am on the right dosage, I had a subtotal thyroidectomy in 1990 for hyperthyroidism and was not on any medication since the operation until 2 weeks ago.

9 Replies


Some people seem to notice the effects of taking the tiniest dose within minutes; others hardly notice anything in weeks.

Do you know what your blood test results were 2 weeks ago? (Please post them if you can.) Did you have the blood tests due to symptoms or just as a regular check?

Do you happen to know if your hyperthyroidism (in the past) or hypothyrodism (now) is caused by autoimmune issues?

Tell us a bit more and we might (collectively) be able to help.



thank you for you reply rod, my recent blood test results are these...

Serum TSH level 3.32

Serum Follicle Stimulating Hormone level (iu/L) 4.2

Serum LH level (iuL) 3.7

my TS4 was not tested for some unknown reason and so i had a another blood test for that one 2 weeks ago and it came back at 12.3 from what i can remember.

I have had a blood test every six months since having my thryoidectomy but about 2 years ago syptoms of hypo came on and i was back and forth to the doctor getting borderline results then being told it was my hormones (I am 48) I was put on statins because my cholesterol level went up to 7 which i believe was caused by hypo, I was really ill on them and stopped taking them and now eventually have been put on thyroxine. My hyperthyroidism is genetic it runs in my family and i believe was brought on by the shock of my fathers sudden death when i was 12 but i was not diagnosed until i was in my early 20s and had my first child. Do you think i might need a higher dose?


There are far too many cases where statins have been prescribed to people who are hypo - and they have suffered to varying degrees. (Seems that some statins are worse than others, but that doesn't amount to an endorsement of any of them as I see it.)

Surely it makes sense to get thyroid hormones (and as you obviously know, low thyroid hormones are definitive causes of raised cholesterol) up to sensible values and see what impact they have on cholesterol before considering statins?

I'd suspect that 25mcg isn't going to be enough - but it might be difficult to get an increase until you have gone through the 6 weeks the doctor is expecting.

I'd recommend that you record the results of every test you have - including the reference range - if possible. Time will come you will be glad you did.



thank you Rod i will take your advice and record my results, i am also experiencing a lot of joint pain and read that this can be caused by hypo do you know if that is the case?


I can confirm from personal experience that joint pain most definitely can be a symptom of thyroid troubles! It's another symptom that many doctors are unaware of, and often suggest that the patient probably has arthritis.

If your joint pain is caused by your body not having enough thyroxine, it generally resolves once you have found your optimum dose. The bad news is that finding your optimum dose isn't always as straightforward as we would hope. It's good to be aware that having too much thyroxine can cause many of the same symptoms as having too little.


Hi Annamarie,

Some people find improvement within a day or two but thyroxine has a half life of 7-10 days and so some people do not notice anything for a couple of weeks. Also, some people need to be on 50mcg before they notice improvement.

It looks like your doc is treating you before you come outside of the TSH range - which is unusual. Be aware that he may not want to increase your dosage if you don't have any improvement.

Keep a diary of test results, ranges and symptoms on a 1-10 scale. Redo the symptoms list every two weeks and you can then see whether you are improving or not. Docs like evidence like this too.

Tell your doc that some endocrinologists feel patients don't feel better until their TSH is right at the bottom of the range.


thank you for your reply lynmynott, i dont know how much thyroid i have left after my subtotal thyroidectomy and i think thats why i am on the lowest dose.


When they took one of my lobes away, they put me on 200mcg and I thought I was going to die!! I took it back to 25mcg and over the next 18 months increased it very slowly. However, I had probably been hypothyroid for years.


when i had my subtotal thyroidectomy in 1990 i was not put on any medication at all and i would say i have been suffering hypo symptoms for years but only over the past 2 years have been back and forth to the doctor with loads of symptoms, am wondering if they had put me on some medication when i had most of it out would i be in this position today? am also suffering a lot of joint pain have read somewhere that this can be caused by hypo?


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