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Thyroid UK
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How long does levothyroxine take to have an effect?

I'm new to the world of hypothyroidism.

I was trialed on levothyroxine for a month and although I didn't feel too much of an effect, once they ran out I felt terrible. I had my blood test results back which showed that the thyroxine was needed so I have definitely been put on them.

Do any of you have hypothyroidism completely under control? Or feel "normal" on their medication. All the stories, threads etc that I've read seem like horror stories.

My case isn't too bad at the moment compared to some if what I've read, but as my body is building up antibodies to my thyroid I have a feeling its only going to get worse.

The main things that bother me is the tiredness (which is the one thing I've noticed a slight improvement on) and being constantly cold. After that, it's the dry, thinning hair and excessive hair loss and the dry skin.

I'm to go back for more bloods in 6-8 weeks to check the levothyroxine dose

3 Replies


Personally I think it's a difficult one to answer (although I'm sure someone with far more knowledge will post a more concrete answer and that there must be a period of time where the meds are securely in your system.)

You also need to look at each symptom and assess any changes made i.e. tiredness - so have you had any or less stress since starting the dose that has an effect?, have you had more/less sleep? have you been more/less energetic for whatever reason? have there been any upsets you've had to deal with? how have you slept generally? ( I can't sleep because I'm so cold and dread waking up once down). What about your diet? have there been any changes there? Has your work or social life affected you positively or neg, this can also link to sleep/tiredness and energy levels. Does the weather affect you? i.e. more sun, have you been outdoors much more/less since starting the dose? All these and much more can have an impact that the medication is working either with or against.

Can you have a period of time in your life to measure in a valid way? 'like for like' possibly not, definitely not in my life! lol So extremely difficult; And a boring answer I know, but there's no point asking for more meds (speaking generally) if you have far too much stress in your life that is actually preventing you to sleep! hence 'tiredness' 'cold' etc....

I thought the house was cold when in fact hubby was going mad for me pitting up the heating - it was my Hypo T!!

Analise each symptom - it's very difficult to give a definite answer I would say although I'm sure there is a period of time where the meds should be securely in your system.

However, when 1st diagnosed 2.5 years ago I was told it would take at least 3 months to have any affect, perhaps 6 months to 'level out'.

The nurse only last month raised my meds and said I would feel a difference in 2 weeks!! and to get back for full blood tests. DON'T get caught up with the 'placebo' trial. I was SO relieved they agreed to raise my medication (2 years of battling and threatening with a private consultant) I could have easily said 'yes I feel much better' within just 2 weeks - but when I look at my 'core symptoms' and analyse, there's actually not much difference - so be aware!! This is how the GP's play it.

Rambled on a bit... sorry!


I don't mind the rambling, I'm a rambler myself lol

Things are pretty much the same in my life apart from moving house back in January but things are settling down now. I have two young kids (4 & 2) so for a long time put the tiredness down to that, but once the youngest started sleeping through I started to think the tiredness was not normal. I've always been sensitive to the cold but its not until my partner and parents coming to my house( I'm a childminder) started commenting in how hot the house was, that I realised there was a problem there too.

Then there's the things that I suffered with that I didn't realise we're connected until I looked into it further which made me book the appointment to get my thyroid checked.

My dad has under active thyroid too. I first had tests 7 years ago and was borderline but the doctors at that surgery were rubbish. My new surgery are much better, it's them that diagnosed me and they genuinely seemed interested in my problems and keen to get to the bottom of it.

Even though its lifelong medication I feel a weight has been lifted just knowing that there is actually something wrong with my and I'm not just being a hypochondriac.

The fatigue has lifted a bit, I can tell just by how many jobs I'm getting done around the house compared to before but so far that's the only difference I've noticed, but I am only in the first couple of months of treatment so I'm hoping things do pick up. With it being hormones I had a feeling they would have a quick effect and then level out. The doctor reviewing my bloods didn't ask about how I was feeling he went purely on the results but I think that's because he had noticed a positive difference in the results before I even went into the room. Suppose if there wasn't much change, he might of tried to catch me out with the placebo


Sounds like you know what's what. Good for you, and you seem to have a good surgery unlike most here, me especially. Poor children lol! they must have been frazzled in your house, I even got a hating engineer to take a look at mine it cost me £210 to be told nothing much was wrong - I didn't click even then! lol!.

PR x


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