Thyroid UK
84,407 members99,412 posts

When will I notice a difference?

I've been on 50mg of thyroxine for around a week now. I know it can take a few weeks to work properly but should I not be noticing any improvements yet? Am I being impatient? 

I'm still tired and lacking energy and although I'm back on the diet I still seem to be gaining weight. Shouldn't this be better after a week? 

I'm also feeling nauseous, very dizzy and my throat is really hurting. I'm not sure if this is unrelated. I'm also coming off sertraline but doing it very gradually so hoping to not have too many withdrawal symptoms. 

Any advice? I'm really worried about my weight. I'm ballooning massively and can't seem to stop it and it's really getting me down. 

11 Replies

Hi, I think it takes a few weeks, maybe even months for some. I started to feel a little better after about 4/5 weeks. Good luck :-)


Thank you! I guess I am just being impatient then! :)


Strawberrysorbet, it usually takes 7-10 days to aborb Levothyroxine before it starts working and then up to six weeks to feel the full impact of the dose.  You should start to feel some improvement after 2-3 weeks but it can take several months after you are optimally medicated until most symptoms are resolved.


Thanks Clutter. Is it possible to calculate how much your FT4 should rise based on the dosage of thyroxine you're on or is this going to be different for everyone? I'm just wondering how much of a difference my 50mg is likely to make to my levels. 


Strawberrysorbet, I think it will be different for everyone and the variation in levels will depend on how undermedicated you are when your dose is adjusted.


Some symptoms go fadt others hang on for months ,in my case over a year for most but still got ataxia two years on. 


If you are on a low calorie diet, that could be working against you. You need calories to convert! It isn't going to make you lose weight at the moment, anyway. Just make sure you're eating good, fresh food. Nothing processed. :)


Really greygoose?! So are low calorie diets a bad idea? I am actually doing 5:2 but I increased it to fasting 3 days rather than the 2, because 2 days normally did nothing for me. Do you think I might be making things worse? If I increase exercise (which is difficult as I feel so tired) is that likely to help increase my metabolism? I really am at a loss as to what to do. I haven't noticed any difference at all in any of my symptoms and it's been over a week now. I hope I'm not making it worse through dieting?


Yes, dieting very possibly can make things worse. As I said, you need calories to convert the T4 you're taking (storage hormone) into T3 (active hormone).

And if calories are in short supply, what's available goes to essential activities like breathing and digesting, and heart beating, moving around etc. Conversion is way down on your body's list of priorities, funnily enough.

And, if you cannot convert your T4 to T3, you get more and more hypo, your metabolism therefore gets more and more sluggish, and you put on even more weight.

Exercising is even worse, because not only does it use up your precious calories, it also uses up what little T3 you do have. You've already said you can't exercise because you're so tired. Well, that's because you Don't have enough T3. If you exercise, you'll have even less. And then how will you manage the rest of your living, like keeping yourself clean, and feeding yourself? You can't. Just remember that every movement is exercise in the strict sense of the term - even just breathing.

It's low T3 that causes symptoms, not low T4 or anything to do with the TSH as doctors seem to think. So, the less T3 you have, the more hypo you are, the more symptoms you have, and the more difficult it is to lose weight.

So, at this stage in your journey, 'diets' and strenuous exercise are most definatley not recommended. You need plenty of good food and just gentle movement like walking or yoga, to keep you from rusting up!

To be able to lose weight, you need good levels of T3. And I bet yours are rock-bottom at the moment.

After just one week, you really can't expect anything much to improve. And trying to hurry things up, and taking short-cuts is just going to make things worse - remember the saying : more haste, less speed? Everything to do with thyroid is slow!

So, patience is the number one rule. Number two, is good nutrition. Your nutrients are probably rock-bottom, also. You should ask your doctor to test : vit D, vit B12, folate and ferritin.

When we are hypo, we usually have low stomach acid, which makes it difficult for us to break down our food and absorb the nutrients. However, those listed above (and some others) absolutely need to be optimal for your body to be able to absorb and convert the hormone you're giving it.

Which is another reason not to restrict your food intake. The less you eat, the fewer nutrients you have. And nutritional deficiencies will also make it difficult for you to lose weight.

So, it's not just a question of popping a little white pill every morning, and waiting for the miracle to happen, as doctors think, there are lots of other things to consider, too.

Hope I haven't over-loaded you with information, there. lol It's a lot to take in, in the beginning, I know. But we are always here, and you can always ask - and reask - any questions you have. :)  

1 like

Hi I started in t3 a few months back (self medicating ) I was told 1 per day forva week then up it to 2 a day on the second week then come off for ten days then repeat is this the normal for ppl just Im not sure as I feel tired and crabbie after a few days off being of them any advice x


I strongly recommend that you post your own NEW question.

It is unlikely that the people who are best able to help you will notice your response/question here.

When you do post your question, please add as much information as you can - it helps people to understand where you are in terms of treatment and can tailor their advice appropriately.


You may also like...