Levothyroxine side effects: First - Hello guys... - Thyroid UK

Thyroid UK

120,433 members140,200 posts

Levothyroxine side effects

Maniacos profile image

First - Hello guys. This place looks very helpful and nice and I'm glad I found it.

Let me tell my story:

3 months ago I was diagnosed with Hashimoto (yay). I'm 38, male.

My thyroid gland looks healthy and my TSH was 6.2.

My doctor prescribed me 50mg of Levothyroxine.

Almost immediately after taking the first dose (well, next day etc) I started to feel worse. My legs got stiff and my stamina was like: 20 minutes standing tops, 1km walk tops. Then I needed to sit or lay down or I will fall.

My doctor advised me to start taking another Levothyroxine brand. From another country. She said that I'm probably getting a bad reaction to the fillers or the way Levo was produced. I needed to clear my body from the old Levo to start the test.

The problem:

I'm 8 days OFF any Levo and I'm still stiff and tired == the side effects are still here.


Is this normal? How long?

Thank you for your time and help!

Best regards

28 Replies

Perhaps they're not really side-effects of the levo. Perhaps they're symptoms of the hypo. It's not unusual to develop more hypo symptoms when we start taking levo. They usually disappear as the levo is increased.

Personally, I don't think you should have stopped the levo, but made a straight swop. Things would have sorted themselves out anyway, if your aches and pains were reactions to the fillers.

Thanks for the fast replay!

I was taking Levo for 3 months with this same idea "to adjust to levo" "temp side effects" etc. It didn't work. I think my dose is correct. It was confirmed by 3 doctors. Taking blood tests, age and weight. It's so weird, and they don't go away :(

greygoose profile image
greygoose in reply to Maniacos

How much are you taking? It would be very unusual to get to your optimal dose in three months. Do you have copies of your blood test results? If so, post them here, with the ranges, and let's have a look. Smells a bit fishy, to me! :)

Maniacos profile image
Maniacos in reply to greygoose

50mg for a 72kg male with "healthy thyroid gland".

Blood tests:

3 months ago - TSH 6.2 (1st diagnose - just a bit tired, nothing major)

after 2 months on 50mg - TSH 4.39 (the side effects present)

my doctor changed the brand and lower the those to 25mg every other day with the idea to "adjust" and test another brand

A month later - TSH 6.7

my doctor told me to stop for a week and start 50mg again with another brand (from a different country).

8 days later - still side effects


greygoose profile image
greygoose in reply to Maniacos

50 mcg is just a starter dose. Your doctor - who obviously knows nothing about thyroid - made the mistake of starting you on too low a dose. It's very, very rare that anyone would be well on just 50 mcg.

As for your gland being healthy, it may very well be, but it's been damaged by the Hashi's, or you wouldn't have had a TSH of over 6. Therefore, you need thyroid hormone replacement of some kind. Once you are on thyroid hormone replacement, the TSH should come down to 1 or under. If your TSH is still 6.7, you are still hypo and under-medicated. But, you have ignorant doctors.

So, when are you going to start on a new brand of levo?

Jazzw profile image
Jazzw in reply to Maniacos

Your doctor’s an idiot. How did he conclude you have a healthy thyroid gland when you have Hashimoto’s??

50mcg is a starter dose. Most on levothyroxine don’t start to feel better until they’re on a sufficient dose for the TSH to fall below 1.0. So instead of cutting your dose in half, your numpty doctor should have increased it.

Find a new doctor. This one will leave you ill for a long time.

Maniacos profile image
Maniacos in reply to Jazzw

@greygoose weird. 3 doctors said - 50mcg is okay. hmm

@Jazzw - "healthy" because on echograph it was looking okay. Yes Hashimoto is there, but not structural damages

shaws profile image

I am sorry you've been diagnosed as being hypothyroid. Your TSH was rising and it is correct that the doctor prescribed levothyroxine. Unfortunately, especially if you are in the UK, it would appear that many doctors don't know much more than the TSH result and yours is rising.

You actually have an Autoimmune Thyroid Disease (Hashimoto's) which means you have antibodies in your blood that attack your thyroid gland (they wax and wane) and you become hypothyroid. Treatment is the same, ie. levothyroxine and your doctor should not have told you to stop taking it i.e. there's no need to 'clear it' as the only difference is in the fillers/binders of levothyroxine and you actuall need the hormone within it, which is T4. T4 is an inactive hormone and it has to convert to the Active Hormone which is T3. It is T3 which is needed in our millions of T3 Receptor Cells. T3 enables our body to function - we are dealing with hormones and not medication - and our heart and brain need the most.

In many countries we'd be diagnosed if our TSH goes above 3. In the UK most doctors seem to be told that the cut-off for prescribing is 10 but they are not taking into account the clinical symptoms.

Change your make of levothyroxine and there's a few options. Stay on it as it is not a miraculous change as your GP seems to think. It takes six weeks at least for it to build up in your body and I shall give you a list of clinical symptoms.

You can help reduce the antibodies that attack your gland by going gluten-free.

All blood tests for thyroid hormones have to be at the very earliest, fasting (you can drink water) and allow a gap of 24 hours between last dose and test and take afterwards. This helps keep the TSH at its highest and prevents doctor from reducing dose.

A Full Thyroid Function Test consists of TSH, T4, T3, Free T4, Free T3 and thyroid antibodies. The aim is a TSH of 1 or lower, with a Free T4 and Free T3 in the upper part of the ranges. A Full TFT is rarely taken by the NHS but if you want, we have some private labs that will do so. You don't need any at present and hopefully your symptoms will begin to resolve as dose is increased. It isn't a quick procedure - it is slow and gradual.

GP should also test B12, Vit D, iron, ferritin and folate. Everything has to be optimal.

Always get a print-out of your results, with the ranges for your own records and you can post if you have a query. Ranges are important for members to comment upon the results as labs differ.




Thanks for the replay shaws!

I'm not in UK.

A bit more results:

Anti TPO: 411.7 (in the beginning, this is why diagnosed with Hashimoto)

FT4: 12.40 (this is my latest result after the 3 months)

shaws profile image
shawsAdministrator in reply to Maniacos

When you give your results, the ranges must also be shown due to the fact that labs have different machines and therefore ranges are also different. Ranges enable members to respond to the results.

It is a learning curve but hopefully you'll soon feel much better as dose is increased.

Maniacos profile image
Maniacos in reply to shaws

Yes, that was useless info. Sorry.

Here is better one:

The beginning (Hashimoto diagnose):



After 2months Levo 50mcg:


After another month on 25mcg every other day:


and TSH - 6.77

shaws profile image
shawsAdministrator in reply to Maniacos

You are on an insufficient dose to have a TSH above range. You need 25mcg increases every six weeks, after a blood test until TSH is 1 or lower. The FT4 and FT3 should be in the upper part of the ranges but these are rarely tested.

Maniacos profile image
Maniacos in reply to shaws

Thanks. So my "side effects" are because of the small dose? The stiffness the super weak muscles?

Your dumbo doctor is messing about with your dose and this will mean you stand little chance of stabilising your condition. If you keep chopping and changing you are going to make yourself even more unwell. Being in the ‘normal’ ranges means nothing - you are not normal - you have Hashimoto’s and cannot measure your recovery in this way. If you have symptoms of hypothyroidism you are not on adequate replacement. There are many many symptoms as the condition affects the ability of every cell in your body to produce energy. Here is a useful checklist of symptoms. thyroiduk.org.uk/tuk/about_...

You should use your symptoms to help you get to the optimum dose for you - that is when they are relieved. You’d be very lucky if you got there in 3 months and with the guidance of your rather ignorant GP. I’m 3 years since diagnosis and getting there, but not at optimum yet!

Use this site to develop your knowledge and understanding of your condition - it is much more complex than GPs would have us believe and can have a long term detrimental effect on your health. Also, having Hashimoto’s is different to just having an underactive thyroid, but GPs may treat it as the same as they don’t understand it. Good luck on your journey - I hope you get to the destination faster than I have, but, believe me and the others on here, it is not s straightforward path for lots of us, unfortunately.

I must say, I'm completely confused. My Hashimoto symptoms before taking Levo were "easily tired, nothing major" "falling hair, a small amount" "blotchiness on the face". The moment I started Levo I got new ones - super easily tired, stiff legs. So I assumed (and my doctor) I got side effects from Levo. What you are suggesting is that those "side effects" are due to the low dose? And by starting Levo I entered some new stage "if you don't take enough of me you will feel ill, If you never started taking me, you will be better (but not perfect)". I will seek a new doctor for sure. I just miss the logic :(

It could be the Levo and if so trying another brand is a good idea. However, uou may have hypo symptoms that you assume are something else. I did before diagnosis. And if you are Hashimoto’s your symptoms will get gradually worse as your thyroid is being slowly destroyed despite looking okay at the moment. Also, if your thyroid is still partly working (though not able to produce enough T4 in its own, hence the raised TSH) and responding to the TSH from the pituitary, then as Levo lowers your TSH, your own thyroid may contribute less, so you need an increase in Levo. It’s really not contradictory, but not as simple as your logic either, if you read up about your condition it will help you to understand why people are making the comments they are to help you. Unfortunately, you will not get better, only worse - it is a chronic condition. If you are unhappy with being treated at this point, you don’t have to be, but your results show a thyroid starting to struggle.

Maniacos profile image
Maniacos in reply to MissGrace

Thank for the reply! I want to be treated, I know it needs to be done. I just can't find the logic, why Levo makes me feel worse. My logic is that even with low dosage I need to start feeling a bit better and make the dose bigger to feel perfect. But probably you are right and I don't know enough on the topic. It's just frustrating :(

Jazzw profile image
Jazzw in reply to Maniacos

I’ll try to have a go at explaining - see if this makes sense...

You are suffering from hypothyroidism - a TSH of 6+ confirms that. No matter how healthy your thyroid looks on a scan, it’s failing because although your pituitary gland is shouting at your thyroid (TSH is made in the pituitary and stimulates the thyroid to produce thyroid hormone) your thyroid can’t make enough.

However, your thyroid - untreated - has probably been making more than 50mcg of T4 a day. Possibly not much more, but more than 50mcg. What sometimes happens when we start taking thyroid hormone replacement is that your own thyroid stops bothering to make any at all. So your body is, in effect, feeling the net result of having access to less thyroid hormone - which means an increase in hypo symptoms.

That’s why an increase in dose is required - to make up for your thyroid no longer making any thyroid hormone at all.

Maniacos profile image
Maniacos in reply to Jazzw

This makes sense! Thank you Jazzw! I think I understand now. I will try another doctor after NY. Thanks again for the explanation!

Jazzw profile image
Jazzw in reply to Maniacos

No probs. As you may have gathered, many doctors just don’t understand the condition at all. They think treatment is just like the treatments they provide for other conditions - like high blood pressure, for example. Give the patient a pill and watch that blood pressure come down, and if it doesn’t, try a different pill. Well, hormonal conditions are not quite the same. I think if doctors stopped to think about it, they’d get why it’s not the same - we do, after all! - but they have very little training on the thyroid in med school. Well, very little training on hormones full stop, to be honest. Synthetic hormones can’t be taken like supplements. They don’t just top up what your body can make - they tend to replace what your body makes after a short adaptation period.

PS - high blood pressure, high cholesterol, digestive issues, joint pain (and many many more) are all undertreated hypothyroid symptoms.

Maniacos profile image
Maniacos in reply to Jazzw

" They don’t just top up what your body can make - they tend to replace what your body makes after a short adaptation period." This is why I was so confused. I expected "top up" :) Again thanks for all! This goes to all people that tried to help, thanks guys!

SlowDragon profile image

Also ask your doctor to test vitamin D, folate, B12 and ferritin

These are often too low with Hashimoto's, and especially if have been under medicated, as you have

Come back with new post once you get results and ranges

Levothyroxine should be started at 50mcg, bloods retested after 6-8 weeks and dose increased in 25mcg steps, retesting each time. This continues until TSH is around one and FT4 towards top of range and FT3 at least half way in range

As others have said, any dose of Levothyroxine tends to turn our own thyroid hormone production off. So you often don't start to see benefits until had 2 or 3 dose increases

Most patients eventually need somewhere between 100mcg and 200mcg Levothyroxine. But the body has to adjust slowly.


List of hypothyroid symptoms


Hashimoto's affects the gut and leads to low stomach acid and then low vitamin levels. Low vitamin levels affect Thyroid hormone working

Poor gut function can lead leaky gut (literally holes in gut wall) this can cause food intolerances. Most common by far is gluten.

According to Izabella Wentz the Thyroid Pharmacist approx 5% with Hashimoto's are coeliac, but over 80% find gluten free diet helps, sometimes significantly. Either due to direct gluten intolerance (no test available) or due to leaky gut and gluten causing molecular mimicry (see Amy Myers link)

Changing to a strictly gluten free diet may help reduce symptoms, help gut heal and slowly lower TPO antibodies

Ideally ask GP for coeliac blood test first






Maniacos profile image
Maniacos in reply to SlowDragon

Thank you for the replay! There is something I still don't understand. You and others said, "any dose of Levothyroxine tends to turn our own thyroid hormone production off." So this means that every person that started Levo experienced my super big tiredness and stiffness. People start with low dosages. And yet I can't find this anywhere. Yes, people are a bit tired, but mine is a total showstopper. How this is explained?

SlowDragon profile image
SlowDragonAdministrator in reply to Maniacos

As a young man you are not the usual profile. A young male has a higher metabolism

A doctor can choose to start someone on a higher dose, up to 100mcg

But it's more usual to start more cautiously at 50mcg or 75mcg

Low vitamins can significantly affect this too

Your reaction is not uncommon.

Gluten intolerance is extremely common too

Maniacos profile image
Maniacos in reply to SlowDragon

Interesting. It answers some questions. I'm amazed my doctor didn't think of that. I'm getting a new one after NY. Thank you very much for the info and happy holidays!

SlowDragon profile image
SlowDragonAdministrator in reply to Maniacos

Many medics only have the scantiest of knowledge of how thyroid works

Any replacement thyroid hormones do not add to your own existing thyroid production.

Taking any thyroid hormones will always turn your own thyroid production down. So frequently starting on 50mcg (or worse 25mcg) will significantly reduce overall thyroid hormone levels.

It is very difficult sometimes to work out what is happening plus we have probably had different journeys to reach a good spot but something you will discover on the way up to wellness is that when we increase a dosewe immediately feel the difference but it can be short lived as it's not a high enough dose to keep your body satisfied for long and I expect this is the feeling you have been experiencing so far. Ok as you increase your dose the wellness feeling may well make you feel better a bit longer but keep increasing until your bloods are good for you. If you are unsure then by all means print your results and hopefully you will receive good advice. But it's a long journey and so patience is important word to take onboard.

Docotorson the otherhand don't always understand what is happening and why. I am tested outside the area where I live but I'm always having to remind her that the ranges are very different from what she is used to. So always give your ranges when you give any results. If you look at the Thyroid Uk site-they run this forum, there is a lot of info to help you move farward. Some things are how to do things but others that you mustn't do and these can make a difference of what is actually happening. Shout out if anything you don't underdtand and I'm sure someone will help

Maniacos profile image
Maniacos in reply to silverfox7


You may also like...