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Thyroid UK
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Weight gain on Levothyroxine

Has anyone managed to lose weight on Levo? I have been a bit overweight for a while and couldn't lose any. I hoped I might be able to once I was diagnosed hypo last May but my weight seemed to increase. My Dr just shrugged when I told her. (Although she has said in the past that I would feel better if i lost a bit of weight) Recently the pounds seem to be piling on despite the fact that I don't eat a lot. I have had to buy clothes a size larger having been size 14/16 for the last thirty years.. I'm sure I'm still under medicated (75 mcg,) I'll post latest blood results when I get them, I was only given tsh last time, 2.9 so told satisfactory, Dr didn't need to see me, despite the fact that I still have multiple symptoms. I was wondering if it would be worth paying to see a Dietician as I feel uncomfortable now and think I might have more energy of I could lose a stone or two. I hope some of you fellow sufferers can offer some hope. Thanks.

28 Replies

A TSH of 2.9 may be 'satisfactory' to a doctor but, in reality, once diagnosed as hypothyroid the aim is a TSH of 1 or lower.

I'd ask your GP to increase your dose and you can say you've had advice from the NHS Choices for help/advice on dysfunctions of the thyroid Gland.

When we reach an optimum dose of thyroid hormones (levo or others) it raises our metabolism to normal and we should be able to lose weight.

Weight gain is the commonest question on the forum and it is because hypo means that our whole metabolism is 'slow' and weight is gained.


Hi do you have a link to NSH choices with that information please? I’ve been looking and all I can find is is following.

In most cases, suppressing thyroid-stimulating hormone (TSH) using high dose thyroid replacement therapy should be avoided because it carries a risk of causing adverse side effects, such as atrial fibrillation (an irregular and abnormally fast heart rate), strokes, osteoporosis and fracture.


I would like to point my Doctor to the information you gave if you have a link?


I disbelieve the following "In most cases, suppressing thyroid-stimulating hormone (TSH) using high dose thyroid replacement therapy should be avoided because it carries a risk of causing adverse side effects, such as atrial fibrillation (an irregular and abnormally fast heart rate), strokes, osteoporosis and fracture."

Why then do those patients who have had Thyroid Cancer be permitted to have a suppressed TSH. Would there not be an outcry if suppression caused these effects?

I believe they are scare tactics and people may develop due to too low a dose of thyroid hormones to keep the TSH somewhere in the range (up to 5+) and we have to try other thyroid hormones which are not now prescribed by the NHS due to antics such as :-


The above critique was made by one of our Advisers before his death and despite three yearly requests for answers they point-blank ignored his scientific Rebuttal.

The real fact is that NDT has been in use safely and without blood tests since 1892. It was only about ten years after levo was introduced that 'new' diseases were named, i.e. fibro, CFS, and ME.


We on this forum may be mainly uneducated and unknowledgeable about dysfunctions of the thyroid gland but, again, so are many Endocrinolgosts and also doctors.

They believe it is soooooo easy when patients sit in front of them explaining their disabling symptoms - and who are very suprised they actually feel worse than before they were diagnosed. Doctors will give additional prescriptions for clinical symptoms (they know none at all) but if thyroid hormones are too low a dosage this can make us feel bad and symptoms aren't relieved.



Thank you 😜


Most patients on Levothyroxine need TSH below one and FT4 towards top of range and FT3 at least half way in range to feel well

Low vitamins are common as result of under medication

For full evaluation you ideally need TSH, FT4, FT3, TT4, TPO and TG antibodies, plus vitamin D, folate, ferritin and B12 tested

Do you know if you have ever had thyroid antibodies tested? If high this is Hashimoto's also called autoimmune thyroid disease

See if you can get full thyroid and vitamin testing from GP. Unlikely to get FT3

Private tests are available


Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have money off offers.

All thyroid tests should be done as early as possible in morning and fasting and don't take Levo in the 24 hours prior to test, delay and take straight after. This gives highest TSH, lowest FT4 and most consistent results

Link about antibodies


Link about thyroid blood tests


List of hypothyroid symptoms


Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.

Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor

please email Dionne:

Always take Levo on empty stomach and then nothing apart from water for at least an hour after. Many take on waking, but it may be more convenient and possibly more effective taken at bedtime


Many people find Levothyroxine brands are not interchangeable. Once you find a brand that suits you, best to make sure to only get that one at each prescription. Watch out for brand change when dose is increased


I should think it would be a waste of money going to see a dietician. Quite apart from the fact that I have absolutely no faith whatsoever in dieticians, your weight-gain is nothing to do with what you eat.

Having low T3 - which you more than likely do - will lower your metabolism, of course. But on top of that, hypos usually suffer from a delightful stuff called 'mucin', a mucousy substance that collects under the skin and holds water. And, no amount of careful eating/dieting is going to remove that! What is going to help with it is optimising your FT3 and your vitamins and minerals - it's not just about hormones. But, I wouldn't expect your doctor to know anything about that, nor any dietician. And putting you on a low-calorie diet is just going to make things worse. You need calories to convert the T4 (levo) you're taking, into T3. So, the odds are, you need to eat more, not less. :)


I lost 2.5 stone with the help of a nutritionist who worked out of my gym, having failed to lose any weight when going it alone. It all depends on the nutritionist or dietician of course (a dietician is theoretically more highly qualified than a nutritionist). Some have good knowledge around thyroid issues, and some (most I imagine) do not.

You certainly need to get your meds as optimal as you can, and I would also agree that you may well need to eat more. My nutritionist told me to always eat before I was hungry, and plan ahead what I was going to eat, and I believe those points were fundamental to my success. I was always having some healthy snack or other. They felt like they kept my metabolism running faster, and stopped me getting hungry & consequently overeating. Aiming for fairly steady blood sugar levels is good too, and I completely eliminated and artificial sweeteners and processed sugars and limited fruit o 2 serving per day. I also stopped drinking alcohol for 6 months. I didn't drink much before, but I did find that the empty calories it contains had a negative effect on my weight.

I weighed & wrote down everything I ate (my own decision) - which I found made me consider what I was about to eat more carefully, but I am aware that sounds a bit extreme. I plotted my weight on a graph, so that even if it went up for a few days, I could always see the general downward trend at a glance which kept me motivated. She told me not to restrict my calories, but to eat wholefoods as much as possible. I my case, I found that it didn't make much difference if I restricted carbs or not, but I suspect that this varies from person to person. Even if you are not gluten free, bread is a definite no no!

My nutritionist gave me some good advice about vitamins, was willing to do research too, and helped me to keep focused on my goals. I felt like I was answerable to someone other than myself. I saw her once a month at most, but she used to drop me emails to ask how I was getting on, which I found helpful.

If you do decide to see someone, I would suggest that apart from making sure they are thyroid aware, you choose someone who you think you will like, as childish as it seems, I'm sure some of my success was down to wanting to please the nutritionist.

Exercise will be a big element too, and I found lots of walks outside really helped. Not only is it aerobic, which I believe improves conversion, but it also makes you feel good & helps to generate some vitamin D. If you can rope a friend or partner in to those too, so much the better.


Thank you for your positive reply. I am well aware of the need to get my dosage correct and have read Dr Toft's hypothesis on here many times but have been unable to find it anywhere in writing. I bought the recommended book Understanding Thyroid Disorders by Dr Anthony Toft, and read it cover to cover. NO mention of tsh needing to be less than 1. I be!ieve this is not included in the current edition, has he changed his mind? If I am going to challenge my GP I shall need properly documented information..

I congratulate you on taking positive steps to lose weight. I shall definitely try the same. Unfortunately, I can't exercise as I am disabled but I move as much as I can.


Can you do any other sort of exercise? Yoga? Swimming? Perhaps. Exercise can be anything which gets your heart rate up a bit, and for weight loss, slow and steady is useful.


I do some exercises in our pool in the summer but only to keep my joints moving. I don't think it raises my heartrate. Rescuing mice from my five cats does that!


Even going for a gentle walk raises you heart rate & boosts your metabolism.


Sadly, only if you can walk!!!!!! I can manage a few yards, painfully!


That's shame. I would think some good nutritional advice could be useful then. If you have limited mobility, that in itself will affect your digestion.


I hope this helps I am just figuring this out myself. I lost my thyroid back in 1996 due to thyroid cancer at the age of 19. While I was young I didn't have insurance and I rarely got to take my levothyroxine since I couldn't go to the dr. I would take about 2 months of meds a year. I did that until I was in my late 20 and during that time I stayed thin. I was at the time 5'9 127lbs and underweight sometimes I would go up to 135. We in my late 20 I started taking it more. The first time I took it straight I took it for 6 months and ended up gaining 50lbs. I stopped taking it for a period of time and started losing some weight but never got close to my pre-weight before I started taking it again. I ended up getting to 200lbs. When I was off my meds I would go back down to around 275 and then would shoot back up. I never thought that it would be my medication. I thought it was because I was getting older. So when I was 32 when I divorced my ex-husband and was still right around the 200 mark but I had lost an inch over time due to back issues. Anyway, I got medical and started taking my thyroid medication again and got up to 230lbs. That lasted several months and things fell apart for about a year and a half and I stop taking my meds again. I dropped down to 189 during that time and managed to get my on insurance due to pain issues and heart issues. So back to the dr I went was diagnosed with Aggressive RA, Fibromyalgia, 50% spondylolisthesis, SI Joint Dysfunction, Hip Dysplasia and Neurocardiogenic Syncope. So I was put on much medication this was back in 2013 including thyroid meds again. During this time until about 2.5 months ago now I am 41 I stopped taking my thyroid meds again. I ended up getting up to 322lbs at now 5'8. So 2.5 months ago I stopped taking it. I lost 44lbs in 2.5 months. But again I wanted to test it to see if it was the medication. Again I started taking it that was not even a month ago. I started taking it again for 2 weeks and during that time I put back on 15lbs. So I went back off again and then my weight when backdowns and plus some. I lost another pound this morning. so right now my weight is 284.4. In April I was 322lbs. I had lost a total of 47.6lbs in 3 months since then. I know I still have to take it but I will do like I did in my younger days and somehow balance taking it with my weight so I don't end up dying from no thyroid. I hope this info helps someone and don't end up making the mistake I made for many many many years.


Hi teresa7676

Im confused..are you saying you put on weight taking thyroid medication? And you lost weight by not taking it? Are you not taking thyroid medication now?


True i put on 200lbs taking it and once i stopped i lost 47.6lbs as of yesterday in 2.5 months. I went back on my meds half way and put on 15lbs. But stopped again lost the 15lbs plus extra and still going down. My eating nothing has changed and I cant excersize. It took me over 20 to figure out it is the meds indeed. Right now i am not taking them, but i know i will at some point I have too to live. But it just wont be no more then a month at a time.


Crikey. What does your doctor say about this?


I stopped seeing a dr thats why i stopped my thyroid meds, i lost my insurance. I still have my levothyroxine just not taking it at the moment. I did this in the past for going on 10 years was always thin till i took it.


Oops I meant March not April, I tried to edit but it wouldn't let me submit.


I’m in exactly the same position - my TSH WAS 0.2 now it’s 2.5 and have put on 2 stone!! Doctors just say it’s within NHS guidelines and not happy to increase my level. I’m on 125mg one day and 100mg the next . Just started the 12 week eating plan and hoping to lose some weight!!


Mine is 125 mcg been on the same dose for a long time


Sorry to chime in sueD9 but couldnt help thinking your situation is not the same as Teresa7676. Teresa is saying her weight is going up taking the medication, whilst yours is going up taking the medication it is because your dose is not optimal, i expect you felt better with a TSH of 0.2 than you do with a TSH of 2.5. i think you will struggle to lose weight in this scenario. I would go back to your GP and tell them you want to increase your dose to see if you feel any improvement if this GP refuses make an appointment with another one until you get what you need. Perhaps try 125mcg everyday and get re-tested. This is what i do with mine...i try and keep my TSH below 1 not that you should adjust your medication by the TSH number...it should be by how you feel.

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Thanks lc1973 - you are right . I’ve just switched GP’s so I think I will make an appointment to discuss my levels . My weight was definitely better when I was having 125mg every day. Thanks for your advice 😀


Yw, hope you can find what works for you


Im not suggesting to stop meds like i have. Im saying the weight gain can be very real. And being overweight hurts me physically and diabetes runs in my family. For me this is my choice. I tried and tried to lose weight even had my dr stumped and now I know why. Again i am not encouraging it but putting info out there.


Not matter what med you take if you don’t watch what you eat and or exercise you will not loose weight .


You are wrong on this, those pills killed my metabolism. I am now down 50.2lbs as of today no diet no exercise. I cant exercise till I lose weight due to being aggressive RA and risking tearing my joints up.

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I’m doing very well with Levo ! And I’m just sharing my opinion .

I tried with other hormone replacements .

And when I say watch what you eat I mean exactly that .no gluten!

I hope your metabolism gets back to work

Try also lots of spring water oatmeal ,cayenne peper , ginger , cinnamon , green tea , those are excellent improving metabolism also .water exercises if posible .

Improving your adrenal system will help too .best of luck !


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