Thyroid UK

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.

10 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.


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.

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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.


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