Thyroid UK
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I just wondered, are some of us overweight because of hypothyroidism, or is it because we are taking

Levothyroxine? I really think/know my weight has piled on since starting Levothyroxine. I was never to bothered about weight etc. then I was diagnosed with thyroid problems and starting 125mgs of Levothyroxine, my weight has ballooned ever since. Anyone else suspect this?

10 Replies

Hi Dylansmum. Overweight can come from Low T4 to T3 conversion, the thyroid gland governs metabolism, if your metabolism is sluggish, weight loss will be difficult.

There are foods you can eat, that can help. Radish is a rich source of T3, Sweet potatoe and salmon is a good source of B5, which helps with cortisol regulation.

Dr Barry Peatfield an Endo and Nutritional Therapist, has a very good book called your Thyroid and how to keep it Healthy.

The book contains a lot of dietary advice. Dr Peatfield helped me, and I still see him

Hope this helps


It's extremely common to gain weight when hypothyroid because our metabolism has become extremely low. Levothyroxine can also be the cause too if you aren't on sufficient to raise your metabolism. Some doctors give us too low a dose and keep the TSH in 'range' when we may be better with a low or suppressed TSH. We usually feel o.k. when TSH is around 1.

This is an article the deceased Dr John Lowe wrote which I think will be informative for you.


That is my problem too, I was told the reason for my above waist expansion is down to taking thyroxine after my op for full removal of thyroid in May.

Initially I was taking 150 mgc and lost half a stone then my specialist put me down to 125mgc and I have started to put weight back on but am not happy about it either.



I suspect your thyroid hormone is low and you are under medicated.

Thyroid hormones are responsible for metabolism so low levels would slow everything down. .. Do you feel tired and cold..? ..

I have looked through your previous posts but can not find any reference to recent thyroid hormone blood test results .

Has your doctor tested your thyroid hormones recently.. ? / ? ...

Also has he tested Vit B12, Vit D, Folate and ferritin.. ? .? ..

Optimal nutrients and iron levels are required for thyroid hormone synthesis so it could be you are having enough meds but they are not converting into usable T3 hormone in your body.

If you post results complete with ranges (numbers in brackets).. members will comment.



Thank you all for your comments. No I haven't been to doctors for at least a year. No-one at the practice notices either! just keeps dishing out the pills! I have recently moved from the East coast way down south, to get a doctor here is a miracle, to get an appointment, you will get one maybe three weeks later, you are not allocated a doctor, it's just get to see whoever you can, so it's impossible to get to know a doctor and visa versa. I just can't see myself making an appointment, just to say " I am putting on weight"! when they are having big trouble getting GP's in East Sussex. xx


Dylansmum, you shouldn't say that, anyway. :) But you could say you haven't had a blood test for a while and you think you should have a test because you might need an increase in dose. In fact, I think you should. It's a very reasonable request.

And, by the way, Don't go eating large quantities of radishes! There's no T3 in them. :) Quite the contrary, they are goitrogenic, and could have an adverse effect on your thyroid if you eat a lot of them. They are very good for the health, contain lots of good things, but all things in moderation.


This happened to me, then I added t3 and put more on again!! 😭


My personal theory is that as levo is T4 alone (a storage hormone) it makes you fat because you store everything.


When I was first diagnosed with Graves Disease in January 2014 my endocrinologist advised that I would put on weight with Levotyhroxine. I have put on 1 stone since then. Although lost weight as I kept going overactive which causes weight loss. I am also trying to manage my weight but some days I pig out especially when I feel low or due to taking steroids.


Hi - I put on 2.5 stones in the 4 years before I was diagnosed as hypothroid (and felt as if I was at death's door). Once I started T4 my tiredness improved and weight stabilised, but I could not shift the 2.5 stones, in spite of trying Weightwatchers, which has always worked before.

2 weeks ago I started on a 25mcg daily dose of Tiromel, bought privately from Turkey. In 2 weeks, without changing my diet at all, I have lost 6lbs. I don't think Levo increases

weight, but it definitely does nothing for the slower metabolism you get with hypothyroidism. Other symptoms have not improved, but the weight loss alone is worth it.

2 things though - I have felt much better with Mercury brand T4, and there have been studies to show Levo causes polyps ( I have had 2 removed since being hypo).

I think that hormone levels are highly individual, and it might be worth trying at least another brand of T4.

All the best


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