Thyroid UK
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Weigh gain worries

Hi, I'm very new to the forum and have recently had a thyroidectomy, I had the left half out in 2015 and the rest out July 2017. I wasn't given any medication following the first op and was told that my levels were fine (I believe my last test TSH was 0.7) although I felt rubbish and my hair was falling out.

Following this lates op I was started on a dose of 125mg and am now on 150mg after a visit to the consultant and GP who thought my symptoms were hypo, I take my medication at night as I was feeling quite disorientated taking it in the morning, this seems to have stoped now I'm taking it at night. (I realise it's early days as I only had my op on the 19th of July)

Now to my real worry, from a symptom perspective I think I've been hypo for a while, I've put on about 3st over the last 2-3 years, and I'm absolutely terrified of putting on more following my op, please could anyone advise me he best way to lose the weight I've already gained and prevent any further gain, I'm going for TSH blood tests in a couple of weeks, are there any specific add ons that I should ask for?

5 Replies

Welcome to our forum,

My personal opinion is that someone who has had a thyroidectomy should be given T4/T3. You have probably been given levothyroxine (T4) only.

Hypothyroidism does cause unexplained weight gain as metabolism has been dropping. Doctors blame many patients for 'eating too much' but that isn't the case.

Hypothyroidism means that our metabolism has become so slow and that our pulse and temp are usually low too but we don't realise that at first.

Blood tests should always be at the earliest possible, fasting (you can drink water) and allow a gap of 24 hours between last dose of hormone and the test and take afterwards.

This helps keep the TSH at its highest as it drops throughout the day and may prevent doctor adjusting your dose.

Ask if he will test T4, T3, Free T4, Free T3 and thyroid antibodies. He or lab may not as GPs have been told that TSH and T4 are sufficient. No - they aren't.

He should definitely test B12, Vit D, iron, ferritin and folate.

Always get a print-out of your results with the ranges for your own records and if you have a query you can post them.

You should have an increase in levo - 25mcg every six weeks until you feel better but doctor may stop when TSH is somewhere in range - it should be below 1.

As your dose is increased sufficiently your weight should begin to drop as your metabolism is raised.

Levothyroxine is T4 (inactive hormone). T4 converts Liothyronine (T3) Active hormone. So as you dose rises hopefully your weight will begin to drop.


Thanks very much


You need your FT3 tested. If your doctor is only testing the TSH, then he has no understanding of thyroid! The TSH is irrelevant, once you are on thyroid hormone replacement, unless it goes high. The most important number for dosing is the FT3.

Symptoms like weight-gain and difficulty losing it, are caused by low T3, believe it or not - and most doctors don't believe it! So, the only way to reverse the situation is by optimising your T3. But, if it's never tested, you will not know if it is low, high, or what it is. You also need your FT4 tested, to see if you are converting the T4 you're taking - levo, a storage hormone - into the active hormone, T3. But, if you don't have the two tested at the same time, you will never know. If you can't convert, there's no point keep increasing the levo. It's not the levo that makes you well. You need to find out why you aren't converting.

There can be several reasons for bad conversion. One of them is dieting! If you do not ingest enough calories, you will not be able to convert T4 to T3, so instead of your low-calorie diet making you lose weight, it will make you put more on. Another reason could be strenuous exercise, because it uses up your calories. It also uses up what little T3 you've managed to convert.

Other reasons include nutritional deficiencies - have you had your vit D, vit B12, folate and ferritin tested? If not, ask for those, too. And it could be due to having Hashi's - have you had your antibodies tested?

So, to recap, here are the tests you need :






vit D

vit B12



But, it's very doubtful that your doctor will test all of those. So, have you considered private testing?

1 like

I've not thought about private testing until I read some of the threads on this forum, I'd be happy to do it I'll probably just need some help understanding the results


No problem with that! Plenty of people here to help you.

Details of private tests are on the Thyroid UK main page. :)


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