Thyroid UK
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Underactive Thryoid

New to having Underactive Thyroid.

Had two blood tests - Dec 2015 and April 2016 due to my late mother who was taking medication for under active and the results were on the borderline for under active thyroid. Only by my sis in law who is also under active said for me to get another blood test and should start taking Levothyroxine tabs and due to this result I am now taking 50 mg for which I stated taking 3 weeks ago.

Unfortunately have gained weight and feel self conscious about myself and constantly changing my tops to find out which one I will look ok in due to my stomach looking bloated when I am getting ready for work or going out and getting very frustrated with this. I suppose I will need to be patient and hope this will change. Will be having another blood test in July and need to make sure to ask GP for a printout of results for me to understand this. I had written them down when I wasn't able to be given these as a printout when I phoned my Doctors Surgery but was given them over the phone can't find where I have written this.

Has anyone else found this confusing and too much to take in?

2 Replies

Hi Seg,

OMG i'm completely with you there on the clothing situation. I tend to just live in black these days but even that is now problematic now weather is warmer.

I too have put a stone and half on and that was after i started on thyroxine.

I'm losing very, very slowly now on T3 but only have to look and breath at something to put 3lb on.

It is very frustrating and even now i'm on T3 it is a constant struggle so i won't lie to you and say it will just drop off.

Hopefully you'll be one of the lucky one that can start to lose weight once your on correct dose. Fingers crossed!!

Sparkly x


Welcome to the forum, Seg2306.

Many people aren't even aware they have a thyroid gland, let alone what it does, until they have thyroid dysfunction. It can be confusing at first. Being underactive can cause weight gain and swelling/bloating. It should improve in a few months once you are optimally medicated but you will probably need to diet and exercise to lose the weight you've gained.

For maximum absorption Levothyroxine should be taken with water 1 hour before or 2 hours after food and drink, 2 hours away from other medication and supplements, and 4 hours away from calcium, iron, vitamin D supplements and oestrogen.

It takes 7-10 days for Levothyroxine to be absorbed before it starts working and it will take up to six weeks to feel the full impact of the dose.

You should have a follow up thyroid test 6-8 weeks after starting Levothyroxine and after any dose adjustments. Arrange an early morning and fasting (water only) blood draw when TSH is highest, and take Levothyroxine after your blood draw.

Most people will find symptoms resolve after their TSH drops to around 1.0 with FT4 in the upper range but symptoms can lag a couple of months behind good biochemistry.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

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