Would a 3.0 increase in TSH affect weight? - Thyroid UK

Thyroid UK

114,513 members132,882 posts

Would a 3.0 increase in TSH affect weight?


Hi everyone

I'm new here, although I have been hypothyroid for 7 years. I was diagnosed at 5.0 and have stayed in the 2s for years with 50mcg of Levothyroxine.

I've noticed symptoms over the year (hair loss, cold, weight gain, struggling to lose said weight) but my GP has put it down to age and perimenopause as I'm 44. Various doctors would not do another TSH test as I had one in July 2017.

I bypassed the Dr and rang Dr's receptionist to book a TSH test and thankfully GP didn't object- that was yesterday, the surgery rang today to say my TSH is 6.9 and I need a review- it's next Friday.

My question is, would this relatively small increase impact on my weight? I'm a stone overweight but 3 weeks of RELIGIOUSLY following Slimming World has resulted in a 1/2 pound gain! If so, how long will an increased dose take to work?

Many thanks!

6 Replies


You haven't given the range for your test result (ranges vary from lab to lab so we always need reference ranges with results), but TSH ranges don't go higher than about 5.

Your current TSH of 6.9 is over range and means that you are undermedicated. This will be the cause of your weight gain.

The aim of a treated hypo patient generally is for TSH to be 1 or lower with FT4 and FT3 in the upper part of their ranges if that is where you feel well.

You need an increase in dose of Levo of 25mcg now and retesting in 6 weeks to check your levels. You may possibly need a couple more increases to bring your TSH down to where you feel best, so ensure that you are retested every 6 weeks.

When having thyroid tests, always book the first appointment of the morning, fast overnight (as in delay breakfast until after the blood draw, you can drink water) and leave off Levo for 24 hours before the blood draw. This ensures that your TSH will be at it's highest which is needed when looking for an increase in dose or to avoid a reduction. *These are patient to patient tips which we don't discuss with doctors or phlebotomists.*

Jt92018 in reply to SeasideSusie

Thanks for the response ☺


The most common question on this forum is 'unexplained' weight gain.

The majority of doctors know NO clinicals symptoms of hypothyroidism which No.1 seems to be weight gain as it is distressing to people wondering what is going on as they've not changed diet etc.

You must realise that the medical profession seem to know the least thing about hypothyroidism just that TSH has to been reduced to somewhere in the range - which could be up to 5. We, the patients, are distressed that weight continues to increase.

First (hypo = low) thyroidism means we have too low an output of thyroid hormones so we are given levothyroxine (starting dose 50mcg) to raise it to a normal level for us. That means we feel well and are symptom-free.

Every six weeks we have a blood test with 25mcg increase until TSH is 1 or lower. Not higher.

Procedure for blood tests for thyroid hormones:-

1. The earliest possible appointment.

2. Fasting (you can drink water)

3. Allow 24 hours between your last dose of levo and the test and take afterwards.

This will give you more beneficial results and the aim is a TSH of 1 or lower with Free T4 and Free T3 in the upper part of the ranges. NHS rarely tests these but we have private labs that do home pin-prick tests if you wish.

Your GP should test B12, Vit D, iron, ferritin and folate. These too should be optimum not just in range.

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

You will require an increase in your medication to lose weight your TSH looks high.

It's nothing to do with your age I am 72 years old and feel well without a thyroid.

Ranges are needed too please.

I think that the short answer is “yes”, a slight rise in your tsh would account for your weight gain, Slimming World or no Slimming World. I joined this organisation before diagnosis and was accused of lying about my diet as I did not lose weight. It was not until I was diagnosed and medicated with NDT (privately) that I lost weight. I am on T3 only and have a tsh of <0.01 and have lost enough weight to keep me happy - 30lbs to date.

LAHs in reply to penny

I had the same story from NutriSystem. I put weight ON! Since I had followed their system religiously, to the very letter and they blast their "Money back guarantee" on the TV ads, I asked for my money back! I don't usually do that, I believe that a deals a deal and if I make a stupid error that's my problem. This time they had lied and then told my I was lying. Well I did get some money back but they stiffed me $90 and left me with all the wieght that I had struggled so hard for weeks to lose before I tried their method.

You may also like...