Thyroid UK
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Levothyroxine - does a low dose contribute to weight gain


I was first diagnosed back in 2005, (age 45) after visiting the Dr with weight gain, and severe itching of my arms, I was told then that I my thyroid could have been underactive for the past year (maybe more). I had previously been a size 10, using the gym, enjoyed going out (normal life). I gave up work in 2007, as the ability to concentrate, control the itching of my arms, I was prescribded various anti histamines (all made me sleepy) I felt at the time it was leave or be sacked.

My weight continued to increase, as did my dress size, by 2013 a size 16/18 , memories of the gym long gone. All symptoms were continually reported to the Dr, queries over my ever increasing size were I felt brushed aside, and i was told oh it’s ok!! I used to research and arrive at appoints with various findings , but felt that no notice was taken.

In Feb 2015 I had my gall bladder removed, changed my diet ( I am now gluten free) and over 18 months lost a significant amount of weight (back to a size 10/12) walking /cycling and feeling human again.I even contemplated looking for a job. That wasn’t to last long, as my bloods showed my Levothyroxine was now to high (October) and has been reduced by half (currently on 75mg) the weight is increasing again, now a size 12 verging on 14, and the same symptoms of itching is back, (no antihistamines this time - but a nerve suppressant has been prescribed,) I hope to get an appt in the next week to discuss this again.

If (I think) the problems of itching, lethargy etc went away when I was on the higher dose should I have to take extra medication (with it's own side effects) to deal with it. Wouldn't it make some sense to increase (even by a small amount) the dose of Levothyroxine?

The last visit to the Dr’s was the first time I had been shown my blood test/ hormone levels, and I didn’t think to ask for a copy, I am hoping for an appt next week to a) discuss the weight gain(again) b) the itching and other issues (I feel are connected) and c) ask for a copy of the results.

2016 was the best year I’ve had since being diagnosed, people I hadn’t seen in years (no desire to go out) commented on how I was the person they used to know, which was exactly how I felt – the person I used to be.

I hope all that makes some sense, another thing I struggle with is always getting things verbally or written to make sense!!

Would love to know what any of you think I could do next?

7 Replies


Welcome to our forum.

Most hypothyroidism is caused by Hashimotos, an auto immune disease that attacks and destroys the thyroid gland. Obtaining and posting your blood test results, complete with ranges (numbers in brackets ) will enable members to comment.

You sound under medicated as weight gain is a classic symptom of low thyroid hormone as is gall bladder problems.

Low thyroid hormone will slow down the whole liver metabolising process of filtering toxins and cleansing the blood. By products dumped into the gall bladder (to help the body get rid of them) become congested as the gall bladder slows and bile becomes thick due to the inability to emulsify the fats.

Having your gallbladder removed will only prevent further gallbladder issues but does not correct the root of the problem. Food has to be broken down into things like amino acids (from proteins), fatty acids and cholesterol (from fats), and simple sugars (from carbohydrates), as well as vitamins and minerals.

Bile is made in the liver, then stored and released by the gall bladder, and pancreatic enzymes (released by the pancreas) includes amylase, protease and lipase. Lipase is responsible for digesting fats and works with bile, breaking the fats down which can be absorbed into the blood stream and stored in the liver for energy.

Adequate bile is (indirectly) required for good thyroid hormone synthesis as are stomach acid and digestive enzymes. Inadequate amounts can inhibit digestion of essential fatty acids, the absorption of improperly digested fat globules, raising cholesterol levels and leading to deficiencies in fat-soluble vitamins (Vit A, E, K and the all important Vit D ! ! ..)

I am a Hashi sufferer and suffer from a thick gooey saliva problem and have investigated the whole digestion process in relation to hypothyroidism and gut//digestion issues.

Itching could be histamine intolerance as plays an important role in our bodies inflammation when related to allergies. It is broken down in the gut & liver but when you have too much due to allergies (possibly initiated and perpetuated by the sharpened over active immune responses to Hashimotos ? ? ..) .. your body is unable to break it down and this results in histamine intolerance that can trigger further allergies.

Histamine also acts as a neurotransmitter regulating sleep and stomach acid and is released when the body needs water, salt or potassium. There are four types of histamine receptor cells (H1R, H2R, H3R, and H4R) & each influences different systems of the body.

Histamine intolerance is not recognised by the medical profession, much like adrenal fatigue but is common in hypothyrodism. It results when there is an imbalance in accumulated histamine because of the body’s inability to break it down or degrade it and the body responds with many symptoms that mimic an allergic reaction. Unless histamine is controlled, symptoms may become progressively worse.

All processed foods should be avoided as should fermented as histamine is a byproduct of the fermentation. I always sneeze & get a blocked-up nose during the night after drinking wine & eating Chinese takeaway ... . there must be a moral to this story there somewhere . . :o))) . . ! ! ! ...

Both histamine intolerence and hypothyroidism will discourage adequate stomach acid levels and supplementing Betaine HCL with Pepsin will replace missing gastric acids helping gut inflammation. I also supplement digestive enzymes and bilary support. (Do not use Betaine with NSAIDS or if you have stomach ulcers..) ..

Histamine travels in the blood stream so can affect any part of the body which becomes reactive as is stuck in a chronic state of immune system overload, (possible) adrenal fatigue, (possible) gut dysbiosis & impaired digestion and definite inflammation, The aim is to calm all immune responses (reducing inflammation) so your body has a less reactive response to things it doesn't like . .... . as apart from an unpleasant snotty nose, itchiness, etc, any inflammation has a profound effect on ALL aspects of thyroid metabolism and physiology.

Testing your Diamine oxidase activity will give you an idea of your histamine responses.I supplement Curcumin, Kaprex A1 (containing HOPS) and Eskimo Fish Oils and keep all nutrients optimal.


This link actually refers to asthma studies but demonstrates the important role that Histamine plays in the regulation of the immune system.


Histamine & thyroid connection



Suzy Cohen advises on Histamine.

Histamine Intolerance


Thanks for the response radd, I used to describe the itching as having something crawling about under my skin, convinced for a while that we had an infestation of something we had new bed, bedding etc nothing changed, it does start around the joint in my wrists, elbows and/ or shoulder.

I have also found all the blood results online - had no idea they were there!! So hope this isn't too much to decipher:

03 Oct 06Serum free T4 level13.6 pmol/L10.8 - 19.3pmol/L

19 Dec 06Serum free T4 level21 pmol/L Abnormal result10.8 - 19.3pmol/L

27 Feb 07Serum free T4 level22.3 pmol/L Abnormal result10.8 - 19.3pmol/L

01 Oct 07Serum free T4 level20.1 pmol/L Abnormal result10.8 - 19.3pmol/L

20 Nov 08Serum free T4 level13.9 pmol/L10.8 - 19.3pmol/L

03 Jul 09Serum free T4 level24.5 pmol/L Abnormal result10 - 19.8pmol/L

03 Jul 09Serum free T4 level24.5 pmol/L Abnormal result10 - 19.8pmol/L

16 Jun 10Serum free T4 level19.9 pmol/L12 - 22pmol/L

09 Mar 11Serum free T4 level20.5 pmol/L12 - 22pmol/L

06 Mar 13Serum free T4 level22.8 pmol/L Abnormal result12 - 22pmol/L

31 Jan 14Serum free T4 level21.9 pmol/L12 - 22pmol/L

06 Nov 14Serum free T4 level19.6 pmol/L12 - 22pmol/L

28 Jun 16Serum free T4 level29.1 pmol/L Abnormal result12 - 22pmol/L

06 Oct 16Serum free T4 level27.8 pmol/L Abnormal result12 - 22pmol/L

25 Nov 16Serum free T4 level19.9 pmol/L12 - 22pmol/L


03 Oct 06Serum TSH level9.3 mu/L Abnormal result0.5 - 4.2mu/L

19 Dec 06Serum TSH level0.2 mu/L Abnormal result0.5 - 4.2mu/L

27 Feb 07Serum TSH level0.1 mu/L < Abnormal result0.5 - 4.2mu/L

01 Oct 07Serum TSH level0.1 mu/L Abnormal result0.5 - 4.2mu/L

20 Nov 08Serum TSH level6.8 mu/L Abnormal result0.5 - 4.2mu/L

03 Jul 09Serum TSH level0.1 mu/L < Abnormal result0.5 - 4.2mu/L

03 Jul 09Serum TSH level0.1 mu/L < Abnormal result0.5 - 4.2mu/L

30 Nov 09Serum TSH level0.9 mu/L0.5 - 4.2mu/L

16 Jun 10Serum TSH level0.04 mu/L Abnormal result0.27 - 4.2mu/L

09 Mar 11Serum TSH level0.07 mu/L Abnormal result0.27 - 4.2mu/L

31 Jan 12Serum TSH level2.24 mu/L0.27 - 4.2mu/L

06 Mar 13Serum TSH level0.03 mu/L Abnormal result0.27 - 4.2mu/L

31 Jan 14Serum TSH level0.12 mu/L Abnormal result0.27 - 4.2mu/L

06 Nov 14Serum TSH level0.05 mu/L Abnormal result0.27 - 4.2mu/L

28 Jun 16Serum TSH level0.02 mu/L < Abnormal result0.27 - 4.2mu/L

28 Jun 16Serum TSH level0.02 mu/L < Abnormal result0.27 - 4.2mu/L

06 Oct 16Serum TSH level0.02 mu/L < Abnormal result0.27 - 4.2mu/L

25 Nov 16Serum TSH level0.19 mu/L Abnormal result0.27 - 4.2mu/L

I also found a history of weight and despite being told "it's ok" it's well above the graph I found in my records of my ideal weight.

I would add these results have never been explained to me......



You are lucky having your results online. Many members have to beg for theirs ! ! ...

Your T4 levels were high and are now adequate. TSH (which a pituitary hormone that encourages thyroid hormone to secrete) is low and both of these results evidence you have enough thyroid hormone replacement but as symptomatic, may indicate they aren't being utilised correctly in the body.

Many members have an inability to utilise T4 (Levo) monotherapy due to genetic impairments (DI02). Some members (including myself) have found wellbeing by adding other hormones (T3) or changing meds (NDT).

This mutant gene can be diagnosed via genetic testing (link below) but isn't (yet) generally recognised in general medicine. T4 is the pro-hormone and has to be converted to active T3 that drives the metabolism, giving well being. It would be prudent to have T3 tested.

GP's don't generally test T3 due to cost and members use private labs - link below. It would be very unwise to medicate T3 without establishing your levels.

Any thyroid hormone replacement requires optimal levels of iron and nutrients to work. Ask your GP to test Vit B12, folate, ferritin and Vit D as any deficiencies may impair thyroid hormone synthesis.

Also, as your TSH has jumped about, this may denote Hashimotos Auto Immune Disease. Ask your GP to test thyroid antibodies TPOAb and TGAb and post results complete with ranges. It is useful to know as elevated levels can be very destructive and may be lowered through diet, supplements and a healthy life style.




Private labs testing


DI02 testing


The importance of vitamins and where they may be obtained.

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Thank you I have an appt 23rd Dec with Dr - I will see what he says


Look beyond your thyroid. Are you estrogen dominant, which can cause weight gain?? Over age 35, we tend to make less progesterone, causing estrogen dominance. And, this can lead to female cancers.

Like you, I gained weight over time, and ended up with stage 3 uterine cancer and a ruptured ovary, while my doctor happily sat by and watched...

Best to get on top of this before you go down my path. Have your doctor measure estriol, estradiol, estrone, testosterone, DHEA, progesterone and pregenenolone. And a 24 hour saliva cortisol test, as it could be pregenonlone steal, too. Or better yet, A DUTCH test, if you can get one - google their website - they have some interesting little videos.

And stick with the gluten free diet. You may even want to look into a ketogenic diet to lose weight.


Thank you Learner 1, I had a full hysterectomy in 2000, was on estoradol up until Sept, when due to my age I was weaned off it. A quick look at the ketogenic diet, it looks pretty much like what I eat anyway, without the meat. I will ask the Dr about the other tests.


Unfortunately, people are designed to be omnivores. You need high quality animal protein and fat in your diet along with the other nutrients. I'm quite familiar with vegan and vegetarian diets and had to learn this the hard way myself.

A good read is Gary Taubes book Good Calories Bad Calories. Thoroughly researched, it has a lot of great info on what works with weight loss.

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