Link between high cholesterol & reduction of Levo - Thyroid UK

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Link between high cholesterol & reduction of Levo

Pepekins profile image
19 Replies

I have no thyroid gland it was removed 20+ years ago due to papilliary nodules which turned out to be cancer. During the intervening years levo has been reduced from 150 now down to 100 x 5 & 75 x 2. However each time the dosage is reduced, my cholesterol rises. My endo says it is not good for heart & bones to be over prescribed, so they also have been on at me for years to take a statin. Has any one else noticed this correlation? Also I would like to ask if anyone has had any trouble with their eyes after taking levo for many years


19 Replies
greygoose profile image

There is indeed a correlation. Cholesterol is made in the liver. The liver tries to keep cholesterol levels on an even keel, so the more you consume, the less it makes. The less you consume, the more it makes. But, when the thyroid hormone T3 is too low, the body cannot process and eliminate cholesterol correctly. So, the cholesterol tends to build up in the blood. Raise the FT3 levels and the cholesterol levels will go down.

Levo is T4. T4 is converted to T3. So, if you reduce the levo, the FT3 level will go down as well as the FT4 level.

So, the question is: what is your endos definition of over-prescribed levo? I'm willing to bet he's only looking at the TSH, and has little to no understanding of FT4/3 levels. Is he a diabestes specialist? And, he obviously buys into the myth that a low TSH causes heart problems and osteoporosis, which is totally untrue.

This endo either needs educating, or you need to see another endo that knows something about thyroid - or who has at least read the guidelines! It states clearly (somewhere) that statins are not recommended for hypos because the high cholesterol is more than likely due to under-medication, and because muscle damage on statins is more likely when you are hypo. Well done, you, for resisting them! :)

SeasideSusie profile image


However each time the dosage is reduced, my cholesterol rises

Probably because you are undermedicated causing symptoms of hypothyroidism, one of which is high cholesterol.

What are your latest results?

My endo says it is not good for heart & bones to be over prescribed,

Ask for proof.

What levels are we talking about here? Low TSH?

I have saved some old posts which you might find interesting:

Diogenes is a scientist, researcher and advisor to ThyroidUK.

so they also have been on at me for years to take a statin.

This is what the NHS says about statins and underactive thyroid:

If you have an underactive thyroid (hypothyroidism), treatment may be delayed until this problem is treated. This is because having an underactive thyroid can lead to an increased cholesterol level, and treating hypothyroidism may cause your cholesterol level to decrease, without the need for statins. Statins are also more likely to cause muscle damage in people with an underactive thyroid.

Also I would like to ask if anyone has had any trouble with their eyes after taking levo for many years

I have been taking Levo for 46 years, I have no trouble with my eyes except for what normally happens with ageing - need help with close work/reading so have glasses for that and the beginning of cataracts (not unexpected at 73) but according to the optician will probably be years before any treatment needed.

Pepekins profile image
Pepekins in reply to SeasideSusie

Latest Results Free T4 14.6/ TSH 1.50/ Thyroglobulin 0.1. / Free T3 3.9. Also cholesterol now 8 .3 from 7.2 HDL 2.60 Triglyceride 1.18 LDL 5.16 All up on last year.

SeasideSusie profile image
SeasideSusieAdministrator in reply to Pepekins


TSH 1.50

Free T4 14.6

Free T3 3.9

Thyroglobulin 0.1

Also cholesterol now 8 .3 from 7.2

HDL 2.60

Triglyceride 1.18

LDL 5.16

All up on last year.

I think one of her concerns is that after being lower my TSH is now 1.50 whereas a year ago it was 0.14. A year ago I was taking 7 x 100mcg of Levo, so a reduction now of 0.50 per week.

As mentioned in replies to many of your previous posts, we always need reference ranges when posting results, this is because they vary from lab to lab and to be able to interpret your results we need to see where within the range you are.

Some of your previous posts mention NDT and T3, do you take either of these in addition to your Levo or do you take Levo only?

It would seem that a year ago, with a TSH of 0.14, your GP reduced your dose of Levo from 700mcg per week to 650mcg per week. Well, to be honest, a reduction of 50mcg per week, or 7.14mcg per day, really wasn't worth bothering with.

Now your TSH is 1.5. I wouldn't have thought a reduction of 7.14mcg of Levo per day would have made that much difference.

Do you always do your thyroid tests as we advise every time so that you can accurately compare your results:

* Blood draw no later than 9am. This is because TSH is highest early morning and lowers throughout the day. If looking for a diagnosis of hypothyroidism, an increase in dose of Levo or to avoid a reduction then we need the highest possible TSH

* Nothing to eat or drink except water before the blood draw. This is because eating can lower TSH and coffee can affect TSH.

* If taking thyroid hormone replacement, last dose of Levo should be 24 hours before blood draw, if taking NDT or T3 then last dose should be 8-12 hours before blood draw. Adjust timing the day before if necessary. This avoids measuring hormone levels at their peak after ingestion of hormone replacement. Take your thyroid meds after the blood draw. Taking your dose too close to the blood draw will give false high results, leaving any longer gap will give false low results.

* If you take Biotin or a B Complex containing Biotin (B7), leave this off for 7 days before any blood test. This is because if Biotin is used in the testing procedure it can give false results (most labs use biotin).

[These are patient to patient tips which we don't discuss with phlebotomists or doctors.]

If you had an early blood draw this time and a later blood draw last year this could account for the difference in your TSH. But TSH is not an indicator of thyroid status, it's not a thyroid hormone, it's a pituitary hormone. We need to look at the thyroid hormones - FT4 and FT3 to see where our levels lie to know if we are over medicated or undermedicated, and the FT3 is the most important of these tests, over range FT3 suggests overmedication and the need to reduce our dose of thyroid meds.

So if you can provide the reference ranges for your current tests we will be able to tell you whether you are undermedicated and if this is causing the high cholesterol.

Pepekins profile image
Pepekins in reply to SeasideSusie

Thyroid Function Free T4 14.6 pmol/L 11.5-22.7 TSH 1.50 mu/L 0.55-4.78 Free T3 3.9 pmolL 3.5-6.5 The Ferratin range was about 37 (10-291 ug/L) last year going down a little each year. Thank you for looking these over.

SeasideSusie profile image
SeasideSusieAdministrator in reply to Pepekins


TSH 1.50 mu/L 0.55-4.78

Free T4 14.6 pmol/L 11.5-22.7 = 28% through range

Free T3 3.9 pmolL 3.5-6.5 = 13% through range

The aim of a treated Hypo patient on Levo only, 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.

So there you have it, you are way undermedicated to have such low FT4 and FT3 levels and this is very likely why your cholesterol has risen.

You need an increase in your dose to get your FT4 and FT3 well over half way through range, maybe looking at around 19.5+ and 5.5+ respectively.

You can use the following information to support your request for an increase in dose:

From the British Thyroid Foundation:

How can blood tests be used to manage thyroid disorders?


Occasionally patients only feel well if the TSH is below normal or suppressed. This is usually not harmful as long as it is not completely undetectable and/or the FT3 is clearly normal.

There are also certain patients who only feel better if the TSH is just above the reference range. Within the limits described above, it is recommended that patients and their supervising doctors set individual targets that are right for their particular circumstances.


Also, Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine (the professional publication for doctors):

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l. In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l. This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l).*"

You can obtain a copy of this article from Dionne at ThyroidUK:

print it and highlight Question 6 to show your GP.

I have given you links to posts in my previous reply about why there is no problem with heart and bones if TSH is low. TSH is not a thyroid hormone (FT4 and FT3 are the thyroid hormones), it's a pituitary hormone.


The Ferratin range was about 37 (10-291 ug/L) last year going down a little each year.

This is dire. Were you prescribed anything for this very low ferritin level?

A ferritin level below 30 confirms iron deficiency according to NICE

In all people, a serum ferritin level of less than 30 micrograms/L confirms the diagnosis of iron deficiency.

You are very close to that level. You should have an iron panel done, if serum iron is also low there will be no question about you being iron deficient, also you need a full blood count as this will tell you if you have anaemia. You can have iron deficiency with or without anaemia.

According to some experts the optimal ferritin level for thyroid function is between 90-110 ng/ml.

Have you had Vit D, B12 and Folate tested as well? As ferritin is so low there is a good chance the other nutrients are as well. We need optimal nutrient levels for thyroid hormone to work.

But the take away message here is that you need an increase in your dose of Levo, and not just a tiddly 50mcg per week, you're looking at at least 12.5mcg daily to start with (if not 25mcg), then retest 6-8 weeks later to check your levels.

tattybogle profile image

next time GP suggests statins to deal with raised cholesterol , instead of increasing Levo dose.... point him in the direction of this article from GPonline from 2010. written by Dr Iqbal , a specialist registrar in endocrinology and Dr Krishnan , a specialist registrar in cardiology,

Pepekins profile image

I think one of her concerns is that after being lower my TSH is now 1.50 whereas a year ago it was 0.14. A year ago I was taking 7 x 100mcg of Levo, so a reduction now of 0.50 per week.

humanbean profile image
humanbean in reply to Pepekins

Sorry, I'm confused.

Your TSH is higher than it was a year ago and your doctor wants to reduce your dose of thyroid hormones?

That is completely bananas! If thyroid hormone levels are reduced TSH will rise even higher.

Or have I got the wrong end of the stick?

Pepekins profile image

I wish I knew, obviously I am not the expert here and rely on the endo!

Pepekins profile image

I take various supplements, I wonder if this is having an effect!

pennyannie profile image

Hello Pepekins :

Can I just add that it is essential that you are dosed and monitored on your T3 and T4 thyroid hormone blood test levels and you are move likely to feel at your best when your T4 is heading towards, or in, the top quadrant of the range at around 75% through the range as this should reflect in a higher T3 level and relief of hypothyroid symptms, one of which, is high cholesterol.

Do you have the T4 range for the 14.60 result and the range for the T3 3.90 result ?

If it's the most well used range of 12-22 your T4 result is then just around 26% through the range and if the range for T3 is 3.10-6.80 this is coming in at around 22% ;

The accepted conversion ratio when on T4 only is 1 / 3.50-4.50 with most people preferring to come in at 4 or under. So to find your conversion ratio you simply divide your T3 into your T4 and I'm getting 3.7 - so good conversion, you just need your T4 thyroid hormone increased and build up your dose which will likely lower your TSH but this does not matter.

T4 - Levothyroxine is a storage hormone and needs to be converted by your body into T3 which is the active hormone that the the body runs on. So, a higher T4 - should in turn convert to a higher T3 giving your body more energy to work and support you better.

Conversion can be compromised by low vitamins and minerals so it's important to maintain ferritin, folate, B12 and vitmin D at optimal levels, rather than just somewhere in the range.

The TSH blood test was originally introduced to be used as a diagnostic tool to help confirm a diagnosis of hypothyroidism and was never intended to be used as a measure of any importance once the patient was on any form of thyroid hormone replacement.

A fully functioning working thyroid would be supporting you on a daily basis with trace elements of T1. T2 and calcitonin plus a measure of T3 at around 10mcg + a measure of T4 at around 100 mcg.

T3 - synthetic Liothyronine - is said to be around 4 times more powerful than T4 sythetic Levothyroxine and the average person needs to utilise/ find / convert from T4 around 50 T3 daily, just to function.

As you will see from the above by not restoring the T3 your thyroid was supporting you with, you have in effect been down regulated by some 20% of your overall wellbeing and given time, that is going to take it's toll on your body and can cause additional health issues.

Some people can get by on T4 only, some people find that T4 seems to stop working as well as it once did and need the addition of a little T3 alongside their T4, and some people need to be prescribed T3 only.

I just think it makes common sense that if there has been a medical intervention and the thyroid surgically removed or ablated with RAI that both T3 and T4 should be on the patient's prescription for, if, and possibly when, they will both be needed to restore health and well being.

The thyroid is a major gland responsible for full body synchronisation including your physical, mental, emotional, psychological and spiritual well being, your inner central heating system and your metabolism.

I noticed a previous post about NDT - I too haven't a thyroid though through RAI ablation for Graves Disease in 2005 and now in my third year self medicating and taking NDT and am much improved.

I too was dosed and monitored on just a TSH blood test result and sometimes a T4 reading, and became very unwell when my dose of T4 was reduced to keep my TSH in the range and when I questioned this I was prescribed anti depressants.

A referral to endocrinology in 2018 - to a diabetes specialist didn't help matters, as again, she was only looking at my TSH and not my T3 and T4 levels. I was refused any other treatment options and told I was fine on T4 monotherapy, so decided to try both other thyroid hormone replacements options for myself and have settled on NDT as it feels softer on my body.

Pepekins profile image
Pepekins in reply to pennyannie

Yes looking at result from last few years Free T3 has gone to 3.9 from about 5.2 Free T4 is 14.6 from 18.9 and TSH 1.50 from 0.14. I used to take 125 mcg daily but now, as I said down to 5.x 100 and 2 x 0.75. Felt so awful last night I took a 100mcg tab instead of 0.75 this morning. Years ago when I had to come off Levo for a week due to having tests I remember feeling the same sort of ache under my ribcage, and feeling quite tearful and anxious too.

pennyannie profile image
pennyannie in reply to Pepekins

I'm sure if you reinstate your dose back up to 125mcg you will feel better :

How did you get on with NDT ?

Pepekins profile image
Pepekins in reply to pennyannie

I have never tried NDT, always wanted to, but don't think I could afford as I am almost retired. Bit scared to up my dose too much, probably get an ear bashing from endo!

pennyannie profile image
pennyannie in reply to Pepekins

Oh, sorry - i thought I saw it mentioned on a previous post from you ;

Well, I switched over to self medicating around 3/4 years ago and I'm now 74 :

I found no help with either my doctor nor endo who was, in fact, a diabetes specialist. I just thought, it can' t be worse than how I am and I have to say, it is so much better and liberating. Not being told off as to where my TSH sits and being given anti depressants as a consolation prize, for what in reality was the wrong treatment for someone who has had RAI thyroid ablation for Graves Disease and not well on monotherapy with T4 - Levothyroxine.

Pepekins profile image

Any adice on improving my ferratin level which is about 37? Thanks so much

pennyannie profile image
pennyannie in reply to Pepekins

There are many supplements in the market place :

If you can't tolerate the prescription iron tablets, Gentle Iron by Solgar helped me.

i also took to eating liver and now to maintain my ferritin at around 100 I weekly take a tub of Asda frozen chickens livers and once defrosted, flash fry down into a pate type consistency, a take a spoonful a day for this medicine to go down, especially with a dollop of mayo !!!

Pepekins profile image

Perhaps you would be good enough to pm me as to where you buy the NDT from and if it is a reasonably reliable source.

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