Hi, I'm new to this site but was wondering if anyone is taken Thyroxine and Endep (amitriptyline) and if so if they've had any side effects like confusion and brain processing.

I had radioactive iodine treatment for an overactive thyroid 25 years ago and since then have been on 100mg thyroxine daily. I started menopause 5 years ago and then 2 years ago started to get headaches 24/7 (not migranes just pains which moved around my whole head - eyes, ears, jaw, back of head, top of head, temples. Stabbing, shooting, pounding). I was basically undiagnosed by a neurologist but after trying several migrane and other medications which did nothing he started me on endep. I am now on 25mg and have been for about 18months.

The headache is under control but I have a lot of symptoms of early dementure. I forget where things are or why I'm in a room, I get words mixed up (I'll boil the toaster) I forget the names of everyday items ie calculator, and I seem to have difficulty copying numbers from the calculator to the computer without transposing the numbers.

I'm clutching at straws but this has been getting worse recently and I probably noticed the problem about 6 months ago.

Any ideas??

29 Replies


Welcome to our forum and sorry to hear of your health issues. Low thyroid hormone can encourage brain fog with feelings of confusion, forgetfulness, and lack of focus or mental clarity.

Thyroid imbalance can have a negative effect on the brains serotonin system encouraging depression. Last june I added T3 to my T4 which helped with all my symptoms including terrible brain fog but sent me plummeting into my first ever depression. I started supplementing 5-HTP and focussed on adrenal health which calmed me allowing improved sleep patterns and less heightened emotions. I also doubled my omega 3 daily dose and kept all nutrients optimal.

As you are 5 years into the menopause your doctor may be reluctant to test sex hormones. I had a private test as depression can be the result of a bodily imbalance as well as a brain chemical imbalance. I am menopausal and started bio-identical hormones to address an imbalance in sex hormones (progesterone, testosterone, estrogen, etc.) as this can lead to memory problems & heightened emotions.

Education on thyroid disorders and associated problems gave me back some control of what was a very frightening experience. A good read is “Your Thyroid & How To Keep It Healthy” by Dr Barry Durrant Peatfield” and "A Mind Of Your Own" by Kelly Brogan which gives a scientific & holistic approach to overcoming depression and its causes.

Anti depressants have their place but often come with side effects and don't address the root cause. Ask your doctor to test Vit B12, Vit D, folate and ferritin which are commonly found to be deficient in hypothyroidism and are the very nutrients required for good thyroid hormone synthesis.

Post results together with any recent thyroid hormone test results, complete with ranges (numbers in brackets) for members to comment. A doctors " normal" is not always the same amount that members have found to be most beneficial to their thyroid function.

Forgot to put these links;

Hypothyroidism & mental illness


Overcoming depression when hypothyroid.


amatryptaline isn't just prescribed for depression, it helps with pain as a relaxant and also anxiety type,

Brain fog and memory problems can be associated with food sensitivities.

Worth a trial of cutting out grain and dairy to see if these symptoms improve.

When I was first diagnosed with Graves Disease I was like you - couldn't think of words etc. I used to feel as if people were looking at me as if they couldn't quite understand me when I spoke. I took carbimazole for a while and at one point was given amitriptyline when I was actually needing an increase in my Levo, I don't think it made any difference to my general brain fog. Once my Levo was increased I stopped the amitryptiline. When I was taking the correct amount of Levo the memory problems went back to normal (well my normal) eventually I stopped my block and replace treatment, my thyroid sorted itself out and I'm in remission.

25mcg of Levo isn't a lot (well it wasn't for me) so maybe you are needing more. If you know the results of your blood tests then post them on here along with their lab ranges, it will give anyone looking more of an idea of how you are doing.

You also want to have the usual T3, T4, TSH tests done plus vitamin B12 and Vitamin D. The last two need to be in the top of their ranges to help your thyroid.


My endo said that vitamin D or B12 deficiencies will cause brain fog. Get them tested.

Also I recently started on NDT so I'm getting T4 and T3 with my vitamin supplements there is a vast improvement in my brain fog, I too struggle with words, forget things...

Hope everything works out for you.

Have you had your B12 tested? If so post the results and ranges, also might be worth getting your thyroid bloods done and post them. It I critical that thyroid is tested as early as possible on an empty stomach ( just water) also leave 24 hours from your last dose of thyroxine. Drs are very happy to leave us scraping along the bottom of the barrel as long as THS is Within "range" THS is at its highest first thing and decreases as the morning wears on and after eating. 100mcg seems a low dose for 25 years on thyroxine. Check out the low B12 symptoms and see if any more of those fit. It is very common for thyroid and low B12 to go together. People on here have amazing amounts of knowledge and have helped me enormously so don't be afraid to ask questions even if they seem daft. Honesty these guys make most Drs seem stupid!!

dosage doesn't change for the length of time you're on it, just the test levels and hopefully ( if you get a knowledgeble doctor haha) how you feel

That's real bizarre..... We have 7 members in our direct family who are hypothyroid and all of us have had our dosage increased over the years. Why is that? I don't understand why some people are on huge doses and some are on what seems to be quite small doses. I read it went on weight but someone on here said that wasn't the case, I find it all so confusing.

None of us really know why the variations in doses are as dramatic as they are. The traditional "explanation" is that some people do not absorb it as well as others. Indeed, some time ago I post a case report of a person who needed a large dose and that was put down to gastropariesis.

Basing dose on weight, it seems to me, could only ever work if the dose was being similarly absorbed by everyone.

I am not a medical professional Jac but apparently Endep and 'thyroid meds' ( almost certainly referring to thyroxine) can be problematic when used together:

"Some products that may interact with this drug include: arbutamine, disulfiram, thyroid supplements, other drugs that can cause bleeding/bruising.....etc, etc. " ( WebMD)

Pain is a terrible thing. You have my sympathy. It may well be worth asking the doc to wean yourself of Endep and be ready with an alternative pain relief should you need it. ( Pain itself can be caused by any number of things, of course)

The confusion you report could be the Endep itself, the interaction with your thyroxine or something else entirely. Try not to worry yourself by thinking in terms of dementia but the sooner you see your doctor and kick start some kind of monitored change the better.

My gp put me on low dose of amytriptaline for pain relief, when I was diagnosed with FMS, many years ago. I was like a drunkard, staggering around with no sense of balance and at one point falling down the stairs. It didnt wear off or help with pain relief. I was not being treated for hypothyroid then, though looking back all the signs were there.

hiya... I'm on 200mg thyroxine daily basis. .. going through menopause too. I have noticed the same forgetting words..names.... I had put it down to menopause

Same here. I'm on 150mcg thyroxine and went into menopause at 42. Brain fog is the worst, people look at me as if I'm stupid or insane

Please get your vitamin b12 checked at cell level. Not the serum test. Deficiency can cause confusion and memory loss along with a host of neurological problems. My sister was extremely sick from this and is now on daily B12 shots which are making a massive difference. Also vitamin D levels and ferritin should be checked. Good luck

As others have said, get your B12, Vitamin D, Folate and Ferritin tested.

If your vitamin D is below 125nmol/l then regardless of what the GP says, you need supplements. If you do need supplements, you will also need to add magnesium and vitamin k to your regimen too (also make sure there are no contraindications when taking new drugs, including supplements)

B12, Folate, and Ferritin need to be in up upper quarter of 'normal'

I suffer with the confusion and brain fog, but it's subsiding now my vitamin D and B12 are rising.

Good luck

If you decide to reduce your amitriptyline please do this slowly. A usual dose is 10mg for pain. Have you been referred to a Pain Clinic?

I've had awful confusion. Not side effect. Symptom.

If I am not getting enough Thyroxine, I can hardly function.

Amitriptyline causes less of your thyroxine replacement to be taken up basically they interact with each other negatively. I have used them together before and they do enhance the brain fog. Take them as far apart from each other as possible and either consider to get an increase in levo or reduce the Amitriptyline.

Any anti-depressant negates your thyroxine. Depression is a symptom of UAT not a sign in itself.

I'm prescribed a very low dose of amitryptyline as a sleep aid. I only take it when I'm really desperate for some sleep as it leaves me very hung over and muzzy all the next day.

I was really surprised when my husband was prescribed it for an itchy skin complaint. He was prescribed a much higher dose three times a day. I nagged him until he threw them away!!

As well as making him very confused and disorientated all of the time, it changed his personality. It made him very aggressive and confrontational. It reached the stage that I ( or anyone else ) could not say anything too him with out him taking it the wrong way and him wanting to argue ( or fight!) with me or them. He got more and more aggressive the longer he was taking it. He had no idea he was behaving this way.

He's usually very quiet and never aggressive or argumentative.

I nagged him for three weeks. I told him that he had to stop taking it, I couldn't take his aggression any more. He'd only been taking it for seven or eight weeks. He finally listened to me and threw the tablets away. It took several days for him to return to his usual self.

Yes, thyroid problems can include depression, confusion etc but amitryptyline makes things much worse from my personal experience.

Thank you so much to everybody for their input. I have spent hours trolling the net and couldn't come up with anything. You have all shed a lot of light on the possible causes.

I will arrange a GP appointment to get my bloods done and then get back to you.

Thanks again, Jacqui.

HI Jac66

You just described the bad stuff about Thryroxin. For some reason after many years of use our bodies rebel and say no more. For me it was going gluten free after being diagnosed Coeliac. After being on 150umg of Thyroxin for 3 years with no issues, I could no longer tolerate more than 25umg perday. Please read the flimsy that comes with your Thyroxin, it lists all your issues. Why Endos, Neuros and Docs can't do that I'll never know. Neuros like to prescribe a bunch of other drugs to mange the Thyroxin side effects all with their own side effects - before long you won't know which end is up.

Anyway the answer for me was quit thyroxin and got to natural dedicated thyroid (NDT). It takes a little while to convert for some - for me it took 6 months to stablise. I couldn't tolerate the normal starting dose of NDT 60mg/day. I end up on 30mg/day split in to 4 parts. I am now up to 120mg/day still split up into smaller doses. The issue for me I think was I still had issues with the small percentage of T4 in NDT.

To find a Doc that will prescribe NTD, you have to work backward. Call compounding chemists in your area and find out if they dispense NDT or Porcin or Armour etc. When you find one ask which doctors are writing scripts for it. Find a Doc prepared t prescribe and look after you. You need a Doc in your corner there is no point dealing with 90% of the medical community they sold their souls to the big drug companies. NDT has no patient and the drug companies hate it.

best of luck


I was prescribed amitriptyline for pain relief a few years ago. It triggered sinus tachycardia (very fast heart rate), and although I stopped it when I realised the connection I've never managed to eliminate the tachycardia completely ever since.

Quite recently I was persuaded by a doctor, much against my better judgement, to try nortriptyline, also for pain relief. This is another drug in the same "family" as amitriptyline, but is slightly newer, slightly more expensive, and is allegedly better tolerated. It didn't take long for tachycardia to start up again on a daily basis, although it wasn't as severe as it was with the amitriptyline.

I wouldn't take either amitriptyline or nortriptyline again, nor any drug that was chemically similar.

You often need more hormone after menopause. Your dose was not that high so they should have tried an increase to see if it made a difference. If not, they could have tried an NDT or T3. In other words they should treat your hypothyroidism before diagnosing a new condition. The professionals do not seem to realize the many symptoms of low thyroid.

Amitriptyline is a tricyclic anti-depressant. I have used both the tri-cyclics: doxepin and amitriptyline. These meds are NOT good anti-depressants; and they are not substances which are naturally present in the body, so they have side-effects. I gather you have not heard what many say: T3 is the BEST anti-depressant. Low T3 (active thyroid hormone) will cause dementia-like symptoms such as forgetfulness. Ask your doctor why he/she has not put you on T3+T4, or NDT.

When my B12 was low I felt I was developing dementia. It often accompanies thyroid problems.

I took amitryptiline for couple months and was in a bad shape, I decided to read the pamphlet on the thyroxine and the first name of the drug interaction was amitryptiline, apparently it will enhance the affects of the thyroid medicine so although I was on a low dose of 25mcg of thyroxine I started to have symptoms of hyperthyroidism, I immediately weaned off the amitryptiline and I am glad I did.

OMG I was on exactly the same - Thyroxine and Amitriptyline, with the same symptoms. I was taking the Amitriptyline for fibromyalgiaI. am an Accounts Manager and the confusion nearly drove me crazy. I was convinced I had MS. One day I have a light bulb moment and stopped taking the Amitriptyline ( I decided that I could cope with the pains more than the confusion). I started to feel better within a couple of days. I still have bad patches and the odd patches of confusion, but only when I have these patches ( read my question I posted recently) and that's why I want to get properly sorted. I suggest you read the side effects of Amitriptyline and make up your own mind....

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