Thyroid UK
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Side effects of Levethyroxine

I have been on Levothyroxine since I got thyroid cancer surgery (total thyroidectomy) 5 years ago. The tumors turned out to be small so the surgery was too early.

I have been sick since I took Levothyroxine. I am in my 40's but feels as if I am in my 80's or 90's.

I did not have symptoms for the cancer before the surgery and was not sick before I take medication. After all searches and my experience, I believe my symptoms are mainly for side effect of levothyroxine. My mother had same surgery and same side effect and I find some people taking Levothyroxine have the same or similar symptoms.

At first, I did not think it is side effect of levothyoxine in spite of all test and treatment at many department, doctors do not know the reason and asked me to see a psychiatrist. I saw several of them, but did not work. On the contrary my health got worse faster due to side effects of the medicine, I passed out and was hospitalized at ICU for 4 days.

Anyhow, is there anybody who get T3 only treatment and it works?

I wonder if I can stop T4 and take T3 only though I do not have thyroid gland.

Some people switch to natural thyroid hormone(t4+t3) or T3 only treatment.

I am very sensitive and allergic to filers of drug so some natural natural desiccated thyroid hormone gives me immediate side effect. NP Thyroid does not cause immediate side effect but do not know if it works and how long it will work as I heard after several months natural thyroid hormone did not work for some patients.

If I have no option left, I should try to take T3 only but I don't know if I can find a doctor to treat me that way in the U.S. Most doctors prescribe synthetic T4 only.

Symptoms: bad blood circulation and stiffness (paralysis), blood contacts, arms & legs asleep and cold. fever, sweating, rapid heart beat & increased pulse & blood pressure, brain fog, muscle weakness, pain on butts, hip, thigh, leg, back, shoulder, leg cramps, headache, blood beats, internal vibration, tremor, hair loss, swelling of arm, foot, leg, face, rash, itching, difficulty of breathing. nerve pain, extreme fatigue, dizzy, less focused, loss of memory, etc. (I find all is from the list of side effect of synthroid/

The more I move around or do some activity, symptoms get worse. Can't work not exercise as my thigh, legs, and feet are on pain even on 5 minute's walk. Due to low energy, can't lift or carry things. If I do, I get too exhausted. When lying on bed or seating on chair, pressing points are in too much pain and due to bad blood circulation causing my body asleep and paralyzed (stiff), I can't sleep well nor long.

I wish I did not have the surgery to get rid of total thyroid gland. I did not know side effects of thyroid hormone is this serious and life threatening.

Hormone reacts differently person by person, but if there is anybody who have similar situation, I wonder how you guys are getting through.

14 Replies

Sorry to hear you're so unwell. Do you have your test results (and lab ranges)? You're right, some people just don't feel well on levo alone, but you may well feel just as awful if you're not on enough levo.

You can get alternatives in the US, my mum lives in NJ and is on Armour. I saw her doctor and was prescribed t3. Generally you're better off seeing a 'functional doctor' or a practitioner who describes themselves as 'holistic'. You may find a nurse practitioner or a doctor w an interest in thyroid issues is more flexible than an endocrinologist.

If you know that Np thyroid doesn't bother you, why not give it a go? Do you need to find someone to prescribe it?

Unfortunately for us there is a lot of trial and error involved. I would be inclined to check the test results on levo, see if you're undermedicated or if you're on plenty but it isn't helping. If it is the latter I'd go w Np and ensure you're on enough of it to help.

Test results will help guide you to your next move.


I know the normal range for T4, T3, TSH. I also had Subacute thyroiditis in 2005 and cured in 10 months(it is cured naturally after suffering from hyperthyroidism and hypothyroidism)

Even when test result is normal, I don't feel great and do not feel much difference, but mostly I maintained high level of T4 to keep low TSH (to avoid recurrence of cancer according to my doctor) so I was a little hyperthyroidism, but as time goes by the dosage should be lowered like my mother and other patients (125-100-75), but for me about 2.5 years ago I got hypothyroidism which hormone does not work well or not absorbed due to my bad health condition with a lot of symptoms. So doctors increased to 125 later to 150 then 137...which is too much, causing me rapid heart bit, tremor, more sweating and short of breath. When dosage was reduced the symptoms were mitigated. Psychiatrist misdiagnosed it as panic attach or anxiety due to short of breath and heart beating though it is not mental situation.

Anyhow, I tried erfa(Canada Armour, I bought it abroad) but due to allergy to filler(talc), I could not take it. I am on NP thyroid for 2 weeks with levo as it should be increased every week to 4 weeks so I don't know the result yet but maybe due to dosage is not full now, I feel I am gaining some weight and sign of hypothyroidism. I will continue to increase it to full dosage and see, but my doctor want me to try Tirosint and T3.

She does not much about combination thyroid treatment and NDT and don't like to prescribe NDT. I bought NP thyroid abroad.

I was on Levo + T3 for a few weeks but not much difference. maybe it is because I took T3 once a day, not 4-5 times a day or wrong dosage. for me adding T3 did not reduce side effect of T4.

I am in Los Angeles and looking for doctor who know a lot in thyroid hormone and other important factors including T4,T3,TSH and also can prescribe NDT, T3 or time release T3.


Welcome to the forum, Winjy.

I had thyroidectomy for thyCa 5 years ago. I was recovering on T3 for 3 months while I waited to have RAI but became very unwell when I was switched to Levothyroxine (T4) and after 15 months was mostly bed bound. I stopped taking T4 and switched to T3 for 3 months to clear what I suspected was a build up of T4. When 1 resumed T4 palpitations and breathlessness started within a day. I found adding T3 to Levothyroxine calmed the adverse effects I experienced on Levothyroxine only and have been well on T4+T3 combination since 2014.

If you want sources where to buy T3 without a prescription click on my username and click on Messages top right of my profile page to send me a private message.


Thank you for your reply.

I find some information that T3 is useful and if reveres T3 is high, T3 should be taken. But T3 should be taken 3-5 times a day or time release T3 should be taken not to distort TSH supression and a little hard to optimal point. I heard that T3 only treatment is the last resort.

Glad to hear that you have been well on T4+T3. It is hard to find open minded doctor with undated knowledge & experience who really listen to patients and find solution and treatment in the U.S.

Most of them stick to outdated treatment which is easier to them and do not know much of what is going on for thyroid disease and hormones.



Slow release T3 isn't available in the UK. I was prescribed 3 x 20mcg T3 after thyroidectomy while I was waiting for RAI ablatement and because I'd had thyCa TSH was targetted to be suppressed <0.1. My TSH has been suppressed <0.01 since 2012 although my endo would prefer it around 0.05.

There are quite a number of members taking T3 only, some are prescribed it but some self medicate. I would recommend you try T4+T3 first and if that doesn't suit try T3 only.


In the USA you can get another thyroid hormone treatment which doesn't require a prescription. It was invented by a scientist/doctor/researcher who was an Adviser to It is similar to the very original hormone replacement which was first invented in 1892. I shall give you a couple of links which may be of help. His widow, Tammy, now deals with this part of the website. Natural Dessicated Thyroid Hormones were the very original replacement but then Big Pharma realised that lots of cash could be made so levothyroxine was the result and I believe every country only prescribes this. It doesn't suit everyone (I am one) and we should be able to have options. I shall also give you a link to Dr Lowe's archived site, some items within may not be accessible but most are plus his advice.

I have a thyroid gland and I believe that all of those who've had a thyroidectomy should have, at the very least, the addition of T3.

1 like

Thank you.

I already tried thyro-gold but it caused side effects. Heart, blood beats, tremor and anxiety. I have food sensitivity since I was on Levo. Even herbs or oriental medicine also make rapid heart beats , stomach beats, and restlessness.

I saw other person have the same symptom after taking thyro-gold.

So it is not for me. NP Thyroid does not cause immediate side effect yet but do not fix my problem with Levo yet because I am in the transition (from NP Thyroid to Levo) so I am still taking levo. I will give it a try to quit levo.


Did you begin on a low dose of TG and slowly increase as I have read it is stronger.

I wish you success in your new programme. The following link may be helpful:


I tired one pill. Thank you for your information.


To have such an experience would shake you up, no doubt about that.


My endo said my symptoms are hyperthyroidism which is too much thyroid hormone. But the thing is I have same or similar symptoms even when hormone is low or in a normal range. To keep TSH low, my dosage has been high and hormone has been high in the normal range.

Maybe test result is not right or do not explain my health condition only with free T4, T3, and TSH. One day I did not take T4 and I had less sweat.

NP Thyroid also caused me have fever. It is hard to find the exact dosage but lower is better than more for me as my recent doctor said I have low probability of cancer recurrence due to small tumors so I do not have to keep TSH too low.


I found T4 only treatment have negative effect on brain function so began to take T3 with T4 in the morning. T4 88mcg and T3 10mcg.

Test result on 1/16/2017

T4: 1.2 T3: 2.5 TSH: 1.01

I heard that T3 should be taken 3-5 times a day as it suppresses TSH thus one time dosage can distort blood test result.

Anyhow, I used to keep my TSH very low like 0.02-0.2 and hormone level was high in normal range to prevent cancer recurrence. But most doctors told me I get little chance of getting cancer again, lower than 2% (my tumor was 2mm-3mm in reality, but 4-5mm in sonogram) so my current doctor told me this 1.01 TSH is OK for me.

Before, I used to take 112-125mcg T4 only

Test result on 10/10/2016

T4: 1.5 T3: 3.1 TSH: 0.26

I got surgery in 2011. At first I took 125mcg for 3 month and the lowered to 100mcg.

As time passes it should be lowered to 75mcg according to other people and my mother.

But for me, I was very tired (hair loss & white hair, eczema, dry skin, rash, blurred eyes, digestion problem, lowered immune system, worsened allergy problem, etc) though blood test was in normal range (kept TSH low) and 100mcg was a little too much as my GP pointed out, but my endo in another country(my previous doctor and insisted on surgery) said it should be that way due to low TSH.

Anyhow, my health got worse and levo did not work as it used to be because I became hypothyroidism late 2014 when I felt serious side effects. Bad blood circulation, heart & blood beats, leg cramps, hands&legs were asleep, and stiffness(paralysis), pain on hip including all pressing points so I suffer from extreme fatigue as I woke up with pain and tiredness every morning.

So my TSH increased to 32 thus increasing T4 to 125mcg again.

I had medical check up but doctors did not know the reason and sent me to psychiatrist. I saw a lot of them and they did not know the reason but said when people are physically weak, nerves get weak. Other doctors said there is something wrong with automotive nervous system. In the U.S my psychiatrist and primary doctor thought it was psychiatric problem which I don't agree. But receive treatments to see if symptoms are fixed.

However, last year I almost died with Prosaic for side effects(racing heart beat, seriously dehydrated , vomiting, diarrhea, breathless and choking, powerless, worsened bad blood circulation) after 3 weeks. My health was worse and symptoms got more serious.

Alprazolam (zanax) does not work for me. Cymbalta does not work. Muscle relaxant does not work giving me side effects.

When I first took Cymbalta in 2015 it worked a little for a while (pain on body reduced a little) but after several month it did not work at all and gave me serious side effect. I got very dehydrated causing asthma and choking with rapid heart beat & diarrhea. In Aug 2015 I could not sleep due to choking a few days and vomitted for several hours and then I passed out. I was hopitalized at ICU for 4 days. My friend said my face looked paralized as if I got seizure and I was half conscious for 2 days. After 4 days the doctor asked me to move to general patient room but I went home as I had to participate in my sister's wedding in Germany. When the doctor asked me what medicine I had been taking, I did not remember. Doctor said I was lacking in sodium.

At that time, I got short term memory loss and my nerves got dull and did not feel anything. So I forgot to take levo and did not take it over 15 days and I did not take it to Germany. Though I was dizzy sometimes, my heart did not beat hard and fast nor blood. I did not have pain on body nor stiffness. I also traveled around for 2 weeks in Germany and then my health condition began to get bad(got tired), but not too bad like when I took Levo. When I began to take Levo my symptoms were back and developed everyday.

I also saw oriental doctors and one of them told me, he never saw a patient with a lot of problem with body (this bad condition) like me and it may be thyroid hormone side effect as he saw a lot of patients with thyroid hormone problem. When I took his medicine, my heart beat and anxiety(internal vibration) increase thus I could not sleep and my symptoms were worse.

So every treatment was failed. Seeing doctors and wrong treatment made my health condition and symptoms worse faster than before.

I quit all medicine(psychiatric) except levo for 10 months from Aug 2015 to May 2016 and could not sleep due to pain, so I began to take Ativan(loraxepam) which reduce heart beats, sweating & paralysis a little and makes me sleep a little. Even healthy people get unwell if they can't sleep well for 10 months.

So my health condition is complicated.

Last year my doctor prescribed more and more T4 like 125, 150, 137, 125 and 150 was too much for me as I lost weight and got breathless with rapid heart beats & sweating.

Since 2 weeks ago, I have been taking NP thyroid on my own to see if it works. Other NDT caused immediate side effect due to filers. I took half grain(30mg) plus 25mcg levo and then there is a sign of hypothyroidism so increased levo 50mcg. I took blood test a few days ago but do not know the result yet. I was informed that half grain is equivalent to 50mcg levo so my target is 0.75 gran or 1 grain, but yesterday, I quit levo and took one grain of NP thyroid then it caused a lot of fever as my throat was like on fire and fever was not reduced by aspirin and I got so dry due to fever and had to drink lots of water. So I took half grain this morning so I have less fever but I feel my neck is hot. I have little fever I find that dosage for NDT should not be increased all of a sudden as our body can't handle it.

When I was on levo, I had fever in the afternoon and night and doing some activities I got fever too. I think levo does not work for me except side effect but I do not have options. I have serious metabolism problem. It has been several months since my heart started to beat when I eat food while digesting and sweat. My feet are too cold so I wear 2 pairs of socks on bed.

I know some patient like me. She quit levo for 1.5 month due to pain. Her TSH was 330 so he was hospitalized for 1.5 month and started to take synthroid again as she did not have choice.

The thing is I am extremely sensitive and all functions is down while my sympathetic nerve is too much stimulated and parasympathetic nerve is suppressed. But when I take food or medicine that stimulates sympathetic nerve, my symptoms get worse and restless causing insomnia.

To get less sensitive my immune system should be boosted but there is no way in this situation. Adding T3 did not reduce symptoms including pain. Maybe I should quit all thyroid hormone in a while and then try again.

Sorry for long story.


T3 can be taken once daily. The Recovering with T3 method is suitable for some people but once T3 saturates the receptor cells its effect lasts for between one to three days.


Are gluten free ?


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