Thyroid UK
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Levo dose - pretty confused by my symptoms 😳

I posted 10 days ago after my last blood test regarding my dose of Levo of 100mcg. The results were: TSH: 0.08 (0.3-5.5), FT4: 22.5 (12-22), FT3: 5.8 (3.1-6.8).

I haven't been all that well since, suffering from headaches and overall malaise with fatigue developing throughout the day (I was particularly unwell yesterday). I am pretty fit and have been excercising regularly for years but in the last 3 days I've felt post-exercise lactic acid sensation in most muscles in my body. Now this is something that rarely happens to me even if I have a couple of weeks break in exercise and there was nothing changed in my workout routine - I've been doing the same classes for weeks. Last night, when I was reading in bed about midnight I realised I could feel my pulse all over my body, I checked it and it was almost 90 (my pulse would typically be 52-64 when rested). It continued for about half hour and then subsided and I was able to go to sleep.

As I've been keeping an eye on my symptoms due to the ft4 being a little high I got worried that perhaps I'm taking too much Levo and decided to skip my dose last night. I woke up quite sweaty (this was my daily symptom for over 2 years prior to diagnosis), feeling heavy and with mild swelling in my left eyelid (again this used to be my typical symptom but went away since starting Levo) and swelling in my fingers (not able to move my rings - again this used to be a regular thing for me before Levo).

Now, I'm really confused by this as I didn't think there would be such a reaction to skipping just one dose. Could I really be this sensitive to t4?

Apart from the high pulse rate sensation (which I experienced once a couple of days earlier but not as intensely) I have not noticed any specific symptoms of hyper state although the tiredness and headaches could have been that. Should I try reducing my dose slightly, say take 75mcg once or twice a week instead of 100mcg (when I was on 75mcg every day my tsh was 3.58). Or is it possible that I'm still not well just because my symptoms have not caught up with the blood levels yet and I should just continue with the current dose? Or should I try 100mcg of different brand? I've been taking 100mcg of Actavis but I have MP 50mcg pills left over.

Many thanks for your help!

22 Replies
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sounds to me like your body cannot correctly convert the t4 in levo into the t3 that every cell needs to function

they have not tested free t3 which is totally wrong

usually the reason you cannot convert t4 into t3 is because




vit d3

are below halfway in their ranges

ask your doctor to test them and free t3

when levo cant be converted it builds up in the body like a toxin

try lowering your dose a little till you get aboove results so we can guide you fwd


FT3 results are in the starting post - they are 5.8 with a range of 3.1-6.8

Though you are right there are no vitamin and mineral test results.


Blubug in which case i can but suspect you csnnot tolerate synthetic meds like levo


Hi reallyfedup123. I've had ft3 tested, it was 5.8 (in above post). My ferritin was 77 (15-150) and d3: 91(50-144) and I take enough methylcobalamin and methylfolate to test high🙂


Oh then clearly something else is wrong

maybe you simply cannot tolerate synthetic meds like levo


What were your results before your levo increase? Perhaps for you (and only you can decide) 100 mcg is to high. how did you feel On your previous dose?


On 75mcg only my tsh was tested and it was 3.58. I wasn't feeling great on it but then I don't think there has been any significant improvement since starting 100mcg about 8 weeks ago. So I don't think 75mcg is the answer but maybe something inbetween would work better...


I tried alternating meds it was so hard for me. I found I could not remember what days I had taken what and a lifetime of that would of Sent me crazy lol.

Are your blood tests taken first thing in the morning fasting and no meds the day before?

How far apart was your blood tests from 75 to a hundred x

1 like

Yes the bloods were done before 7am and fasting with previous dose of Levo c. 29 hours before (I take it at night). I've been testing every 6 weeks and at the 4 week mark at each dose I was starting to feel worse, the dose increase made things gradually better but dipped again. I felt very rough about 3 weeks into 100mcg, with very bad mood swings and feeling low but that has now gone.


Do you have your previous t4 result and ranges. I'm thinking I'm not sure but worth asking is 29 hours to long before a blood test without medication. I think it is I'm hoping people can throw some more light on this


You could try reducing it slightly to see if it makes a difference. Perhapss alternate days of 75/100. Your ft4 is a little over range. Have you checked your iron, ferritin, B12 etc to ensure you have max uptake amd conversion?

The other things to consider is has the brand of levo that you use changed? Ive found the fillers in tablets can cause reactions too....


Yes I believe my ferritin and vits are now within the optimal ranges so I don't think any deficiencies are at play and having an impact. I've been using Actavis 100mcg and previously Actavis 50mcg + MP 25mcg and MP 50mcg +MP 25mcg for first week or so before then MP 50 mcg and 25mcg. When being on 75mcg I suspected that MP 25mcg was not quite right for me but I'm now thinking that maybe it was the Actavis that was in the mix at the time that was a problem. Also, I was having a conversation with someone here not long ago about Actavis, which seeemed to be too 'strong' as 100mcg tablet compared to 2 times 50mcg tablets also Actavis. So I'm starting to think now that maybe I should try MP or even Teva to see how I react.


I agree with the suggestion you made yourself in your question. Drop to 75 maybe 2 or 3 times a week and monitor. It may be that your body isn't happy on the high levels that 100mcg levothyroxine is producing.


If you left 29 hours between your last dose, and your blood draw, then your 'true' level of FT4 will be even higher over range. However, your FT3 would still be about 75 % of the range. Therefore, you are not converting very well. If you reduce your T4, your FT3 will also go down, and with your level of exercise, you need it as high as possible. It is low T3 that causes symptoms, therefore you will start feeling even worse.

There are so many reasons why people convert badly, having Hashi's, for example - do you have Hashi's? Low nutrients or cortisol. Or, possibly in your case, the level of exercise. Whatever the reason, it can't always be fixed. The solution is to add a little T3 to a reduced dose of T4 - you really don't want all that unconverted T4 hanging around. It's getting harder and harder to get T3 prescribed, but there is always the possibility of buying your own.


Thank you greygoose. Yes I do have Hashi's confirmed by 3 TPO tests as well as a thyroid ultrasound scan. I've got family history of various autoimmune diseases with both parents and their parents/grandparents...

It is really interesting you saying that my ft4 would be even higer if the time from last Levo was 24 hours instead. I did wonder how my my ft3 would get comfortably within the top quarter of the range, which gets mentioned as being the level where people should be, given that at 5.8 it was just about on the border of the top quarter whilst I was already well saturated with ft4.

I've got a lot of digestive issues (strictly gf for 3 years) and currently started to eliminate dairy. I've had deficiencies of ferritin, d3 and lowish b12 and I have been supplementing ongoing over the last 3 years. Whilst my ferritin and d3 could be higher they are now pretty good, for me. I've had similar level of intensity of excercise for nearly 20 years but I've had to lower the level a bit as I've felt weaker recently.

My GP was pretty good and did not force me to reduce the dose despite the tsh being so low. I did ask him about t3 at the time and he didn't even think nhs prescribes it and said he had no experience of it himself. Given he is the best gp at my surgery (I've gone round the house and tried them all) there is little chance that I would be prescribed liothyronine by him. I feel encouraged, however, that he let me off with this low tsh and high t4 and that I might get away with blood results, if taking liothyronine with Levo (maybe even would not need to come clean as I do not get the impression he was paying much attention to ft4 or ft3 rather just checking if things were in range). I did consider sourcing it myself if there was a need as there is so much information and support on here that I would feel confident in doing it safely. You have confirmed to me that I should be looking at liothyronine (or ndt?) as Levo may not be the best solution for me. Would you be able to PM me with a source of a European supplier or should I do a separate post to ask other members?


It would be better to post a new question, asking exactly that. I don't have any up-to-date supplier links. :)


I need to pick your brains on this. If her t3 result was 5.8 29 hours after last levothyroxine dose, shouldn't we allow for a 20% increase? Or is that just when we take liothyronine separately? Thanks.


As Levo provides only t4, which is stored and converted into t3 by the body, as long as there is enough t4 stored I'd guess the body just tries to convert what it needs. A study which looked at the individual fluctuation of tsh throughout the day showed that tsh is highest in the morning and so is t3, with t4 being pretty stable.


I'm just wondering whether, at 5.8, 29 hours after levothyroxine, your t3 would actually be much higher had you taken levo. It's just that when I did blood test having taken levo both my t4 and t3 levels were substantially higher. So that would make your t3 pushing to top of level. I am just wondering if liothyronine is actually needed. However, it really is your call, your body and only you know what you feel like. It's all trial and improvement for us all. Best wishes.


Interesting. Did you have the tests close together? Supposedly you are ok to take multiple doses of levo together but this would then, based on your observation, this would cause people to go high on ft3 after taking. So saying I'm not quite sure of the mechanism that makes people have ft3 over range when on the ft4 blood level driving the conversion???


It would take much longer than that to have an effet on her FT3. So, no, you shouldn't allow a 20% increase for the FT3, just the FT4.


Hi greygoose. I hope you don't mind me asking another question, please. I skipped one dose of Levo on Monday and took 75mcg of Mercury Pharma in the last 2 days (actually take them in the middle if the night). The first 2 mornings I woke up quite swollen, puffy eyelids and feeling heavy, dragging myself out if bed. This morning I feel a lot better, no swelling at all and feeling actually quite comfortable.

Based on my blood results 2 weeks ago my ft4 was substantially over range (estimated to be 20% higher than actual due to timing of the test at ~27 (12-22)) but ft3 well within range. If it is ft3, which determines how we feel, why was I feeling unwell on 100mcg? Is this because this high ft4 level was likely being converted into rt3 reducing the ft3 which actually got into cells so the ft3 level showing on the test was not what was available? Or could it have been, for example, a filler in the Actavis instead (I've changed brand for the time being to see if it helps, intending to alternate doses of 75 and 100)?

Thank you.


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